Calibrating the coevolution of Ediacaran lifeand environmentAlan D. Rooneya,1, Marjorie D. Cantineb,1, Kristin D. Bergmannb

, Irene Gómez-Pérezc, Badar Al Baloushic,Thomas H. Boagd, James F. Busche, Erik A. Sperlingd, and Justin V. Strausse

aDepartment of Earth and Planetary Sciences, Yale University, New Haven, CT 06520; bDepartment of Earth, Atmospheric, and Planetary Sciences,Massachusetts Institute of Technology, Cambridge, MA 02139; cPetroleum Development Oman, Exploration Directorate, Muscat 100, Oman; dDepartmentof Geological Sciences, Stanford University, Stanford, CA 94305; and eDepartment of Earth Sciences, Dartmouth College, Hanover, NH 03755

Edited by Paul F. Hoffman, University of Victoria, Victoria, BC, Canada, and approved June 1, 2020 (received for review February 15, 2020)

The rise of animals occurred during an interval of Earth history thatwitnessed dynamic marine redox conditions, potentially rapid platemotions, and uniquely large perturbations to global biogeochemicalcycles. The largest of these perturbations, the Shuram carbonisotope excursion, has been invoked as a driving mechanism forEdiacaran environmental change, possibly linked with evolutionaryinnovation or extinction. However, there are a number of contro-versies surrounding the Shuram, including its timing, duration, androle in the concomitant biological and biogeochemical upheavals.Here we present radioisotopic dates bracketing the Shuram on twoseparate paleocontinents; our results are consistent with a globaland synchronous event between 574.0 ± 4.7 and 567.3 ± 3.0 Ma.These dates support the interpretation that the Shuram is a primaryand synchronous event postdating the Gaskiers glaciation. In addi-tion, our Re-Os ages suggest that the appearance of Ediacaran mac-rofossils in northwestern Canada is identical, within uncertainty, tosimilar macrofossils from the Conception Group of Newfoundland,highlighting the coeval appearance of macroscopic metazoansacross two paleocontinents. Our temporal framework for the termi-nal Proterozoic is a critical step for testing hypotheses related toextreme carbon isotope excursions and their role in the evolutionof complex life.

Neoproterozoic | Shuram | Re-Os geochronology | Ediacaran | carbonisotopes

In addition to recording the radiation of animals (1), extremeclimate events (2), oscillating global redox conditions (3–5),

and geomagnetic instability that could be linked to rapid platemotion (6, 7), Neoproterozoic rocks host Earth’s most negativecarbon isotope excursions (CIEs) (8). These CIEs have beeninterpreted to record perturbations to the global carbon cycle ofa magnitude unlike any recorded before or since (9). The largestamong them, the Shuram CIE is globally represented by anabrupt ∼17‰ drop from enriched carbonate carbon isotope(δ13Ccarb) values to highly depleted values of −12‰, beforeslowly recovering to a less enriched background state (10)(Fig. 1). Despite being recorded across more than six paleo-continents and a variety of depositional settings, the Shuram CIEhas remained one of the most enigmatic geochemical events ofthe Proterozoic Eon, with three key controversies surroundingthis event: 1) its onset and duration (11, 12); 2) its primary ordiagenetic origin (13–15); and 3) its temporal proximity andcausal relationship to marine redox fluctuations, glaciation, andthe evolution and/or extinction of the Ediacaran biota (16–20).

Statistical analyses indicate that Ediacaran macrofossils can beassigned into three distinct recurrent taxonomic associations, termedassemblages, that may reflect successive episodes of biotic turnover (23,24). The rise and fall of Ediacaran assemblages is not well constrainedgeochronologically, and the apparent appearances and disappearancesof these assemblages may also be subject to potential paleoenvir-onmental biases. The earliest Avalon assemblage, which consists almostexclusively of fossils preserved in marine slope and basinal depositionalenvironments, is dominated by large fractal organisms (termed fronds)and possible sponges and cnidarians (25). The younger, more diverse

White Sea assemblage includes more complex and mobile taxa such asDickinsonia and the bilaterian Kimberella and largely occurs in marinesubtidal to intertidal shelf settings (26). Finally, the terminal EdiacaranNama assemblage is highly depauperate and dominated by early bilat-erian trace fossils, tubiculous fauna, and the earliest biomineralizinganimals, all of which occur in a variety of shallow-marine carbonate andsiliciclastic environments (27). Although these assemblages appear tohold up across Ediacaran paleocontinents, the fundamental lack ofEdiacaran geochronological constraints has precluded linking bioticturnover to key tectonic or biogeochemical perturbations, such as theShuram CIE (28, 29).

In the absence of a reliable chronology, two age models for theShuram CIE and its relationship to Ediacaran geoevents and bio-events have emerged (28). Both presume the termination occurscirca 550 Ma, an assumption informed by an ash dated to 551.1 ± 0.7Ma above the Shuram CIE in the Doushantuo Formation of SouthChina (30), and which puts the CIE in association with a purportedextinction of the White Sea assemblage (18, 19). Critically, however,these models differ in placing the onset of the Shuram CIE at circa580 Ma (thus potentially linked with the Gaskiers glaciation; ref. 17)versus circa 560 Ma. As a result, estimates for the duration of theexcursion range from <10 to ∼30 My, highlighting an ambiguity incurrent Ediacaran chronologies that makes it impossible to confi-dently link the Shuram CIE to global biogeochemical cycles or theradiation or extinction of soft-bodied Ediacaran fossils.

Significance

Our understanding of the interactions between animal evolu-tion, biogeochemical cycling, and global tectonics during theEdiacaran Period (635 to 541 Ma) is severely hampered by lackof a robust temporal framework. The appearance and extinc-tion of the earliest fossil animals are hypothesized to correlatewith upheavals in biogeochemical cycles—foremost theShuram carbon isotope excursion, possibly the largest knowndisturbance to the global carbon cycle. However, without ageconstraints on the excursion’s timing and duration, its drivingmechanisms, global synchroneity, and role in Ediacaran geo-biological evolution cannot be evaluated. We provide radio-isotopic ages for the onset and termination of the Shuram,evaluate its global synchroneity, and show that it is divorcedfrom the rise of the earliest preserved animal ecosystems.

Author contributions: A.D.R., K.D.B., and J.V.S. designed research; A.D.R., M.D.C., I.G.-P.,B.A.B., T.H.B., J.F.B., E.A.S., and J.V.S. performed research; I.G.-P. contributed new re-agents/analytic tools; A.D.R., M.D.C., I.G.-P., B.A.B., J.F.B., and J.V.S. analyzed data; andA.D.R., M.D.C., and K.D.B. wrote the paper with contributions from all authors.

The authors declare no competing interest.

This article is a PNAS Direct Submission.

Published under the PNAS license.1To whom correspondence may be addressed. Email: alan.rooney@yale.edu or mcantine@mit.edu.

This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.2002918117/-/DCSupplemental.

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Developing a high-resolution chronology for the Shuram CIE hasproven difficult as Ediacaran fossil assemblages only have broadassemblage-scale biostratigraphic utility and previous radioisotopi-cally dated horizons only have provided loose constraints on theShuram CIE’s termination (21, 30). Moreover, chemostratigraphiccorrelations of well-dated fossiliferous Ediacaran successions, suchas the Conception Group of Newfoundland (17) or the CharnianSupergroup of the United Kingdom (31), are not possible due to thepaucity of carbonate sedimentation in those basins. Here, we presenta high-resolution chronology for the Shuram CIE with five rhenium-osmium (Re-Os) dates from mixed carbonate and siliciclastic sedi-mentary rocks bracketing the excursion on two different paleo-continents (Figs. 1 and 2). To develop this age model, we collectedorganic-rich shale and calcareous mudstone samples from theEdiacaran Nafun Group of Oman and the Rackla Group of Yukon,Canada, respectively (Fig. 1 and SI Appendix, Figs. S1 and S2). Thesedates provide critical insights into the timing and tempo of biologicalinnovations and environmental upheavals during the terminalProterozoic.

Geological Setting of the Nafun (Oman) and Rackla (Canada)GroupsThe Ediacaran Nafun Group of Oman is exposed in the central HuqfDesert and northern Oman in the Al Hajar Mountains, and penetrated

by multiple drill cores in the South Oman Salt Basin and Huqf–Haushi High areas (SI Appendix, Fig. S1). In the subsurface and inoutcrops of the Huqf Desert, the Nafun Group has not undergonesignificant metamorphism or deformation, and its sedimentology,stratigraphy, and geochemistry has been extensively studied (32–39).Radioisotopic constraints on the Nafun Group are limited to mini-mum depositional ages derived from detrital zircons (21, 40), al-though extensive dating of volcaniclastic and ash units in theoverlying Ara Group and Fara Formation have yielded latest Edia-caran ages (21).

The Khufai Formation of the Nafun Group is predominantlycarbonate and lies stratigraphically above a Cryogenian (circa 635Ma) Marinoan diamictite and cap carbonate succession. The onsetof the Shuram CIE is captured in the uppermost Khufai Formation(32). The transition to the overlying eponymous Shuram Formationis marked by a sharp shift to siltstone with occasional interbeddedlimestone, which increases in abundance moving up-section (32, 37,38). These interbedded limestone strata record the nadir of theShuram CIE and its subsequent shift to less negative δ13Ccarb values;full recovery occurs in the overlying carbonate-rich Buah Formation(SI Appendix, Fig. S2 and Table S1). In deep-water sections, like thosesampled for this study, a thick silicyte (rock containing >90% cryp-tocrystalline silica) occurs in the upper Buah Formation (41). Anunconformity between the Buah Formation and overlying carbonateand evaporite of the Ara Group is often seen in the subsurface; in the

Fig. 1. Simplified stratigraphy and chemostratigraphy of Ediacaran sedimentary rocks in northwestern Canada and Oman. Sampled horizons indicated withstars and compilation of carbon isotope data are in SI Appendix, Table S1. Previously published geochronological constraints are from U-Pb zircon ages on ashbeds (21) and Re-Os ages on organic-rich sedimentary rocks (22). Fm, Formation.

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Oman Mountains, the Buah is overlain by volcaniclastic strata of theFara Formation (39, 42, 43). Fossils of Ediacaran biota are not knownfrom any Nafun Group strata, but Cloudina and Namacalathus arereported in Ara Group drill core (44). Two cores, Well L and Well M,drilled by Petroleum Development Oman in the last decade, samplethe deepest water environments of the South Oman Salt Basin (SIAppendix, Fig. S1). The stratigraphic position of samples fromWells Land M are shown within the context of Thamoud-6, a deep-water wellthat has been described previously (10, 34, 37, 39, 44) (SI Appendix,Figs. S1 and S2).

The Rackla Group is exposed throughout the Mackenzie, Wer-necke, and Ogilvie Mountains of Yukon and Northwest Territories,Canada (45) (Fig. 1 and SI Appendix, Fig. S3). Rackla Group strata inthe Wernecke and Mackenzie Mountains overlie a circa 635 MaMarinoan glacial-cap carbonate succession and begin with theSheepbed Formation, the base of which is dated to 632.1 ± 5.9 Ma(22). The Sheepbed Formation is overlain by mixed carbonate andsiliciclastic strata of the Nadaleen Formation (45) (previously termed“June beds” in ref. 29), which hosts Avalon assemblage Ediacaranmacrofossils, including the discoid fossils Aspidella and Hiemolora, theerniettomorph Namalia, and various rangeomorphs (46). TheNadaleen has highly enriched δ13Ccarb values up to +9‰ (Fig. 1).The overlying carbonate-dominated Gametrail Formation hosts anabrupt drop in δ13Ccarb values as low as −13‰ within the nadir of theShuram CIE (29, 45), before recovering to values around 0 to +2 nearthe contact with the overlying Blueflower Formation. The Blueflowercontains a diverse assemblage of trace fossils, rangeomorphs, tubularand discoid fossils, and a putative dickinsoniid (47). These strata arefollowed by the terminal Ediacaran carbonate-dominated Algae andRisky formations, which are both unconformably overlain by lower-most Cambrian strata of the Narchilla and Ingta formations, re-spectively, which host small shelly and diverse trace fossil assemblages(29, 45).

Ediacaran strata of the Ogilvie Mountains (Rackla Group) comprisea series of informal map units labeled PH3 and PH4 (29, 48, 49) (SIAppendix, Fig. S3). Unit PH3 consists predominantly of black shale thatdirectly overlies an unnamed Cryogenian glacial deposit and cap

carbonate pair belonging to the circa 635-Ma Marinoan glaciation (29).This is succeeded by the Shuram CIE-bearing unit PH4, which recordsan abrupt shift to highly depleted δ13Ccarb values down to −9‰ (45) (SIAppendix, Table S1). A concretionary limestone unit at the top of unitPH4 has been loosely correlated with the Blueflower Formation andrecords a return to enriched δ13Ccarb values of 0 to +2‰ (SI Appendix,Fig. S3). Units PH3 and PH4 are truncated by an angular unconformitybeneath informal unit PH5, which is composed of siltstone and sand-stone that contain diagnostic early–middle Cambrian trace fossils (48).

Re-Os GeochronologyTwo samples of organic-rich shale of the Khufai and Buah forma-tions were retrieved from Well L and Well M of the South OmanSalt Basin for Re-Os geochronology (Fig. 1; SI Appendix, Fig. S1;and Materials and Methods). Samples from Well L of the basalKhufai Formation were deposited prior to the onset of the ShuramCIE and yield a Re-Os depositional age of 578.2 ± 5.9 Ma (2σ, n = 7,mean square of weighted deviates [MSWD] = 0.97 [all isochronsgenerated in this study are model 1, and total uncertainties includethe uncertainty in the 187Re constant, λ; ref. 50]), with an initial187Os/188Os (Osi) value of 1.15 ± 0.05 (Fig. 2A and SI Appendix,Table S2). Buah Formation samples from Well M, which record thepost-Shuram recovery to positive δ13Ccarb values, yield a depositionalage of 562.7 ± 3.8 Ma (2σ, n = 7, MSWD = 1.40) with an Osi value of0.68 ± 0.01 (Fig. 2B).

Three samples from black calcareous mudstone horizons in theRackla Group were sampled for Re-Os geochronology in order tobracket the Shuram CIE in northwestern Canada (Figs. 1 and 2 andSI Appendix). Sample J1719 of the upper Nadaleen Formation in theWernecke Mountains yields a pre-Shuram Re-Os depositional age of574.0 ± 4.7 Ma (2σ, n = 8, MSWD = 0.75) with an Osi value of0.60 ± 0.01 (Fig. 2C), and sample J1443 of the upper NadaleenFormation yields a similar depositional age of 575.0 ± 5.1 Ma (2σ,n = 5, MSWD = 1.20) with an Osi value of 0.60 ± 0.01 (Fig. 2D).Above the Shuram CIE, sample A1707 from map unit PH4 inthe Ogilvie Mountains yields a post-Shuram depositional age of

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187Re/188Os 187Re/188Os

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Age = 575.0 ± 5.1 Ma

Initial 187Os/188Os = 0.61± 0.01

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Fig. 2. Re-Os isochron diagrams for dated horizons. (A) Well L: Khufai Formation, Oman. (B) Well M: Buah Formation, Oman. (C) J1719: Nadaleen Formation,Wernecke Mountains, Yukon. (D) J1443: Nadaleen Formation, Wernecke Mountains, Yukon. (E) A1707: unit PH4, Ogilvie Mountains, Yukon. All isotopiccomposition and elemental abundance data are presented in SI Appendix, Table S2.

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567.3 ± 3.0 Ma (2σ, n = 6, MSWD = 0.81) with an Osi value of0.61 ± 0.04 (Fig. 2E).

Onset, Duration, and Synchroneity of the Shuram CIEExcursionThe geochronological data presented here yield consistent andoverlapping age constraints for the onset and termination of theShuram CIE on separate paleocontinents. In Oman, onset of theexcursion occurred after 578.2 ± 5.9 Ma, with termination by 562.7 ±3.8 Ma; the excursion’s duration in Oman is thus constrained to beless than 15.5 ± 7.0 My (Fig. 3). In northwestern Canada, the ex-cursion is constrained to have lasted no more than 6.7 ± 5.6 My,beginning after 574.0 ± 4.7 Ma and ending by 567.3 ± 3.0 Ma (Fig. 3and SI Appendix, Tables S1 and S3). A recent study of siliciclastic-hosted δ13Ccarb data from fossiliferous strata in the ConceptionGroup of Newfoundland noted an isotopic trend, potentially cor-relative with the Shuram CIE (51), that is temporally constrainedbetween 574.17 ± 0.66 and 562.5 ± 1.1 Ma (17, 51, 52). These datesare compatible with those from Oman and northwestern Canada,and if this isotopic trend is correlative with the Shuram CIE, thesedata suggest a duration in Newfoundland of less than 11.7 ± 1.3 My(Fig. 3). Critically, the Re-Os dates from northwestern Canada andOman demonstrate that the Shuram CIE is recorded in coeval strata onmultiple paleocontinents within analytical uncertainty, consistent with aglobal and synchronous event. These constraints also permit in-terpretation of the Shuram CIE as a series of short and asynchronousevents in separate basins in this time window. However, the ShuramCIE—which exhibits remarkable consistency in its expression acrossmultiple successions (9)—is more parsimoniously interpreted as a singleisochronous event. The congruence of ages from multiple paleo-continents also suggests an accuracy for the mean ages that is greaterthan the strict uncertainty derived for individual ages. Interpretation ofthe Shuram CIE as a synchronous event indicates that the excursionoccurred in all locations after 574.0 ± 4.7 Ma. This temporal frameworkindicates the Shuram CIE is at least 5.2 ± 4.8 My younger than the

Gaskiers deglaciation (17), severing a potential mechanistic link to theimmediate aftermath of glaciation as a driver for the excursion (Fig. 3).

Toward Calibration of the Ediacaran PeriodThe dates presented herein have important implications for theappearance of macroscopic eukaryotes in the fossil record of north-western Canada and globally (Fig. 4). A recently dated ash in the DrookFormation of Newfoundland ∼25 m above the first appearance of ive-sheadiomorphs and frondose fossils constrains the appearance of theEdiacaran biota to >574.17 ± 0.66 Ma (52) (Fig. 4). The 574.0 ± 4.7 MaRe-Os date from the Nadaleen Formation is identical, within un-certainty, suggesting these organisms were globally distributed and likelyappeared before the Shuram CIE based on their stratigraphic distribu-tion in northwestern Canada (Fig. 4). It has been proposed that Avalontaxa originally evolved in deep-water habitats as a physiological refuge(53); the significance of this synchronous first appearance datum innorthwestern Canada and Newfoundland remains unclear, but it is atleast consistent with the hypothesis that deep-water slope environmentson different continental margins harbored early macroscopic life.

Calibration of the Shuram CIE also unexpectedly divorces thestratigraphic and/or evolutionary appearance and disappearance ofthe Ediacara biota from previously hypothesized environmental driv-ers (16, 18). Based on the available data, the Avalon assemblage ap-pears after the Gaskiers glaciation but before the onset of the ShuramCIE and associated marine oxygenation (Figs. 3 and 4 and SI Ap-pendix). The geochronological data reported herein support a revisedage model for Member IV of the Doushantuo Formation of SouthChina, now assigning Member IV (which records the termination ofthe Shuram CIE) an age of circa 565 Ma (30). This means thatmodeled estimates of the areal extent of global seafloor euxinia de-rived from δ98Mo data in Doushantuo Member IV euxinic shale andδ238U data from uppermost Doushantuo Member III carbonates (54)are older than previously assumed, with proposed global ocean oxy-genation occurring by circa 565 instead of 550 Ma (16, 54). This is instrong contrast with the pre-Shuram interval, when 25 to 100% of theglobal seafloor was estimated to be anoxic (Fig. 4), thereby implyingan ocean oxygenation event is associated with the Shuram CIE. It washypothesized that this oxygenation may have driven or otherwiseallowed for the appearance of the White Sea assemblage (16) due totheir likely higher oxygen requirements (55); however, our age modelfor the Ediacaran Period indicates that marine oxygenation as recor-ded in these geochemical proxies significantly predates the appearanceof White Sea assemblage fossils. There actually may be little to nopublished redox geochemical data that is demonstrably from the circa560 to 555 Ma window when the White Sea assemblage first appearsin the fossil record. In contrast to recent suggestions (18, 19), thetemporal constraints on the Shuram CIE presented here suggest it isdisconnected from the extinction of the White Sea assemblage at circa550 Ma (Fig. 4).

There are still important nuances to consider in connecting theShuram CIE with records of animal evolution, including preserva-tional controls on the appearance of fossils (56) and long-enduringquestions of the permissible temporal lag between environmentalchange and biotic response. However, our temporal framework forthe terminal Proterozoic suggests that evolutionary dynamics in theEdiacaran Period were, at face value, potentially decoupled fromdramatic environmental changes. This finding highlights the impor-tance of a robust geochronological framework for linking Pro-terozoic environmental change with the fossil record.

The synchronous onset and termination of the Shuram CIE in atleast two, but possibly three, sedimentary successions from differentpaleocontinents with different lithological expressions and sedimentaccumulation rates is difficult to reconcile with a diagenetic originfor the excursion. Alteration by hydrothermal (13) or meteoric wa-ters (15) would not be expected to produce similar styles of alter-ation of different lithofacies over variable stratigraphic thicknessesof similar durations. Moreover, the Shuram CIE is virtually uniquein its stratigraphic expression and well characterized in marine strataover multiple paleocontinents and paleolatitudes (9); our docu-mentation herein of its occurrence within radioisotopic analyticaluncertainty across different paleocontinents bolsters interpretation

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Fig. 3. Probability distributions of ages from this study and others (17, 51,52) (note use of age from ref. 52 for the Pizza Disc ash bed used both as 1)the minimum age of the first Ediacara biota preserved in Newfoundland and 2)the maximum age of the Shuram-like isotope trend described by ref. 51). Theminimum duration of the Shuram CIE or Shuram-like isotope trend in each lo-cation is shown. Assuming a synchronous global Shuram CIE, the preonset age(574.0 ± 4.7 Ma) from northwestern Canada suggests at least 5.2 ± 4.8 My be-tween Gaskiers deglaciation and the onset of the CIE. This is supported by arecently observed isotope trend in siliciclastic-hosted carbonate in Newfound-land (51), which may be correlative to the Shuram CIE and is stratigraphicallyand geochronologically distinct from the Gaskiers deglaciation. An ash in theTrepassey Formation (Fm) above this trend constrains it to >562.5 ± 1.1 Ma (51);an ash within theMistaken Point Fm, associated with negative values, is dated to565.00 ± 0.64 Ma (52). Ages in blue are Re-Os ages from organic-rich rocks (thisstudy); all others are chemical abrasion–isotope dilution–thermal ionizationmass spectrometry U-Pb ages measured on zircon (17, 51, 52).

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of the Shuram CIE as a primary global event—potentially one of thelargest global carbon cycle perturbations in Earth’s history. Thesegeochronological data do not necessarily require that the ShuramCIE record global open-marine dissolved inorganic carbon (DIC)isotopic compositions; a range of carbonate platform-related pro-cesses (e.g., refs. 57–59) may result in discontinuities in the isotopiccompositions of different DIC pools. Critically, these dates providekey information for assessing these and other mechanisms capable ofgenerating such a large, synchronous, and sustained shift in theisotopic composition of Ediacaran carbonate systems.

ConclusionsRadioisotopic dates for the onset and termination of the ShuramCIE across multiple paleocontinents provide evidence for the CIE asa primary and synchronous global event lasting no more than 6.7 ± 5.6My. Together with associated redox geochemical data from coevalsedimentary successions (16, 29, 54), these geochronological data alsoconnect the highly depleted δ13Ccarb values of the Shuram CIE to aperiod of relative ocean oxygenation. This resolved chronology for theEdiacaran Period decouples the Shuram CIE from the Gaskiers gla-ciation circa 580 Ma and the extinction of the White Sea fauna circa550 Ma and highlights the coeval appearance of macroscopic meta-zoans across two paleocontinents (Fig. 4). This emerging chronologyprovides essential context for evaluating the mechanisms capable ofdriving an extraordinarily negative and extended CIE and assessing itsimpact on the habitats and evolution of early animals.

Materials and MethodsSampling for Re-Os Geochronology.Approximately 30 g of carbonaceous shaleand mudstone was sampled from outcrop and drill core in the Nadaleen,Blueflower, Khufai, and Buah Formations, as well as map unit PH4. Similar tomethods outlined previously (60), for outcrop samples, an approximately25-cm-deep trench was dug into the outcrop to avoid sampling surficialweathered material, and sampling was undertaken horizontally for up to65 cm along a single <3-cm-thick horizon to maximize the spread of 187Re/

188Os values (61). Drill core samples (Oman) were taken over an interval of0.8 and 1.41 m for the Khufai and Buah Formations, respectively. Samplingin core was driven by facies and TOC data, targeting organic-rich shales withup to 6% TOC. Although sampled vertically, all initial 187Os/188Os values forthe Khufai and Buah Formations displayed very little internal variation (SIAppendix, Table S2).

Carbon and Oxygen Isotope Geochemistry. Carbonate rock samples fromnorthwestern Canadawere analyzed at bothDartmouth College and the YaleAnalytical and Stable Isotope Center; 0.1- to 0.5-kg samples of limestone anddolostone were collected approximately every meter throughout detailedmeasured stratigraphic sections and targeted to avoid obvious fracturing orveining. The samples were then slabbed perpendicular to bedding using alapidary saw, and ∼5 to 10 mg of powder was drilled from individual lami-nations using a drill press with a dental carbide drill bit. Carbonate powdersanalyzed at Dartmouth College (JB1704, J1711, JB1707, T1701, J1713, andJB1801) were reacted with phosphoric acid (H3PO4) at 70 °C on a Gasbench IIpreparation device attached to a ThermoFinnigan DeltaPlus XL continuousflow isotope ratio mass spectrometer. δ13Ccarb and δ18Ocarb were measuredsimultaneously, and isotopic data are reported in standard delta notation asthe per mil difference from Vienna Pee Dee Belemnite (VPDB). Precision andaccuracy were monitored by running a total of 12 standards for every 76samples using 11:3 sample/standard bracketing. The standard set includestwo external standards (National Bureau of Standards [NBS]-18 and Ele-mental Microanalysis [EM] Carrara Marble), as well as an internal marblestandard. Samples are measured relative to an internal CO2 gas standard andthen converted to the VPDB scale using the known composition of NBS-18(δ13C = −5.01; δ18O = −23.20) and the EM-Carrara Marble (δ13Ccarb = 2.10;δ18Ocarb = −2.01). Measured precision was 0.1 to 0.15‰ (1σ) for δ13Ccarb and0.15 to 0.2‰ (1σ) for δ18Ocarb. Samples run at the Yale Analytical and StableIsotopic Center (J1719) followed an identical procedure using a KIEL car-bonate preparation device connected to a ThermoFinnigan MAT 253. Thestandard set includes the MERC (δ13C = −48.96; δ18O = −16.48), PX (δ13Ccarb =2.25; δ18Ocarb = −1.79), and YM (δ13Ccarb = −1.59; δ18Ocarb = −6.03) standardswhich were calibrated against the NBS-19, NBS-18, and LSVEC internationalstandards on the VPDB scale. Internal precision was reported as 0.1 to 0.15‰

Fig. 4. Composite carbon isotope curve, age constraints, and fossil occurrences for the Ediacaran Period. References used for carbon isotope curve and agemodel are listed in the SI Appendix. *, U-Pb TIMS zircon date; †, U-Pb SHRIMP zircon date; ‡ indicates Re-Os date. The same color is used to plot both ages andchemostratigraphic data from the same location; dark green ages are from Newfoundland. Dates in bold are Re-Os ages from this study; bolded dark blue ages arefrom Oman, and bolded light blue ages are from northwestern Canada. Global diversity, ranges of Ediacara biota constituents, and animal ichnogenera follow (18).Percent anoxic seafloor area derived from mass balance modeling of Mo and U isotopic data are from refs. 16, 54. WS, White Sea; Frt., Fortunian; £, Cambrian.

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(1σ) for δ13Ccarb and 0.1 to 0.15 ‰ (1σ) for δ18Ocarb. Carbon and oxygenisotope geochemistry for Oman are from ref. 39. All data necessary forreplication are included in the submission and/or publicly available fromA.D.R. and M.D.C.

ACKNOWLEDGMENTS. We acknowledge Sierra Anseeuw at Yale for analyt-ical support and Zuwena Al-Rawahi and Elena Mihaly for sampling support.We thank the Ministry of Oil and Gas of the Sultanate of Oman forpermission to access samples and publish their results. The Yukon GeologicalSurvey (YGS), ATAC Resources, and the Geological Survey of Canadaprovided logistical support in Yukon, Canada. M.D.C. was supported by aNational Defense Science and Engineering Graduate Fellowship, K.D.B.

acknowledges support from the David and Lucile Packard Foundation andPetroleum Development Oman, and T.H.B. was supported by a NationalScience and Engineering Research Council Doctoral Fellowship. Fieldwork innorthwestern Canada was supported by the YGS, Government of YukonPaleontology Program, Dartmouth College, the National Geographic Society(Grant CP-102R-17 awarded to E.A.S. and Grant EC-393R-18 awarded toJ.F.B.), the National Science Foundation (Grant EAR-1654131 awarded toJ.V.S.), and grants from the American Philosophical Society Lewis and ClarkFund (awarded to T.H.B. and J.F.B.) and Stanford McGee-Levorsen funds(awarded to T.H.B.). Thoughtful criticism from editor Paul Hoffman and twoanonymous reviewers improved this manuscript.

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Supplementary Information for

Calibrating the co-evolution of Ediacaran life and environment

Alan D. Rooney, Marjorie D. Cantine, Kristin D. Bergmann, Thomas H. Boag, James F. Busch,

Erik A. Sperling, Justin V. Strauss

Alan D. Rooney and Marjori D. Cantine.

E-mail: alan.rooney@yale.edu mcantine@mit.edu

This PDF file includes:

Supplementary text

Figs. S1 to S3

Tables S1 to S3

Supplementary File references

www.pnas.org/cgi/doi/10.1073/pnas.2002918117

17

Supplementary Information Text

Geological Setting: Oman

The Ediacaran Nafun Group of Oman is exposed in outcrop in the southern Huqf Desert and

northern Oman Mountains (Al Hajar Mountains) and is extensively penetrated by drillcore in the

South Oman Salt Basin and Huqf-Haushi High areas (Fig. S1). In the subsurface and Huqf Desert,

the Nafun Group is exceptionally well-preserved and has not undergone significant metamorphism

or burial. The sedimentology, stratigraphy, and geochemistry of the Nafun Group has been

extensively studied (1-23), in part motivated by the presence of hydrocarbon resources and in part

because its exceptional preservation offers the opportunity to study proxy records that have been

obscured or obliterated in many other Ediacaran successions. Proxy records examined in Oman

have included carbonate clumped isotopes (15), biomarkers (5-7, 12) and carbonate-associated

sulphate (10, 11).

The Nafun Group overlies the Abu Mahara Group, which contains diamictites correlated with

Cryogenian glaciations, and the Nafun Group’s basal Hadash Formation (Fm) is correlated with

the post-Marinoan cap carbonate globally. The Nafun Group is a mixed siliciclastic-carbonate

deposit with two major cycles of siliciclastic-to-carbonate deposition. The lower cycle is

represented by the Masirah Bay and Khufai formations, and the upper cycle by the Shuram and

Buah formations. Both cycles are characterized by lithofacies assemblages consistent with a

shallowing upwards pattern (15).

The Masirah Bay overlies the Hadash Fm, the Cryogenian Ghadir Manquil Fm, or the Halfayn

volcanic suite depending on the location. The Masirah Bay Fm is dominantly siliciclastic, with

shales, siltstones, and sandstones, though in it contains interbedded shales and dolomites near its

top (16). Its upper contact with the Khufai Fm is transitional, from thinly bedded shales and

dolomites into continuous carbonate (21). The Khufai Fm contains both limestones and dolomites

and was deposited in a ramp setting (11, 21). Fetid carbonates are common, as are grainstones and

silicification. The onset of the Shuram CIE is captured in the uppermost Khufai Fm, and its contact

with the Shuram Fm in the Huqf Desert is marked by a laterally continuous oolite on which

cauliform stromatolites nucleated (2; Table S1). The transition to the Shuram Fm is also marked

by a sharp shift to silicilastic siltstone with occasional interbedded limestones, which increase in

abundance moving upsection (2, 9, 21). Shuram Fm limestones often contain ooids and edgewise

conglomerates and siltstones in the Huqf Desert typically contain hummocky and swaley cross

18

stratification (9, 21). Full recovery to positive δ13C values occurs in the overlying, carbonate-

dominated Buah Fm (2, 3, 19, 21, 23; Fig. S2; Table S1). In deep-water sections, a thick silicilyte

(rock containing >90% cryptocrystalline silica) occurs in the upper Buah Fm. An unconformity

between the Buah Fm and the overlying carbonates and evaporites of the Ara Group is often seen

in the subsurface, while in the Oman Mountains, the Buah is overlain by the volcaniclastics of the

Fara Fm (16).

Radioisotopic constraints on the Nafun Group are limited to minimum depositional ages

derived from detrital zircons (17). Extensive dating of volcaniclastic and ash units in the overlying

Ara Group from the Oman Mountains and South Oman Salt Basin have yielded latest Ediacaran

ages (17). Fossils of Ediacaran biota are not known from any Nafun Group stratigraphy, but

Cloudina and Namacalathus are reported in Ara Group drillcore (20).

Two drillcores, drilled by Petroleum Development Oman in the last decade, sample the deepest

water environments of the South Oman Salt Basin (Fig. S1). We refer to them as Well L and Well

M. Carbon isotope data, sedimentology, and gamma ray data guide the correlation of these cores

both to other subsurface wells and to outcrop in the Huqf Desert and Oman Mountains. Correlation

of Wells L and M to Thamoud-6, a well that has been previously described is shown in Figs. S1,

S2), with stratigraphic location of Re-Os samples sampled for this study. Organic-rich shale

intervals were targeted for Re-Os geochronology. Sample suites comprise up to 9 subsamples

taken within intervals up to 1.4 meters in total thickness.

Geological Setting: NW Canada

In the Wernecke and Ogilvie Mountains of Yukon, Canada, Neoproterozoic rocks of the

Windermere Supergroup (ca. 780-540 Ma) consist of a ca. 6 km thick mixed carbonate-

siliciclastic succession deposited along the northwestern margin of Laurentia (24-26). Ediacaran

strata of the Wernecke Mountains comprise the recently formalized Rackla Group (27), which is

composed of the Sheepbed, Nadaleen, Gametrail, Blueflower, Algae, and Risky formations (24,

25, 27-30; Fig. S3). The ca. 632 Ma Sheepbed Formation locally overlies glaciogenic diamictite

(Rapitan Group) and cap carbonate (Ravensthroat Formation) of the Cryogenian Marinoan

glaciation (27, 28, 31-34). These strata are overlain by mixed siliciclastic and carbonate strata of

the Nadaleen Formation, which locally contains the Ediacaran macrofossil Aspidella and are

characterized by highly enriched δ13Ccarb values up to +9‰ (ref. 27). The overlying Gametrail

19

Formation contains highly depleted δ13Ccarb values down to -13‰ that have been correlated

globally with the Shuram CIE (27, 28; Table S1); this unit records an abrupt return to positive

δ13Ccarb values near the top of the formation and its contact with the overlying Blueflower

Formation (Fig. 1; Extended Data Fig. 3). The Gametrail Formation is overlain by mixed

siliciclastic and carbonate strata of the fossiliferous Blueflower, Algae, and Risky formations, the

latter of which lies at or just below the Ediacaran-Cambrian boundary (25, 29, 35-37).

Ediacaran–Cambrian strata of the Ogilvie Mountains comprise a series of informal map units

labeled PH3, PH4, and PH5 (28, 38-41; Fig. S3). Units PH3 and PH4 were previously correlated

with the informal “upper group” (28), but recent formalization of the Rackla Group suggests

these units instead belong within this newer lithostratigraphic unit (27). Unit PH3 consists

predominantly of black shale and mudstone that directly overlies an unnamed Cryogenian glacial

deposit and cap carbonate pair belonging to the ca. 635 Ma Marinoan glaciation (28, 39). This is

succeeded by unit PH4, which is composed primarily of hummocky cross-stratified dolostone,

silty dolostone, and rare dolorudstone with interbedded black shale and concretionary limestone

near its top. These strata record highly depleted δ13Ccarb values down to -9‰, which have

previously been correlated with the Shuram CIE (27; Table S1). The concretionary limestone

unit at the top of unit PH4 has been loosely correlated with the Blueflower Formation and

records a return to enriched δ13Ccarb values (Fig. S3). Locally, units PH3 and PH4 are truncated

by an angular unconformity beneath unit PH5, which is composed of siltstone and sandstone that

contain diagnostic early-middle Cambrian trace fossils including Skolithos, Cruziana, and

Rusophycus (38).

Re-Os geochronology

All radioisotopic analyses were performed at the Yale University Metal Geochemistry and

Geochronology Center. Weathered surfaces were removed with a diamond-encrusted rock saw and

samples were then hand-polished using a diamond-encrusted polishing pad to remove cutting

marks and eliminate any potential for contamination from the saw blade. The samples were dried

overnight at ~40 °C and then crushed to a fine (~30 μm) powder in a SPEX 8500 Shatterbox using

a zirconium ceramic grinding container and puck in order to homogenize any Re and Os

heterogeneity present in the samples (42). The Re and Os isotopic abundances and compositions

were determined following methodologies previously described (43, 44).

20

Between 0.15 and 1 g of sample was digested and equilibrated in 8 ml of CrVIO3-H2SO4

together with a mixed tracer (spike) solution of 190Os and 185Re in carius tubes at 220 °C for 48

hours. Rhenium and Os were isolated and purified using solvent extraction (NaOH, (CH3)2CO,

and CHCl3), micro-distillation and anion column chromatography methods, as outlined previously

(45, 46). The CrVIO3-H2SO4 digestion method was employed as it has been shown to preferentially

liberate hydrogenous Re and Os yielding more accurate and precise age determinations (47, 48).

Total procedural blanks during this study were 88.0 ± 2.1 pg and 0.18 ± 0.07 pg for Re and Os

respectively, with an average 187Os/188Os value of 0.25 ± 0.05 (1σ, n = 4). The major source (>90%)

of Re blank is from the CrVIO3-H2SO4 solution.

Isotopic measurements were performed using a ThermoFisher TRITON PLUS thermal

ionization mass spectrometer in negative mode at the Yale University via static Faraday collection

for Re and ion-counting using a secondary electron multiplier in peak-hopping mode for Os (49,

50). The Os samples were loaded onto 99.995% Pt wire (H-Cross, NJ) in 9 N HBr and covered

with a saturated solution of Ba(OH)2 in 0.1 N NaOH as activator and analyzed as oxides of Os.

Interference of 187ReO3 on 187OsO3 was corrected by the measured intensity of 185ReO3. Mass

fractionation was corrected with 192Os/188Os = 3.0826, using the exponential fractional law.

Measurement quality was monitored by repeated measurement of the DROsS standard solution,

which yielded 187Os/188Os values of 0.16091 ± 0.00015 (n=51) over the course of the measurement

campaign, in good agreement with values obtained by other laboratories (51, 52). The Yale

University Re standard solution (measured on faraday cups during analytical sessions) yields an

average 185Re/187Re value of 0.59783 ± 0.0006; 1σ, n = 17), which is indistinguishable, within

uncertainty previously published values (53). The measured difference in 185Re/187Re values for

the Re solution and the accepted 185Re/187Re value of 0.59738; previously published values (53)

are used to correct the Re sample data for instrument mass fractionation and blank and spike

contributions.

Uncertainties for 187Re/188Os and 187Os/188Os are determined by error propagation of

uncertainties in Re and Os mass spectrometry measurements, blank abundances and isotopic

compositions, spike calibrations, and reproducibility of standard Re and Os isotopic values. The

Re-Os isotopic data, 2σ calculated uncertainties for 187Re/188Os and 187Os/188Os, and the associated

error correlation function (rho) are regressed to yield a Re-Os date using Isoplot V. 4.15 with the

λ 187Re constant of 1.666 x 10-11a-1 (54-56). Elemental concentrations and isotopic compositions

21

for the Re-Os geochronology samples are listed in Table S2. All samples display enrichments

above average crustal values with Re abundances ranging from 0.64 to 245.1 ng/g and Os

abundances from 56 to 4703 pg/g.

Carbon and Oxygen Isotope Geochemistry

Carbonate rock samples from northwestern Canada were analyzed at both Dartmouth College

and the Yale Analytical and Stable Isotope Center. 0.1-0.5 kg samples of limestone and dolostone

were collected approximately every m throughout detailed measured stratigraphic sections and

targeted to avoid obvious fracturing or veining. The samples were then slabbed perpendicular to

bedding using a lapidary saw and ~ 5-10 mg of powder was drilled from individual laminations

using a drill press with a dental carbide drill bit. Carbonate powders analyzed at Dartmouth College

(JB1704, J1711, JB1707, T1701, J1713, JB1801) were reacted with phosphoric acid (H3PO4) at

70°C on a Gasbench II preparation device attached to a ThermoFinnigan DeltaPlus XL continuous

flow isotope ratio mass spectrometer. δ13Ccarb and δ18Ocarb were measured simultaneously and

isotopic data are reported in standard delta notation as the per mil difference from VPDB (Vienna

Pee Dee Belemnite). Precision and accuracy were monitored by running a total of 12 standards for

every 76 samples using 11:3 sample/standard bracketing. The standard set includes two external

standards (NBS-18 and Elemental Microanalysis (EM) Carrara Marble), as well as an internal

marble standard. Samples are measured relative to an internal CO2 gas standard and then converted

to the VPDB scale using the known composition of NBS-18 (δ13C = -5.01; δ18O = -23.20) and the

EM-Carrara Marble (δ13Ccarb = 2.10; δ18Ocarb = -2.01). Measured precision was 0.1-0.15‰ (1σ) for

δ13Ccarb and 0.15-0.2‰ (1σ) for δ18Ocarb. Samples run at the Yale Analytical and Stable Isotopic

Center (J1719) followed an identical procedure using a KIEL carbonate preparation device

connected to a ThermoFinnigan MAT 253. The standard set includes the MERC (δ13C = -48.96;

δ18O = -16.48), PX (δ13Ccarb = 2.25; δ18Ocarb = -1.79), and YM (δ13Ccarb = -1.59; δ18Ocarb = -6.03)

standards which were calibrated against the NIBS 19, NBS 18, and LSVEC international standards

on the VPDB scale. Internal precision was reported as 0.1-0.15‰ (1σ) for δ13Ccarb and 0.1-0.15 ‰

(1σ) for δ18Ocarb.

22

Fig. S1: Geological map of Oman, modified after published work (15, 16). Approximate

locations of Wells L and M shown. Stratigraphic and chemostratigraphic overview of Wells L

and M, with sampled horizons indicated.

Fig. S2: Lithostratigraphic and chemostratigraphic data for well Thamoud-6 with stratigraphic

positions of samples from Well L and Well M shown. Formation boundaries follow Petroleum

Development Oman's 2019 revision of stratigraphy. Recovery from the Shuram Excursion

occurs within the Buah Fm.

Fig. S3: Geological map and detailed measured sections from Ediacaran strata in the Ogilvie and

Wernecke Mountains, Yukon, Canada. The inset map shows the location of the measured

sections in the main figure where NWT–Northwest Territories. Measured sections display main

lithofacies and carbon isotope chemostratigraphy of the Rackla Group modified following

published work (27, 28). The starred locations display the stratigraphic position of the sampled

horizons.

Table S1: δ13Ccarb isotope data were compiled from the literature from globally distributed

successions (57-61). Published geochronological constraints and δ13Ccarb chemostratigraphy were

used to develop an age model.

Table S2: Rhenium and Os elemental abundance and isotopic composition data for isochron

regressions. Uncertainties are given as 2σ for 187Re/188Os and 187Os/188Os and 192Os. The

uncertainty includes the 2σ uncertainty for mass spectrometer analysis plus uncertainties for Os

blank abundance and isotopic composition. (a) Rho is the associated error correlation (55). (b) Osi

= initial 187Os/188Os isotope ratio calculated at 578, 567, 575, 562 and 574 Ma.

Table S3: In addition to ages from this work, some ages used for the construction of Figure 3 are

from previously published work (17, 31, 62-66). Ages published before 2012 are as recalculated

(67); ages are color-coded to their region of origin. All uncertainties include relevant decay

constant uncertainties. The * indicates U-Pb zircon chemical abrasion isotope dilution thermal

ionization mass spectrometry (CA-ID-TIMS) age; †indicates U-Pb zircon Sensitive High-

23

Resolution Ion Microprobe (SHRIMP) age; ‡indicates Re-Os organic-rich rock age. Ages from

this study are bolded.

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0123456789

1011 1213

Dep

th (K

m)

++ ++

++

+ + ++ + + + + + + + + + + +

+

+

++ +

++++++

++

Khuff

Abu Mahara

Nafun

Ara

WESTERNMARGIN

SOUTH OMAN SALTBASIN

A A’

UNITED ARAB EMIRATES

500 KM

SAUDIARABIA

OMAN

AL HAJAR MOUNTAINS

CENTRAL OMAN HIGH

GULF OF OMAN

ARABIAN SEA

Muscat

Mirbat

SaihHatat

Maradi Fault

AL H

UQF

FAHUDSALT BASIN

Masirah

Jabal Al Akhdar

GHA

BA

SALT

BAINEast Oman

Ophiolite Complex

Semail OphiolitesHawasina

Jurassic to Cretaceous

Permian – Triassic

Precambrian – Palaeozoic

Oman Salt Basins

Crystalline Basement

Subsurface SamplesLEGEND

DEFOR M ATIO

N

WES

TER

N

S

A

A’

100 KM

N

OBD

UC

TED

Well M

Well L

� �� �� ������� �

� ���������� �

�������� �� � �

FRO

NT

??

?

?

Masirah Bay Fm

Khufai Fm

Shuram Fm

Buah Fm

Volcaniclastics

Ara Group

igneous and metamorphic

basement

volcanic/volcaniclastics

diamictite

dolomitelimestone

siltstone/sandstone

silicylite

Re-Os ORR age(this study)

δ13C-20‰ 10‰

Thamoud-6

562.7 ± 3.8 Ma (Well M)

578.2 ± 5.9 Ma (Well L)

3000

2500

2750

2250

dept

h (m

)

Shuram Carbon Isotope Excursion

Shee

pbed

For

mat

ion

Rac

kla

Gro

up

Rackla

300

400

100

200

R.T.

CoverShale/Siltstone

SandstoneConglomerate

Lime/Dolo Mudstone

Grainstone

Recrystallized

BoundstoneRudstone

600

700

500

900

1000

800

1200

1300

1100

1500

1600

1400

Nad

alee

n Fo

rmat

ion

Low

er

Car

bona

teH

eter

olith

ic M

embe

rU

pper

Car

bona

te M

embe

rBl

ack

Shal

e M

embe

rG

.S.

Gra

met

rail

Form

atio

nB

luef

low

er F

orm

atio

n

Low

er c

arbo

nate

Mid

dle

mem

ber

Upp

er m

embe

r

0 m

Nadaleen Type Section, Section G3, Section B1 (Moynihan et al., 2019)

-15 -10 -5 0 5 100

δ13Ccarb(‰)

~150 m of talus anddip slope to base of

Algae Formation

1700

300

400

100

200

600

700

500

900

1000

800

1200

1300

1100

1500

1600

1400

1700

HC

Shee

pbed

For

mat

ion

Rac

kla

Gro

up

300

400

100

200

0 m

CoverShale/Siltstone

SandstoneConglomerate

Lime/Dolo Mudstone

GrainstoneBoundstoneRudstone

600

500

Gam

etra

ilN

adal

een

Blu

eflo

wer

Risky

Raven-sthroat

-15 -10 -5 0 5 100

δ13Ccarb(‰)

Goz AJB1707, T1701, J1719, T1703, F848, F849 (Macdonald et al., 2013)

300

400

100

200

600

500

Hay

Cr.

Uni

t PH

3

Upp

er M

ount

Har

per G

roup

Tango Tarn

300

400

100

200

HC 0 m

CoverShale/Siltstone

SandstoneConglomerate

Lime/Dolo Mudstone

GrainstoneBoundstoneRudstoneRecrystallized

Uni

t PH

4

J1713, JB1801, JB1704, J1711, F838 (Macdonald et al., 2013)

-15 -10 -5 0 5 100

100

200

δ13Ccarb(‰)

300

400

top not exposed

undiff.

planar-laminatedsilty dolograinstoneripple cross-laminatedsilty dolograinstone

intraclast rudstone

sandstone

coverdomal stromatolite

boundstoneshale

concretionary dolo/limemudstone

siltstone

recrystallized dolostone

karst cavity

conglomerate

dolomudstone

dolograinstone

finely-laminated turbidites

sand-rich limestone

cleaved sandy siltstone

slump mass/chaotic interval

diamictite lime grainstone

LITHOFACIES

exposure surfaceRe-Os date (Ma)

trough cross-stratifiedsandstone

Tango Tarn Goz A

Rackla

Tango Tarn Goz A

Rackla

135°0'0"W

135°0'0"W

140°0'0"W

140°0'0"W

66°0'0"N

66°0'0"N

64°30'0"N

64°30'0"N

100km

USA

Canada

GreenlandAlaska

YUKON

Arctic Circle

United States

sample locations

major fault

Cambrian-DevonianProterozoic-TerreneuvianWindermere Supergroup

Hay Creek Group

Wernecke Supergroup (Paleoproterozoic)

Pinguicula Group (Meso-Neoproterozoic)

Mackenzie Mtns Supergroup(Tonian)

Rackla Group

Hyland Group

Mount Harper, Rapitan Groups

Proterozoic

Platformal carbonates

Basinal carbonates

Transitional platform - basin

Basinal siliciclastics

Undivided

¹ALASKA

NWT

YUKON

567.3 ± 3.0574.0 ± 4.7

575.0 ± 5.1

Region LocationStratigraphic Height

(Outcrop) (m)Depth (Drillcore)

(m) δ13Ccarb (‰) Source Unit Age* Note

*Ages in bold are tied directly to an age constraint or other assumption as detailed In the Note. Ages not in bold are interpolated between them.Oman Thamoud-6 core n/a 2074.00 2.23 Petroleum Development Oman Ara Group 537.73Oman Thamoud-6 core n/a 2075.00 1.88 Petroleum Development Oman Ara Group 537.79Oman Thamoud-6 core n/a 2078.00 -2.9 Petroleum Development Oman Ara Group 537.97Oman Thamoud-6 core n/a 2080.00 -2.69 Petroleum Development Oman Ara Group 538.08Oman Thamoud-6 core n/a 2080.00 -2.06 Petroleum Development Oman Ara Group 538.08Oman Thamoud-6 core n/a 2084.00 -2.68 Petroleum Development Oman Ara Group 538.32Oman Thamoud-6 core n/a 2085.00 -3.08 Petroleum Development Oman Ara Group 538.38Oman Thamoud-6 core n/a 2090.00 -3.07 Petroleum Development Oman Ara Group 538.67Oman Thamoud-6 core n/a 2090.00 -2.89 Petroleum Development Oman Ara Group 538.67Oman Thamoud-6 core n/a 2092.00 -2.75 Petroleum Development Oman Ara Group 538.78Oman Thamoud-6 core n/a 2100.00 -3.67 Petroleum Development Oman Ara Group 539.25Oman Thamoud-6 core n/a 2100.00 -3.53 Petroleum Development Oman Ara Group 539.25Oman Thamoud-6 core n/a 2104.00 -3.73 Petroleum Development Oman Ara Group 539.48Oman Thamoud-6 core n/a 2105.00 -2.85 Petroleum Development Oman Ara Group 539.54Oman Thamoud-6 core n/a 2110.00 -3.11 Petroleum Development Oman Ara Group 539.83Oman Thamoud-6 core n/a 2110.00 -3.09 Petroleum Development Oman Ara Group 539.83Oman Thamoud-6 core n/a 2115.00 -4.41 Petroleum Development Oman Ara Group 540.13Oman Thamoud-6 core n/a 2120.00 -2.86 Petroleum Development Oman Ara Group 540.42Oman Thamoud-6 core n/a 2120.00 -2.95 Petroleum Development Oman Ara Group 540.42Oman Thamoud-6 core n/a 2125.00 -3.78 Petroleum Development Oman Ara Group 540.71Oman Thamoud-6 core n/a 2130.00 1.8 Petroleum Development Oman Ara Group 541.00

Oman Thamoud-6 core n/a 2130.00 1.13 Petroleum Development Oman Ara Group 541.00

ID-TIMS U-Pb age on ash layer within A4C unit of Ara Group, sample BB-5, from Oman. Bowring et al. 2007. As recalculated in GTS 2012.

Oman Thamoud-6 core n/a 2135.00 1.21 Petroleum Development Oman Ara Group 541.29Oman Thamoud-6 core n/a 2140.00 1.45 Petroleum Development Oman Ara Group 541.58Oman Thamoud-6 core n/a 2140.00 1.73 Petroleum Development Oman Ara Group 541.58Oman Thamoud-6 core n/a 2145.00 1.47 Petroleum Development Oman Ara Group 541.88Oman Thamoud-6 core n/a 2150.00 1.42 Petroleum Development Oman Ara Group 542.17Oman Thamoud-6 core n/a 2150.00 1.87 Petroleum Development Oman Ara Group 542.17Oman Thamoud-6 core n/a 2155.00 2.15 Petroleum Development Oman Ara Group 542.46Oman Thamoud-6 core n/a 2158.00 1.16 Petroleum Development Oman Ara Group 542.63Oman Thamoud-6 core n/a 2160.00 3.02 Petroleum Development Oman Ara Group 542.75Oman Thamoud-6 core n/a 2160.00 2.66 Petroleum Development Oman Ara Group 542.75Oman Thamoud-6 core n/a 2165.00 3.22 Petroleum Development Oman Ara Group 543.04Oman Thamoud-6 core n/a 2170.00 2.65 Petroleum Development Oman Ara Group 543.33Oman Thamoud-6 core n/a 2170.00 2.75 Petroleum Development Oman Ara Group 543.33Oman Thamoud-6 core n/a 2174.00 1.73 Petroleum Development Oman Ara Group 543.57Oman Thamoud-6 core n/a 2175.00 2.35 Petroleum Development Oman Ara Group 543.63Oman Thamoud-6 core n/a 2180.00 2.35 Petroleum Development Oman Ara Group 543.92Oman Thamoud-6 core n/a 2180.00 2.6 Petroleum Development Oman Ara Group 543.92Oman Thamoud-6 core n/a 2185.00 0.17 Petroleum Development Oman Ara Group 544.21Oman Thamoud-6 core n/a 2189.00 0.98 Petroleum Development Oman Ara Group 544.44Oman Thamoud-6 core n/a 2190.00 -0.24 Petroleum Development Oman Ara Group 544.50Oman Thamoud-6 core n/a 2190.00 -0.21 Petroleum Development Oman Ara Group 544.50Oman Thamoud-6 core n/a 2195.00 0.66 Petroleum Development Oman Ara Group 544.79Oman Thamoud-6 core n/a 2200.00 1.77 Petroleum Development Oman Ara Group 545.08Oman Thamoud-6 core n/a 2200.00 1.59 Petroleum Development Oman Ara Group 545.08Oman Thamoud-6 core n/a 2205.00 1.73 Petroleum Development Oman Ara Group 545.37Oman Thamoud-6 core n/a 2210.00 1.87 Petroleum Development Oman Ara Group 545.67Oman Thamoud-6 core n/a 2210.00 1.71 Petroleum Development Oman Ara Group 545.67Oman Thamoud-6 core n/a 2215.00 1.6 Petroleum Development Oman Ara Group 545.96Oman Thamoud-6 core n/a 2220.00 1.46 Petroleum Development Oman Ara Group 546.25Oman Thamoud-6 core n/a 2220.00 1.84 Petroleum Development Oman Ara Group 546.25Oman Thamoud-6 core n/a 2225.00 1.36 Petroleum Development Oman Ara Group 546.54Oman Thamoud-6 core n/a 2230.00 -1.04 Petroleum Development Oman Ara Group 546.83Oman Thamoud-6 core n/a 2230.00 1.61 Petroleum Development Oman Ara Group 546.83Oman Thamoud-6 core n/a 2235.00 -4.67 Petroleum Development Oman Ara Group 547.12Oman Thamoud-6 core n/a 2240.00 0.17 Petroleum Development Oman Ara Group 547.42Oman Thamoud-6 core n/a 2240.00 0.17 Petroleum Development Oman Ara Group 547.42Oman Thamoud-6 core n/a 2245.00 0.34 Petroleum Development Oman Ara Group 547.71Oman Thamoud-6 core n/a 2250.00 0.96 Petroleum Development Oman Ara Group 548.00

Oman Thamoud-6 core n/a 2250.00 0.19 Petroleum Development Oman Ara Group 548Estimated age of Buah-Ara unconformity, after Bowring et al. 2007.

Oman Thamoud-6 core n/a 2255.00 1.47 Petroleum Development Oman Volcaniclastics 548.14Oman Thamoud-6 core n/a 2255.00 1.27 Petroleum Development Oman Volcaniclastics 548.14Oman Thamoud-6 core n/a 2260.00 0.98 Petroleum Development Oman Volcaniclastics 548.28Oman Thamoud-6 core n/a 2260.00 0.87 Petroleum Development Oman Volcaniclastics 548.28Oman Thamoud-6 core n/a 2260.00 1.01 Petroleum Development Oman Volcaniclastics 548.28Oman Thamoud-6 core n/a 2265.00 0.23 Petroleum Development Oman Volcaniclastics 548.42Oman Thamoud-6 core n/a 2265.00 0.59 Petroleum Development Oman Volcaniclastics 548.42Oman Thamoud-6 core n/a 2270.00 -0.54 Petroleum Development Oman Volcaniclastics 548.56Oman Thamoud-6 core n/a 2270.00 -0.39 Petroleum Development Oman Volcaniclastics 548.56Oman Thamoud-6 core n/a 2275.00 0 Petroleum Development Oman Volcaniclastics 548.70Oman Thamoud-6 core n/a 2280.00 -0.13 Petroleum Development Oman Volcaniclastics 548.84Oman Thamoud-6 core n/a 2280.00 0.03 Petroleum Development Oman Volcaniclastics 548.84Oman Thamoud-6 core n/a 2285.00 -2.02 Petroleum Development Oman Volcaniclastics 548.98Oman Thamoud-6 core n/a 2290.00 -1.69 Petroleum Development Oman Volcaniclastics 549.12Oman Thamoud-6 core n/a 2290.00 -2.54 Petroleum Development Oman Volcaniclastics 549.12Oman Thamoud-6 core n/a 2290.00 -1.01 Petroleum Development Oman Volcaniclastics 549.12Oman Thamoud-6 core n/a 2295.00 -3.44 Petroleum Development Oman Volcaniclastics 549.26Oman Thamoud-6 core n/a 2300.00 -1.11 Petroleum Development Oman Volcaniclastics 549.40Oman Thamoud-6 core n/a 2300.00 -0.89 Petroleum Development Oman Volcaniclastics 549.40Oman Thamoud-6 core n/a 2305.00 -1.95 Petroleum Development Oman Volcaniclastics 549.55Oman Thamoud-6 core n/a 2305.00 -3.83 Petroleum Development Oman Volcaniclastics 549.55Oman Thamoud-6 core n/a 2310.00 -1.77 Petroleum Development Oman Volcaniclastics 549.69Oman Thamoud-6 core n/a 2310.00 -1.27 Petroleum Development Oman Volcaniclastics 549.69Oman Thamoud-6 core n/a 2315.00 -1.09 Petroleum Development Oman Volcaniclastics 549.83Oman Thamoud-6 core n/a 2320.00 -1.23 Petroleum Development Oman Volcaniclastics 549.97Oman Thamoud-6 core n/a 2320.00 -1.3 Petroleum Development Oman Volcaniclastics 549.97Oman Thamoud-6 core n/a 2325.00 -0.19 Petroleum Development Oman Volcaniclastics 550.11Oman Thamoud-6 core n/a 2330.00 -0.19 Petroleum Development Oman Volcaniclastics 550.25Oman Thamoud-6 core n/a 2330.00 -0.84 Petroleum Development Oman Volcaniclastics 550.25Oman Thamoud-6 core n/a 2335.00 -0.85 Petroleum Development Oman Volcaniclastics 550.39Oman Thamoud-6 core n/a 2340.00 -0.78 Petroleum Development Oman Volcaniclastics 550.53Oman Thamoud-6 core n/a 2340.00 -0.92 Petroleum Development Oman Volcaniclastics 550.53Oman Thamoud-6 core n/a 2350.00 -5.61 Petroleum Development Oman Volcaniclastics 550.81Oman Thamoud-6 core n/a 2350.00 -4.69 Petroleum Development Oman Volcaniclastics 550.81Oman Thamoud-6 core n/a 2355.00 -5.21 Petroleum Development Oman Volcaniclastics 550.95

Oman Thamoud-6 core n/a 2360.00 -1.92 Petroleum Development Oman Buah Fm 551.09

ID-TIMS U-Pb date on ash layer in Doushantuo Fm, China. Condon et al. 2005. Associated with δ13C values ~0 permil, above Shuram Excursion; sequence boundary between age and excursion in Doushantuo stratigraphy. Correlated on the basis of chemostratigraphy. As recalculated in GTS 2012.

Oman Thamoud-6 core n/a 2361.00 -6.03 Petroleum Development Oman Buah Fm 551.42Oman Thamoud-6 core n/a 2365.00 -1.73 Petroleum Development Oman Buah Fm 552.75Oman Thamoud-6 core n/a 2369.00 -0.73 Petroleum Development Oman Buah Fm 554.08Oman Thamoud-6 core n/a 2370.00 -3.25 Petroleum Development Oman Buah Fm 554.41Oman Thamoud-6 core n/a 2370.00 -2.57 Petroleum Development Oman Buah Fm 554.41Oman Thamoud-6 core n/a 2380.00 -5.27 Petroleum Development Oman Buah Fm 557.72Oman Thamoud-6 core n/a 2380.00 -5.02 Petroleum Development Oman Buah Fm 557.72Oman Thamoud-6 core n/a 2390.00 -3.51 Petroleum Development Oman Buah Fm 561.04

Oman Thamoud-6 core n/a 2395.00 -0.47 Petroleum Development Oman Buah Fm 562.7

Well M sample, middle Buah Fm, Oman, this study. Sample Overlies Shuram excursion; associated with positive δ13C values.

Oman Thamoud-6 core n/a 2395.00 -0.64 Petroleum Development Oman Buah Fm 562.70Oman Thamoud-6 core n/a 2400.00 -0.19 Petroleum Development Oman Buah Fm 562.78Oman Thamoud-6 core n/a 2400.00 -0.52 Petroleum Development Oman Buah Fm 562.78Oman Thamoud-6 core n/a 2410.00 -1.96 Petroleum Development Oman Buah Fm 562.93Oman Thamoud-6 core n/a 2410.00 -2.33 Petroleum Development Oman Buah Fm 562.93Oman Thamoud-6 core n/a 2415.00 -2 Petroleum Development Oman Buah Fm 563.00Oman Thamoud-6 core n/a 2420.00 -2.74 Petroleum Development Oman Buah Fm 563.08Oman Thamoud-6 core n/a 2420.00 -2.37 Petroleum Development Oman Buah Fm 563.08Oman Thamoud-6 core n/a 2425.00 -2.49 Petroleum Development Oman Buah Fm 563.15Oman Thamoud-6 core n/a 2430.00 -3.2 Petroleum Development Oman Buah Fm 563.23Oman Thamoud-6 core n/a 2440.00 -1.74 Petroleum Development Oman Buah Fm 563.38Oman Thamoud-6 core n/a 2460.00 -1.55 Petroleum Development Oman Buah Fm 563.68Oman Thamoud-6 core n/a 2480.00 -2.22 Petroleum Development Oman Buah Fm 563.98Oman Thamoud-6 core n/a 2495.00 -3.73 Petroleum Development Oman Buah Fm 564.21Oman Thamoud-6 core n/a 2505.00 -3.42 Petroleum Development Oman Buah Fm 564.36Oman Thamoud-6 core n/a 2520.00 -3.03 Petroleum Development Oman Buah Fm 564.59Oman Thamoud-6 core n/a 2530.00 -2.97 Petroleum Development Oman Buah Fm 564.74Oman Thamoud-6 core n/a 2540.00 -3.42 Petroleum Development Oman Buah Fm 564.89Oman Thamoud-6 core n/a 2560.00 -3.37 Petroleum Development Oman Buah Fm 565.19Oman Thamoud-6 core n/a 2580.00 -2.55 Petroleum Development Oman Buah Fm 565.49Oman Thamoud-6 core n/a 2600.00 -4.11 Petroleum Development Oman Buah Fm 565.79Oman Thamoud-6 core n/a 2620.00 -4.17 Petroleum Development Oman Buah Fm 566.09Oman Thamoud-6 core n/a 2640.00 -3.03 Petroleum Development Oman Buah Fm 566.40Oman Thamoud-6 core n/a 2660.00 -2.71 Petroleum Development Oman Buah Fm 566.70Oman Thamoud-6 core n/a 2680.00 -2.71 Petroleum Development Oman Buah Fm 567.00

Oman Thamoud-6 core n/a 2700.00 -2.8 Petroleum Development Oman Buah Fm 567.3

Sample A1707, Blueflower Fm, NW Canada, this study. Lies 16 m above the contact with the underlying Gametrail Fm. Coal Creek location; lies in +2 permille plateau above a carbonate gap. Correlated to Oman on the basis of chemostratigraphy.

Oman Thamoud-6 core n/a 2710.00 -3.03 Petroleum Development Oman Buah Fm 567.86Oman Thamoud-6 core n/a 2730.00 -2.74 Petroleum Development Oman Buah Fm 568.98Oman Thamoud-6 core n/a 2735 -3.48 Petroleum Development Oman Buah Fm 569.25Oman Thamoud-6 core n/a 2740 -8.83 Petroleum Development Oman Buah Fm 569.53Oman Thamoud-6 core n/a 2745 -6.94 Petroleum Development Oman Shuram Fm 569.81Oman Thamoud-6 core n/a 2745 -8.16 Petroleum Development Oman Shuram Fm 569.81Oman Thamoud-6 core n/a 2750 -7.34 Petroleum Development Oman Shuram Fm 570.09Oman Thamoud-6 core n/a 2750 -8.02 Petroleum Development Oman Shuram Fm 570.09Oman Thamoud-6 core n/a 2752 -7.58 Petroleum Development Oman Shuram Fm 570.20Oman Thamoud-6 core n/a 2755 -8.28 Petroleum Development Oman Shuram Fm 570.37Oman Thamoud-6 core n/a 2760 -7.72 Petroleum Development Oman Shuram Fm 570.65Oman Thamoud-6 core n/a 2760 -8.27 Petroleum Development Oman Shuram Fm 570.65Oman Thamoud-6 core n/a 2765 -8.31 Petroleum Development Oman Shuram Fm 570.93Oman Thamoud-6 core n/a 2770 -8.18 Petroleum Development Oman Shuram Fm 571.21Oman Thamoud-6 core n/a 2770 -8.49 Petroleum Development Oman Shuram Fm 571.21Oman Thamoud-6 core n/a 2775 -8.92 Petroleum Development Oman Shuram Fm 571.49Oman Thamoud-6 core n/a 2780 -9.6 Petroleum Development Oman Shuram Fm 571.77Oman Thamoud-6 core n/a 2780 -10.28 Petroleum Development Oman Shuram Fm 571.77Oman Thamoud-6 core n/a 2785 -10.31 Petroleum Development Oman Shuram Fm 572.05Oman Thamoud-6 core n/a 2790 -11.53 Petroleum Development Oman Shuram Fm 572.33Oman Thamoud-6 core n/a 2790 -11.75 Petroleum Development Oman Shuram Fm 572.33Oman Thamoud-6 core n/a 2795 -12.75 Petroleum Development Oman Shuram Fm 572.60Oman Thamoud-6 core n/a 2800 -10.78 Petroleum Development Oman Khufai Fm 572.88Oman Thamoud-6 core n/a 2800 -11.28 Petroleum Development Oman Khufai Fm 572.88Oman Thamoud-6 core n/a 2805 -7 Petroleum Development Oman Khufai Fm 573.16Oman Thamoud-6 core n/a 2810 -6.61 Petroleum Development Oman Khufai Fm 573.44Oman Thamoud-6 core n/a 2810 -6.33 Petroleum Development Oman Khufai Fm 573.44

Table S1 Carbon Isotope Data

Oman Thamoud-6 core n/a 2815 -3.36 Petroleum Development Oman Khufai Fm 573.72

Oman Thamoud-6 core n/a 2820 1.67 Petroleum Development Oman Khufai Fm 574

Sample J1719, Nadaleen Fm, NW Canada. Underlies Shuram excursion. Occurs within a plateau δ13C values of +8 permille about 30 meters below contact with the Gametrail. Correlated to Oman on the basis of chemostratigraphy.

Oman Thamoud-6 core n/a 2820 2.2 Petroleum Development Oman Khufai Fm 574.00Oman Thamoud-6 core n/a 2825 3.35 Petroleum Development Oman Khufai Fm 574.26Oman Thamoud-6 core n/a 2830 2.52 Petroleum Development Oman Khufai Fm 574.53Oman Thamoud-6 core n/a 2830 3.29 Petroleum Development Oman Khufai Fm 574.53Oman Thamoud-6 core n/a 2840 3.39 Petroleum Development Oman Khufai Fm 575.05Oman Thamoud-6 core n/a 2840 4.42 Petroleum Development Oman Khufai Fm 575.05Oman Thamoud-6 core n/a 2844 4.7 Petroleum Development Oman Khufai Fm 575.26Oman Thamoud-6 core n/a 2845 4.3 Petroleum Development Oman Khufai Fm 575.31Oman Thamoud-6 core n/a 2850 3.93 Petroleum Development Oman Khufai Fm 575.58Oman Thamoud-6 core n/a 2850 4.57 Petroleum Development Oman Khufai Fm 575.58Oman Thamoud-6 core n/a 2855 4.62 Petroleum Development Oman Khufai Fm 575.84Oman Thamoud-6 core n/a 2858 4.96 Petroleum Development Oman Khufai Fm 576.00Oman Thamoud-6 core n/a 2860 4.4 Petroleum Development Oman Khufai Fm 576.10Oman Thamoud-6 core n/a 2860 4.5 Petroleum Development Oman Khufai Fm 576.10Oman Thamoud-6 core n/a 2865 5.13 Petroleum Development Oman Khufai Fm 576.36Oman Thamoud-6 core n/a 2867 3.98 Petroleum Development Oman Khufai Fm 576.47Oman Thamoud-6 core n/a 2870 4.68 Petroleum Development Oman Khufai Fm 576.63Oman Thamoud-6 core n/a 2870 4.72 Petroleum Development Oman Khufai Fm 576.63Oman Thamoud-6 core n/a 2872 4.76 Petroleum Development Oman Khufai Fm 576.73Oman Thamoud-6 core n/a 2875 4.54 Petroleum Development Oman Khufai Fm 576.89Oman Thamoud-6 core n/a 2877 4.27 Petroleum Development Oman Khufai Fm 576.99Oman Thamoud-6 core n/a 2880 4.61 Petroleum Development Oman Khufai Fm 577.15Oman Thamoud-6 core n/a 2890 3.86 Petroleum Development Oman Khufai Fm 577.68

Oman Thamoud-6 core n/a 2900 Petroleum Development Oman basal Khufai Fm 578.2Well L sample, basal Khufai Fm, Oman. This study. Underlies Shuram excursion.

Northwest Canada Redstone section 0.0 n/a -1.9 James et al. 2001 Ravensthroat Fm 635.3

ID-TIMS U-Pb date on ash layer in Doushantuo Fm, China. Condon et al. 2005. Correlated to the Northwest Canada cap carbonate. As recalculated in GTS 2012.

Northwest Canada Redstone section 0.0 n/a -0.7 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 0.1 n/a -1.7 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 0.2 n/a -1.9 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 0.5 n/a -2.3 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 0.7 n/a -2.0 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 1.0 n/a -2.6 James et al. 2001 Ravensthroat Fm 635.3Northwest Canada Redstone section 1.5 n/a -3.0 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.0 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.0 n/a -2.6 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.2 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.3 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.4 n/a -2.6 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 2.5 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 3.0 n/a -2.9 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 3.0 n/a -2.5 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 3.5 n/a -3.1 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 3.8 n/a -2.6 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 4.0 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 4.5 n/a -2.9 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 5.0 n/a -2.9 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 5.5 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 5.8 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 6.5 n/a -2.5 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 6.8 n/a -2.7 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 7.8 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 8.8 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 9.8 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 11.0 n/a -2.9 James et al. 2001 Ravensthroat Fm 635.2Northwest Canada Redstone section 12.0 n/a -3.1 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 13.0 n/a -3.0 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 13.8 n/a -3.2 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 14.0 n/a -3.2 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 14.7 n/a -3.2 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 14.7 n/a -2.6 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 15.8 n/a -2.8 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 16.0 n/a -3.6 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 16.0 n/a -1.4 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 17.0 n/a -3.5 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 17.0 n/a -4.6 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 17.0 n/a -4.4 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 17.0 n/a -4.5 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 17.7 n/a -3.5 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 18.0 n/a -3.7 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 18.0 n/a -3.9 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 18.8 n/a -5.5 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 19.2 n/a -4.1 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 19.2 n/a -5.5 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 20.0 n/a -5.2 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 21.0 n/a -5.2 James et al. 2001 Ravensthroat Fm 635.1Northwest Canada Redstone section 22.0 n/a -5.4 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 22.7 n/a -4.1 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 23.0 n/a -5.1 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 23.8 n/a -4.9 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 24.0 n/a -5.4 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 24.8 n/a -4.6 James et al. 2001 Ravensthroat Fm 635.0Northwest Canada Redstone section 26.7 n/a -3.6 James et al. 2001 Ravensthroat Fm 635.0 Estimated end of cap carbonate deposition.

Northwest Canada Nadaleen Type Section 121.50 n/a 7.31 Moynihan et al. 2019 Nadaleen Fm 595.0Estimated start of Nadaleen Fm deposition on the basis of chemostratigraphic correlation.

Northwest Canada Nadaleen Type Section 122.40 n/a 8.51 Moynihan et al. 2019 Nadaleen Fm 595.0Northwest Canada Nadaleen Type Section 123.00 n/a 8.39 Moynihan et al. 2019 Nadaleen Fm 594.9Northwest Canada Nadaleen Type Section 125.00 n/a 8.2 Moynihan et al. 2019 Nadaleen Fm 594.8Northwest Canada Nadaleen Type Section 136.80 n/a 5.48 Moynihan et al. 2019 Nadaleen Fm 594.2Northwest Canada Nadaleen Type Section 144.80 n/a 8 Moynihan et al. 2019 Nadaleen Fm 593.8Northwest Canada Nadaleen Type Section 148.50 n/a 8.36 Moynihan et al. 2019 Nadaleen Fm 593.6Northwest Canada Nadaleen Type Section 155.80 n/a 8.27 Moynihan et al. 2019 Nadaleen Fm 593.3Northwest Canada Nadaleen Type Section 158.00 n/a 8.37 Moynihan et al. 2019 Nadaleen Fm 593.2Northwest Canada Nadaleen Type Section 162.00 n/a 8.53 Moynihan et al. 2019 Nadaleen Fm 593.0Northwest Canada Nadaleen Type Section 165.10 n/a 8.48 Moynihan et al. 2019 Nadaleen Fm 592.8Northwest Canada Nadaleen Type Section 169.40 n/a 8.36 Moynihan et al. 2019 Nadaleen Fm 592.6Northwest Canada Nadaleen Type Section 173.60 n/a 8.44 Moynihan et al. 2019 Nadaleen Fm 592.4Northwest Canada Nadaleen Type Section 177.80 n/a 8.55 Moynihan et al. 2019 Nadaleen Fm 592.2Northwest Canada Nadaleen Type Section 183.20 n/a 8.41 Moynihan et al. 2019 Nadaleen Fm 591.9Northwest Canada Nadaleen Type Section 192.80 n/a 7.57 Moynihan et al. 2019 Nadaleen Fm 591.4Northwest Canada Nadaleen Type Section 195.20 n/a 8.17 Moynihan et al. 2019 Nadaleen Fm 591.3Northwest Canada Nadaleen Type Section 199.60 n/a 8.13 Moynihan et al. 2019 Nadaleen Fm 591.1Northwest Canada Nadaleen Type Section 204.70 n/a 8.48 Moynihan et al. 2019 Nadaleen Fm 590.8Northwest Canada Nadaleen Type Section 207.90 n/a 8.6 Moynihan et al. 2019 Nadaleen Fm 590.6Northwest Canada Nadaleen Type Section 210.50 n/a 8.03 Moynihan et al. 2019 Nadaleen Fm 590.5Northwest Canada Nadaleen Type Section 217.50 n/a 9.21 Moynihan et al. 2019 Nadaleen Fm 590.1Northwest Canada Nadaleen Type Section 222.10 n/a 9.33 Moynihan et al. 2019 Nadaleen Fm 589.9Northwest Canada Nadaleen Type Section 227.50 n/a 9.45 Moynihan et al. 2019 Nadaleen Fm 589.6Northwest Canada Nadaleen Type Section 234.60 n/a 9.37 Moynihan et al. 2019 Nadaleen Fm 589.3Northwest Canada Nadaleen Type Section 300.20 n/a 8.26 Moynihan et al. 2019 Nadaleen Fm 586.0Northwest Canada Nadaleen Type Section 302.50 n/a 7.69 Moynihan et al. 2019 Nadaleen Fm 585.8Northwest Canada Nadaleen Type Section 304.60 n/a 8.17 Moynihan et al. 2019 Nadaleen Fm 585.7Northwest Canada Nadaleen Type Section 435.50 n/a 9.03 Moynihan et al. 2019 Nadaleen Fm 579.1Northwest Canada Nadaleen Type Section 436.50 n/a 9.43 Moynihan et al. 2019 Nadaleen Fm 579.1Northwest Canada Nadaleen Type Section 438.10 n/a 9.58 Moynihan et al. 2019 Nadaleen Fm 579.0Northwest Canada Nadaleen Type Section 441.10 n/a 9.46 Moynihan et al. 2019 Nadaleen Fm 578.8Northwest Canada Nadaleen Type Section 446.60 n/a 9.16 Moynihan et al. 2019 Nadaleen Fm 578.6Northwest Canada Nadaleen Type Section 449.20 n/a 9.18 Moynihan et al. 2019 Nadaleen Fm 578.4Northwest Canada Nadaleen Type Section 451.60 n/a 9.29 Moynihan et al. 2019 Nadaleen Fm 578.3Northwest Canada Nadaleen Type Section 454.80 n/a 9.31 Moynihan et al. 2019 Nadaleen Fm 578.2Northwest Canada Nadaleen Type Section 457.10 n/a 9.33 Moynihan et al. 2019 Nadaleen Fm 578.0Northwest Canada Nadaleen Type Section 460.00 n/a 9.38 Moynihan et al. 2019 Nadaleen Fm 577.9Northwest Canada Nadaleen Type Section 462.40 n/a 9.3 Moynihan et al. 2019 Nadaleen Fm 577.8Northwest Canada Nadaleen Type Section 477.80 n/a 10.89 Moynihan et al. 2019 Nadaleen Fm 577.0Northwest Canada Nadaleen Type Section 479.70 n/a 9.53 Moynihan et al. 2019 Nadaleen Fm 576.9Northwest Canada Nadaleen Type Section 481.70 n/a 9.54 Moynihan et al. 2019 Nadaleen Fm 576.8Northwest Canada Nadaleen Type Section 484.20 n/a 10.03 Moynihan et al. 2019 Nadaleen Fm 576.7Northwest Canada Nadaleen Type Section 486.10 n/a 9.82 Moynihan et al. 2019 Nadaleen Fm 576.6Northwest Canada Nadaleen Type Section 488.80 n/a 10.38 Moynihan et al. 2019 Nadaleen Fm 576.4Northwest Canada Nadaleen Type Section 489.80 n/a 9.7 Moynihan et al. 2019 Nadaleen Fm 576.4Northwest Canada Nadaleen Type Section 491.30 n/a 10.04 Moynihan et al. 2019 Nadaleen Fm 576.3Northwest Canada Nadaleen Type Section 493.20 n/a 10.56 Moynihan et al. 2019 Nadaleen Fm 576.2Northwest Canada Nadaleen Type Section 495.20 n/a 11.4 Moynihan et al. 2019 Nadaleen Fm 576.1Northwest Canada Nadaleen Type Section 496.30 n/a 10.86 Moynihan et al. 2019 Nadaleen Fm 576.1Northwest Canada Nadaleen Type Section 499.20 n/a 11.26 Moynihan et al. 2019 Nadaleen Fm 575.9Northwest Canada Nadaleen Type Section 504.70 n/a 10.69 Moynihan et al. 2019 Nadaleen Fm 575.6Northwest Canada Nadaleen Type Section 508.80 n/a 11.38 Moynihan et al. 2019 Nadaleen Fm 575.4Northwest Canada Nadaleen Type Section 510.60 n/a 5.04 Moynihan et al. 2019 Nadaleen Fm 575.3Northwest Canada Nadaleen Type Section 513.50 n/a 9.69 Moynihan et al. 2019 Nadaleen Fm 575.2Northwest Canada Nadaleen Type Section 515.20 n/a 9.26 Moynihan et al. 2019 Nadaleen Fm 575.1Northwest Canada Nadaleen Type Section 521.10 n/a 9.38 Moynihan et al. 2019 Nadaleen Fm 574.8Northwest Canada Nadaleen Type Section 523.40 n/a 9.11 Moynihan et al. 2019 Nadaleen Fm 574.7Northwest Canada Nadaleen Type Section 525.50 n/a 8.33 Moynihan et al. 2019 Nadaleen Fm 574.6Northwest Canada Nadaleen Type Section 527.50 n/a 9.22 Moynihan et al. 2019 Nadaleen Fm 574.5Northwest Canada Nadaleen Type Section 529.50 n/a 9.73 Moynihan et al. 2019 Nadaleen Fm 574.4Northwest Canada Nadaleen Type Section 531.70 n/a 9.41 Moynihan et al. 2019 Nadaleen Fm 574.3Northwest Canada Nadaleen Type Section 533.50 n/a 9.39 Moynihan et al. 2019 Nadaleen Fm 574.2

Northwest Canada Nadaleen Type Section 536.90 n/a 9.2 Moynihan et al. 2019 Nadaleen Fm 574.0

Sample J1719, Nadaleen Fm, NW Canada, this study. Underlies Shuram excursion. Occurs within a plateau of positive δ13C values about 30 meters below contact with the Gametrail.

Northwest Canada Nadaleen Type Section 539.00 n/a 9.69 Moynihan et al. 2019 Nadaleen Fm 573.9Northwest Canada Nadaleen Type Section 541.00 n/a 9.61 Moynihan et al. 2019 Nadaleen Fm 573.9Northwest Canada Nadaleen Type Section 544.00 n/a 10.4 Moynihan et al. 2019 Nadaleen Fm 573.8Northwest Canada Nadaleen Type Section 547.00 n/a 8.69 Moynihan et al. 2019 Nadaleen Fm 573.7Northwest Canada Nadaleen Type Section 549.50 n/a 8.64 Moynihan et al. 2019 Nadaleen Fm 573.6Northwest Canada Nadaleen Type Section 552.70 n/a 8.59 Moynihan et al. 2019 Nadaleen Fm 573.5Northwest Canada Nadaleen Type Section 558.00 n/a 8.55 Moynihan et al. 2019 Nadaleen Fm 573.4Northwest Canada Nadaleen Type Section 560.00 n/a 7.97 Moynihan et al. 2019 Nadaleen Fm 573.3Northwest Canada Nadaleen Type Section 564.00 n/a 7.36 Moynihan et al. 2019 Nadaleen Fm 573.2Northwest Canada Nadaleen Type Section 566.00 n/a 6.96 Moynihan et al. 2019 Nadaleen Fm 573.1Northwest Canada Gametrail G3 Section 0.60 n/a -12.67 Moynihan et al. 2019 Gametrail Fm 573.1Northwest Canada Gametrail G3 Section 3.10 n/a -11.19 Moynihan et al. 2019 Gametrail Fm 573.1Northwest Canada Gametrail G3 Section 4.40 n/a -12.19 Moynihan et al. 2019 Gametrail Fm 573.0Northwest Canada Gametrail G3 Section 9.70 n/a -11.76 Moynihan et al. 2019 Gametrail Fm 572.9Northwest Canada Gametrail G3 Section 10.70 n/a -11.26 Moynihan et al. 2019 Gametrail Fm 572.8Northwest Canada Gametrail G3 Section 12.60 n/a -10.38 Moynihan et al. 2019 Gametrail Fm 572.8Northwest Canada Gametrail G3 Section 14.90 n/a -11.79 Moynihan et al. 2019 Gametrail Fm 572.7Northwest Canada Gametrail G3 Section 16.40 n/a -11.87 Moynihan et al. 2019 Gametrail Fm 572.7Northwest Canada Gametrail G3 Section 19.00 n/a -10.52 Moynihan et al. 2019 Gametrail Fm 572.6Northwest Canada Gametrail G3 Section 98.70 n/a -9.79 Moynihan et al. 2019 Gametrail Fm 570.3Northwest Canada Gametrail G3 Section 99.20 n/a -10.03 Moynihan et al. 2019 Gametrail Fm 570.2Northwest Canada Gametrail G3 Section 100.70 n/a -10.14 Moynihan et al. 2019 Gametrail Fm 570.2

Northwest Canada Gametrail G3 Section 101.30 n/a -9.79 Moynihan et al. 2019 Gametrail Fm 570.2Northwest Canada Gametrail G3 Section 108.90 n/a -9.6 Moynihan et al. 2019 Gametrail Fm 570.0Northwest Canada Gametrail G3 Section 112.10 n/a -9.02 Moynihan et al. 2019 Gametrail Fm 569.9Northwest Canada Gametrail G3 Section 113.10 n/a -9.25 Moynihan et al. 2019 Gametrail Fm 569.8Northwest Canada Gametrail G3 Section 114.20 n/a -9.12 Moynihan et al. 2019 Gametrail Fm 569.8Northwest Canada Gametrail G3 Section 115.30 n/a -8.43 Moynihan et al. 2019 Gametrail Fm 569.8Northwest Canada Gametrail G3 Section 117.00 n/a -9.17 Moynihan et al. 2019 Gametrail Fm 569.7Northwest Canada Gametrail G3 Section 118.20 n/a -8.92 Moynihan et al. 2019 Gametrail Fm 569.7Northwest Canada Gametrail G3 Section 133.90 n/a -8.87 Moynihan et al. 2019 Gametrail Fm 569.2Northwest Canada Gametrail G3 Section 134.30 n/a -8.36 Moynihan et al. 2019 Gametrail Fm 569.2Northwest Canada Gametrail G3 Section 137.80 n/a -8.9 Moynihan et al. 2019 Gametrail Fm 569.1Northwest Canada Gametrail G3 Section 138.60 n/a -9 Moynihan et al. 2019 Gametrail Fm 569.1Northwest Canada Gametrail G3 Section 139.70 n/a -8.85 Moynihan et al. 2019 Gametrail Fm 569.1Northwest Canada Gametrail G3 Section 143.90 n/a -8.97 Moynihan et al. 2019 Gametrail Fm 568.9Northwest Canada Gametrail G3 Section 144.80 n/a -8.81 Moynihan et al. 2019 Gametrail Fm 568.9Northwest Canada Gametrail G3 Section 146.70 n/a -8.4 Moynihan et al. 2019 Gametrail Fm 568.9Northwest Canada Gametrail G3 Section 147.80 n/a -8.17 Moynihan et al. 2019 Gametrail Fm 568.8Northwest Canada Gametrail G3 Section 149.00 n/a -8.25 Moynihan et al. 2019 Gametrail Fm 568.8Northwest Canada Gametrail G3 Section 150.90 n/a -8.35 Moynihan et al. 2019 Gametrail Fm 568.7Northwest Canada Gametrail G3 Section 151.80 n/a -8.53 Moynihan et al. 2019 Gametrail Fm 568.7Northwest Canada Gametrail G3 Section 160.20 n/a -8.96 Moynihan et al. 2019 Gametrail Fm 568.5Northwest Canada Gametrail G3 Section 163.80 n/a -8.69 Moynihan et al. 2019 Gametrail Fm 568.4Northwest Canada Gametrail G3 Section 164.70 n/a -7.62 Moynihan et al. 2019 Gametrail Fm 568.3Northwest Canada Gametrail G3 Section 165.60 n/a -8.16 Moynihan et al. 2019 Gametrail Fm 568.3Northwest Canada Gametrail G3 Section 166.80 n/a -8.04 Moynihan et al. 2019 Gametrail Fm 568.3Northwest Canada Gametrail G3 Section 169.90 n/a -8.32 Moynihan et al. 2019 Gametrail Fm 568.2Northwest Canada Gametrail G3 Section 170.20 n/a -8.59 Moynihan et al. 2019 Gametrail Fm 568.2Northwest Canada Gametrail G3 Section 172.30 n/a -8.41 Moynihan et al. 2019 Gametrail Fm 568.1Northwest Canada Gametrail G3 Section 174.40 n/a -8.28 Moynihan et al. 2019 Gametrail Fm 568.1Northwest Canada Gametrail G3 Section 176.50 n/a -7.91 Moynihan et al. 2019 Gametrail Fm 568.0Northwest Canada Gametrail G3 Section 178.70 n/a -6.79 Moynihan et al. 2019 Gametrail Fm 567.9Northwest Canada Gametrail G3 Section 181.00 n/a -5.29 Moynihan et al. 2019 Gametrail Fm 567.9Northwest Canada Gametrail G3 Section 183.00 n/a -2.67 Moynihan et al. 2019 Gametrail Fm 567.8Northwest Canada Blueflower G3 Section 185.70 n/a 1.94 Moynihan et al. 2019 Blueflower Fm 567.7Northwest Canada Blueflower G3 Section 187.80 n/a 3.4 Moynihan et al. 2019 Blueflower Fm 567.7Northwest Canada Blueflower G3 Section 189.70 n/a 2.25 Moynihan et al. 2019 Blueflower Fm 567.6Northwest Canada Blueflower G3 Section 193.00 n/a 1.98 Moynihan et al. 2019 Blueflower Fm 567.5Northwest Canada Blueflower G3 Section 195.10 n/a 1.94 Moynihan et al. 2019 Blueflower Fm 567.4Northwest Canada Blueflower G3 Section 196.80 n/a 1.01 Moynihan et al. 2019 Blueflower Fm 567.4Northwest Canada Blueflower G3 Section 198.90 n/a 0.6 Moynihan et al. 2019 Blueflower Fm 567.3

Northwest Canada Blueflower G3 Section 200.10 n/a 1.52 Moynihan et al. 2019 Blueflower Fm 567.3

Sample A1707, Blueflower Fm, NW Canad, this study. Lies 16 m above the contact with the underlying Gametrail Fm. Coal Creek location; lies in +2 permille plateau above a carbonate gap.

Northwest Canada Blueflower G3 Section 209.40 n/a 1.01 Moynihan et al. 2019 Blueflower Fm 566.1Northwest Canada Blueflower G3 Section 211.60 n/a 0.78 Moynihan et al. 2019 Blueflower Fm 565.8Northwest Canada Blueflower G3 Section 214.50 n/a 1.01 Moynihan et al. 2019 Blueflower Fm 565.5Northwest Canada Blueflower G3 Section 216.50 n/a 0.67 Moynihan et al. 2019 Blueflower Fm 565.2Northwest Canada Blueflower G3 Section 219.20 n/a 0.45 Moynihan et al. 2019 Blueflower Fm 564.9Northwest Canada Blueflower G3 Section 221.10 n/a 0.95 Moynihan et al. 2019 Blueflower Fm 564.6Northwest Canada Blueflower G3 Section 223.30 n/a 1.56 Moynihan et al. 2019 Blueflower Fm 564.3Northwest Canada Blueflower G3 Section 225.40 n/a 0.66 Moynihan et al. 2019 Blueflower Fm 564.1Northwest Canada Blueflower G3 Section 227.20 n/a 0.37 Moynihan et al. 2019 Blueflower Fm 563.8Northwest Canada Blueflower G3 Section 229.30 n/a 0.78 Moynihan et al. 2019 Blueflower Fm 563.6Northwest Canada Blueflower G3 Section 231.40 n/a 1.78 Moynihan et al. 2019 Blueflower Fm 563.3Northwest Canada Blueflower G3 Section 235.40 n/a 0.97 Moynihan et al. 2019 Blueflower Fm 562.8Northwest Canada Blueflower G3 Section 237.30 n/a 0.32 Moynihan et al. 2019 Blueflower Fm 562.5Northwest Canada Blueflower G3 Section 239.30 n/a 1.29 Moynihan et al. 2019 Blueflower Fm 562.3Northwest Canada Blueflower G3 Section 241.30 n/a 1.39 Moynihan et al. 2019 Blueflower Fm 562.0Northwest Canada Blueflower G3 Section 243.10 n/a 1.46 Moynihan et al. 2019 Blueflower Fm 561.8Northwest Canada Blueflower G3 Section 245.50 n/a 1.25 Moynihan et al. 2019 Blueflower Fm 561.5Northwest Canada Blueflower G3 Section 247.40 n/a 1.16 Moynihan et al. 2019 Blueflower Fm 561.3Northwest Canada Blueflower G3 Section 249.70 n/a 1.19 Moynihan et al. 2019 Blueflower Fm 561.0Northwest Canada Blueflower G3 Section 251.80 n/a 1.07 Moynihan et al. 2019 Blueflower Fm 560.7Northwest Canada Blueflower G3 Section 255.80 n/a 0.56 Moynihan et al. 2019 Blueflower Fm 560.2

Northwest Canada Blueflower G3 Section 257.20 n/a -0.47 Moynihan et al. 2019 Blueflower Fm 560.0Estimated end of Blueflower Fm deposition on the basis of chemostratigraphy.

Northwest Canada Algae/Risky A2 Section 1.10 n/a 3.3 Moynihan et al. 2019 Algae/Risky Fm 550.0Estimated start of Algae/Risky Fm deposition on the basis of chemostratigraphy.

Northwest Canada Algae/Risky A2 Section 1.40 n/a 3.48 Moynihan et al. 2019 Algae/Risky Fm 550.0Northwest Canada Algae/Risky A2 Section 3.30 n/a 3.16 Moynihan et al. 2019 Algae/Risky Fm 549.9Northwest Canada Algae/Risky A2 Section 4.20 n/a 2.87 Moynihan et al. 2019 Algae/Risky Fm 549.8Northwest Canada Algae/Risky A2 Section 5.00 n/a 3.43 Moynihan et al. 2019 Algae/Risky Fm 549.8Northwest Canada Algae/Risky A2 Section 6.70 n/a 3.19 Moynihan et al. 2019 Algae/Risky Fm 549.7Northwest Canada Algae/Risky A2 Section 7.10 n/a 2.9 Moynihan et al. 2019 Algae/Risky Fm 549.7Northwest Canada Algae/Risky A2 Section 8.80 n/a 2.99 Moynihan et al. 2019 Algae/Risky Fm 549.6Northwest Canada Algae/Risky A2 Section 9.90 n/a 3.2 Moynihan et al. 2019 Algae/Risky Fm 549.5Northwest Canada Algae/Risky A2 Section 11.00 n/a 2.87 Moynihan et al. 2019 Algae/Risky Fm 549.4Northwest Canada Algae/Risky A2 Section 12.90 n/a 3.16 Moynihan et al. 2019 Algae/Risky Fm 549.3Northwest Canada Algae/Risky A2 Section 15.10 n/a 3.08 Moynihan et al. 2019 Algae/Risky Fm 549.2Northwest Canada Algae/Risky A2 Section 16.00 n/a 2.81 Moynihan et al. 2019 Algae/Risky Fm 549.2Northwest Canada Algae/Risky A2 Section 18.20 n/a 2.78 Moynihan et al. 2019 Algae/Risky Fm 549.0Northwest Canada Algae/Risky A2 Section 20.80 n/a 2.54 Moynihan et al. 2019 Algae/Risky Fm 548.9Northwest Canada Algae/Risky A2 Section 22.80 n/a 2.28 Moynihan et al. 2019 Algae/Risky Fm 548.8Northwest Canada Algae/Risky A2 Section 26.30 n/a 1.61 Moynihan et al. 2019 Algae/Risky Fm 548.6Northwest Canada Algae/Risky A2 Section 29.40 n/a 0.13 Moynihan et al. 2019 Algae/Risky Fm 548.4Northwest Canada Algae/Risky A2 Section 37.50 n/a 2.34 Moynihan et al. 2019 Algae/Risky Fm 547.9Northwest Canada Algae/Risky A2 Section 39.50 n/a 2.33 Moynihan et al. 2019 Algae/Risky Fm 547.8Northwest Canada Algae/Risky A2 Section 41.70 n/a 2.5 Moynihan et al. 2019 Algae/Risky Fm 547.7Northwest Canada Algae/Risky A2 Section 43.30 n/a 2.3 Moynihan et al. 2019 Algae/Risky Fm 547.6Northwest Canada Algae/Risky A2 Section 44.60 n/a 2.68 Moynihan et al. 2019 Algae/Risky Fm 547.5Northwest Canada Algae/Risky A2 Section 47.70 n/a 2.2 Moynihan et al. 2019 Algae/Risky Fm 547.3Northwest Canada Algae/Risky A2 Section 48.90 n/a 2.07 Moynihan et al. 2019 Algae/Risky Fm 547.3Northwest Canada Algae/Risky A2 Section 49.80 n/a 2.16 Moynihan et al. 2019 Algae/Risky Fm 547.2Northwest Canada Algae/Risky A2 Section 52.30 n/a 1.62 Moynihan et al. 2019 Algae/Risky Fm 547.1Northwest Canada Algae/Risky A2 Section 53.40 n/a 1.42 Moynihan et al. 2019 Algae/Risky Fm 547.0Northwest Canada Algae/Risky A2 Section 54.30 n/a 2.07 Moynihan et al. 2019 Algae/Risky Fm 547.0Northwest Canada Algae/Risky A2 Section 56.10 n/a 1.31 Moynihan et al. 2019 Algae/Risky Fm 546.9Northwest Canada Algae/Risky A2 Section 57.30 n/a 2.31 Moynihan et al. 2019 Algae/Risky Fm 546.8Northwest Canada Algae/Risky A2 Section 59.40 n/a 2.56 Moynihan et al. 2019 Algae/Risky Fm 546.7Northwest Canada Algae/Risky A2 Section 61.80 n/a 4.09 Moynihan et al. 2019 Algae/Risky Fm 546.5Northwest Canada Algae/Risky A2 Section 63.60 n/a 4.38 Moynihan et al. 2019 Algae/Risky Fm 546.4Northwest Canada Algae/Risky A2 Section 64.60 n/a 5.36 Moynihan et al. 2019 Algae/Risky Fm 546.4Northwest Canada Algae/Risky A2 Section 66.80 n/a 5.86 Moynihan et al. 2019 Algae/Risky Fm 546.3Northwest Canada Algae/Risky A2 Section 68.90 n/a 5.29 Moynihan et al. 2019 Algae/Risky Fm 546.1Northwest Canada Algae/Risky A2 Section 69.70 n/a 5.73 Moynihan et al. 2019 Algae/Risky Fm 546.1Northwest Canada Algae/Risky A2 Section 71.00 n/a 5.48 Moynihan et al. 2019 Algae/Risky Fm 546.0Northwest Canada Algae/Risky A2 Section 71.70 n/a 4.81 Moynihan et al. 2019 Algae/Risky Fm 546.0Northwest Canada Algae/Risky A2 Section 73.20 n/a 5.12 Moynihan et al. 2019 Algae/Risky Fm 545.9Northwest Canada Algae/Risky A2 Section 74.50 n/a 4.88 Moynihan et al. 2019 Algae/Risky Fm 545.8Northwest Canada Algae/Risky A2 Section 76.30 n/a 3.85 Moynihan et al. 2019 Algae/Risky Fm 545.7Northwest Canada Algae/Risky A2 Section 77.50 n/a 3.99 Moynihan et al. 2019 Algae/Risky Fm 545.7Northwest Canada Algae/Risky A2 Section 78.70 n/a 3.98 Moynihan et al. 2019 Algae/Risky Fm 545.6Northwest Canada Algae/Risky A2 Section 79.90 n/a 3.8 Moynihan et al. 2019 Algae/Risky Fm 545.5Northwest Canada Algae/Risky A2 Section 91.20 n/a 3.55 Moynihan et al. 2019 Algae/Risky Fm 544.9Northwest Canada Algae/Risky A2 Section 92.10 n/a 3.82 Moynihan et al. 2019 Algae/Risky Fm 544.8Northwest Canada Algae/Risky A2 Section 93.40 n/a 3.64 Moynihan et al. 2019 Algae/Risky Fm 544.8Northwest Canada Algae/Risky A2 Section 94.70 n/a 4.3 Moynihan et al. 2019 Algae/Risky Fm 544.7Northwest Canada Algae/Risky A2 Section 95.70 n/a 3.97 Moynihan et al. 2019 Algae/Risky Fm 544.6Northwest Canada Algae/Risky A2 Section 97.50 n/a 4.57 Moynihan et al. 2019 Algae/Risky Fm 544.5Northwest Canada Algae/Risky A2 Section 98.30 n/a 4.51 Moynihan et al. 2019 Algae/Risky Fm 544.5Northwest Canada Algae/Risky A2 Section 99.70 n/a 3.71 Moynihan et al. 2019 Algae/Risky Fm 544.4Northwest Canada Algae/Risky A2 Section 103.40 n/a 2.47 Moynihan et al. 2019 Algae/Risky Fm 544.2Northwest Canada Algae/Risky A2 Section 104.30 n/a 1.88 Moynihan et al. 2019 Algae/Risky Fm 544.1Northwest Canada Algae/Risky A2 Section 105.40 n/a 1.64 Moynihan et al. 2019 Algae/Risky Fm 544.1Northwest Canada Algae/Risky A2 Section 108.20 n/a 1.94 Moynihan et al. 2019 Algae/Risky Fm 543.9Northwest Canada Algae/Risky A2 Section 110.10 n/a 2.15 Moynihan et al. 2019 Algae/Risky Fm 543.8Northwest Canada Algae/Risky A2 Section 110.80 n/a 1.81 Moynihan et al. 2019 Algae/Risky Fm 543.8Northwest Canada Algae/Risky A2 Section 112.10 n/a 2.05 Moynihan et al. 2019 Algae/Risky Fm 543.7Northwest Canada Algae/Risky A2 Section 113.00 n/a 2.25 Moynihan et al. 2019 Algae/Risky Fm 543.6Northwest Canada Algae/Risky A2 Section 115.80 n/a 2.34 Moynihan et al. 2019 Algae/Risky Fm 543.5Northwest Canada Algae/Risky A2 Section 116.80 n/a 3.19 Moynihan et al. 2019 Algae/Risky Fm 543.4Northwest Canada Algae/Risky A2 Section 118.10 n/a 2.31 Moynihan et al. 2019 Algae/Risky Fm 543.3Northwest Canada Algae/Risky A2 Section 120.20 n/a 2.62 Moynihan et al. 2019 Algae/Risky Fm 543.2Northwest Canada Algae/Risky A2 Section 122.20 n/a 2.13 Moynihan et al. 2019 Algae/Risky Fm 543.1Northwest Canada Algae/Risky A2 Section 123.10 n/a 1.26 Moynihan et al. 2019 Algae/Risky Fm 543.1Northwest Canada Algae/Risky A2 Section 125.80 n/a 0.62 Moynihan et al. 2019 Algae/Risky Fm 542.9Northwest Canada Algae/Risky A2 Section 128.70 n/a 2.09 Moynihan et al. 2019 Algae/Risky Fm 542.7Northwest Canada Algae/Risky A2 Section 129.60 n/a 2.05 Moynihan et al. 2019 Algae/Risky Fm 542.7Northwest Canada Algae/Risky A2 Section 131.10 n/a 2.16 Moynihan et al. 2019 Algae/Risky Fm 542.6Northwest Canada Algae/Risky A2 Section 132.70 n/a 1.69 Moynihan et al. 2019 Algae/Risky Fm 542.5Northwest Canada Algae/Risky A2 Section 133.90 n/a 1.91 Moynihan et al. 2019 Algae/Risky Fm 542.4Northwest Canada Algae/Risky A2 Section 137.00 n/a 1.9 Moynihan et al. 2019 Algae/Risky Fm 542.3Northwest Canada Algae/Risky A2 Section 139.20 n/a 1.87 Moynihan et al. 2019 Algae/Risky Fm 542.1Northwest Canada Algae/Risky A2 Section 140.30 n/a 1.66 Moynihan et al. 2019 Algae/Risky Fm 542.1Northwest Canada Algae/Risky A2 Section 143.40 n/a 2.13 Moynihan et al. 2019 Algae/Risky Fm 541.9Northwest Canada Algae/Risky A2 Section 147.00 n/a 2.15 Moynihan et al. 2019 Algae/Risky Fm 541.7Northwest Canada Algae/Risky A2 Section 148.10 n/a 2.13 Moynihan et al. 2019 Algae/Risky Fm 541.6Northwest Canada Algae/Risky A2 Section 150.30 n/a 2.01 Moynihan et al. 2019 Algae/Risky Fm 541.5Northwest Canada Algae/Risky A2 Section 152.40 n/a 2.23 Moynihan et al. 2019 Algae/Risky Fm 541.4Northwest Canada Algae/Risky A2 Section 154.60 n/a 2.02 Moynihan et al. 2019 Algae/Risky Fm 541.3Northwest Canada Algae/Risky A2 Section 156.60 n/a 2.47 Moynihan et al. 2019 Algae/Risky Fm 541.2Northwest Canada Algae/Risky A2 Section 159.70 n/a 2.48 Moynihan et al. 2019 Algae/Risky Fm 541.0Northwest Canada Algae/Risky A2 Section 161.80 n/a 2.17 Moynihan et al. 2019 Algae/Risky Fm 540.9Northwest Canada Algae/Risky A2 Section 163.90 n/a 2.43 Moynihan et al. 2019 Algae/Risky Fm 540.7Northwest Canada Algae/Risky A2 Section 166.10 n/a 2.11 Moynihan et al. 2019 Algae/Risky Fm 540.6Northwest Canada Algae/Risky A2 Section 169.20 n/a 1.11 Moynihan et al. 2019 Algae/Risky Fm 540.4Northwest Canada Algae/Risky A2 Section 170.20 n/a 1.98 Moynihan et al. 2019 Algae/Risky Fm 540.4Northwest Canada Algae/Risky A2 Section 173.00 n/a 1.73 Moynihan et al. 2019 Algae/Risky Fm 540.2Northwest Canada Algae/Risky A2 Section 175.60 n/a 2.1 Moynihan et al. 2019 Algae/Risky Fm 540.1Northwest Canada Algae/Risky A2 Section 177.00 n/a 1.4 Moynihan et al. 2019 Algae/Risky Fm 540.0Northwest Canada Algae/Risky A2 Section 179.30 n/a 1.83 Moynihan et al. 2019 Algae/Risky Fm 539.9Northwest Canada Algae/Risky A2 Section 182.10 n/a 1.66 Moynihan et al. 2019 Algae/Risky Fm 539.7Northwest Canada Algae/Risky A2 Section 183.40 n/a 1.51 Moynihan et al. 2019 Algae/Risky Fm 539.6Northwest Canada Algae/Risky A2 Section 184.20 n/a 1.27 Moynihan et al. 2019 Algae/Risky Fm 539.6Northwest Canada Algae/Risky A2 Section 186.20 n/a 1.27 Moynihan et al. 2019 Algae/Risky Fm 539.5Northwest Canada Algae/Risky A2 Section 187.00 n/a 0.89 Moynihan et al. 2019 Algae/Risky Fm 539.4Northwest Canada Algae/Risky A2 Section 187.40 n/a 1.21 Moynihan et al. 2019 Algae/Risky Fm 539.4Northwest Canada Algae/Risky A2 Section 188.90 n/a 0.97 Moynihan et al. 2019 Algae/Risky Fm 539.3Northwest Canada Algae/Risky A2 Section 189.10 n/a 1.35 Moynihan et al. 2019 Algae/Risky Fm 539.3Northwest Canada Algae/Risky A2 Section 189.90 n/a 0.83 Moynihan et al. 2019 Algae/Risky Fm 539.3Northwest Canada Algae/Risky A2 Section 190.80 n/a 0.15 Moynihan et al. 2019 Algae/Risky Fm 539.2Northwest Canada Algae/Risky A2 Section 195.20 n/a 0.04 Moynihan et al. 2019 Algae/Risky Fm 539.0Northwest Canada Algae/Risky A2 Section 196.30 n/a 0.05 Moynihan et al. 2019 Algae/Risky Fm 538.9Northwest Canada Algae/Risky A2 Section 197.70 n/a -0.26 Moynihan et al. 2019 Algae/Risky Fm 538.8

Northwest Canada Algae/Risky A2 Section 199.80 n/a 0.08 Moynihan et al. 2019 Algae/Risky Fm 538.7

Precambrian-Cambrian boundary. Age after Linnemann et al. 2018, a combined paleontological study + ID-TIMS U-Pb ash dates on Swartpunt section, Namibia, suggest moving the Precambrian-Cambrian boundary younger, between 538.8 and 538.6 Ma.

China Drill core n/a 35.6 1.87 Tahata et al. 2013 Dengying Fm 547.29

Tied to age model below built from Jiang et al. 2007 data for boundary of Shibantan and Hamajin members.

China Drill core n/a 36.08 -0.32 Tahata et al. 2013 Dengying Fm 547.38China Drill core n/a 41.06 1.15 Tahata et al. 2013 Dengying Fm 548.33China Drill core n/a 41.15 1.7 Tahata et al. 2013 Dengying Fm 548.35China Drill core n/a 41.2 1.5 Tahata et al. 2013 Dengying Fm 548.36China Drill core n/a 41.21 2.87 Tahata et al. 2013 Dengying Fm 548.36China Drill core n/a 41.25 1.77 Tahata et al. 2013 Dengying Fm 548.37China Drill core n/a 41.28 2.53 Tahata et al. 2013 Dengying Fm 548.37China Drill core n/a 44.67 1.66 Tahata et al. 2013 Dengying Fm 549.02China Drill core n/a 46.05 2.82 Tahata et al. 2013 Dengying Fm 549.28China Drill core n/a 49.61 1.83 Tahata et al. 2013 Dengying Fm 549.96China Drill core n/a 50.6 1.21 Tahata et al. 2013 Dengying Fm 550.15China Drill core n/a 52.61 1.64 Tahata et al. 2013 Dengying Fm 550.53China Drill core n/a 52.92 1.4 Tahata et al. 2013 Dengying Fm 550.59China Drill core n/a 53 0.74 Tahata et al. 2013 Dengying Fm 550.60China Drill core n/a 54.6 -0.34 Tahata et al. 2013 Dengying Fm 550.91China Drill core n/a 54.76 -1.05 Tahata et al. 2013 Dengying Fm 550.94China Drill core n/a 55.34 -0.84 Tahata et al. 2013 Dengying Fm 551.05China Drill core n/a 55.47 -0.66 Tahata et al. 2013 Dengying Fm 551.07

China Drill core n/a 55.56 -3.05 Tahata et al. 2013 Doushantuo Fm (Member IV) 551.09

ID-TIMS U-Pb date on ash layer in Doushantuo Fm, China. Associated with δ13C values ~0 permil, above Shuram Excursion; sequence boundary between age and excursion in stratigraphy. Condon et al. 2005. As recalculated in GTS 2012.

China Drill core n/a 58.59 -5.05 Tahata et al. 2013 Doushantuo Fm (Member IV) 560.27

China Drill core n/a 60.91 -4.38 Tahata et al. 2013 Doushantuo Fm (Member IV) 567.3

Sample A1707, Blueflower Fm, NW Canada. Lies 16 m above the contact with the underlying Gametrail Fm. Coal Creek location; lies in +2 permille plateau above a carbonate gap. Correlated to China on the basis of chemostratigraphy (return to less negative δ13C values) and existing age contraints.

China Drill core n/a 62.4 -7.27 Tahata et al. 2013 Doushantuo Fm (Member III) 567.53China Drill core n/a 62.48 -3.89 Tahata et al. 2013 Doushantuo Fm (Member III) 567.54China Drill core n/a 64.11 -7.81 Tahata et al. 2013 Doushantuo Fm (Member III) 567.79China Drill core n/a 68.54 -7.68 Tahata et al. 2013 Doushantuo Fm (Member III) 568.47China Drill core n/a 72.2 -6.43 Tahata et al. 2013 Doushantuo Fm (Member III) 569.03China Drill core n/a 72.39 -7.87 Tahata et al. 2013 Doushantuo Fm (Member III) 569.06China Drill core n/a 73.87 -7.93 Tahata et al. 2013 Doushantuo Fm (Member III) 569.29China Drill core n/a 73.95 -6.66 Tahata et al. 2013 Doushantuo Fm (Member III) 569.30China Drill core n/a 75.4 -8.17 Tahata et al. 2013 Doushantuo Fm (Member III) 569.52China Drill core n/a 75.86 -6.82 Tahata et al. 2013 Doushantuo Fm (Member III) 569.59China Drill core n/a 75.9 -8.19 Tahata et al. 2013 Doushantuo Fm (Member III) 569.60China Drill core n/a 78.22 -7.57 Tahata et al. 2013 Doushantuo Fm (Member III) 569.95China Drill core n/a 80.92 -8.11 Tahata et al. 2013 Doushantuo Fm (Member III) 570.37China Drill core n/a 81.07 -6.96 Tahata et al. 2013 Doushantuo Fm (Member III) 570.39China Drill core n/a 84.17 -7.99 Tahata et al. 2013 Doushantuo Fm (Member III) 570.86China Drill core n/a 87.23 -8.07 Tahata et al. 2013 Doushantuo Fm (Member III) 571.33China Drill core n/a 87.38 -8.04 Tahata et al. 2013 Doushantuo Fm (Member III) 571.36China Drill core n/a 89.35 -8.9 Tahata et al. 2013 Doushantuo Fm (Member III) 571.66China Drill core n/a 89.97 -8.71 Tahata et al. 2013 Doushantuo Fm (Member III) 571.75China Drill core n/a 91.1 -8.99 Tahata et al. 2013 Doushantuo Fm (Member III) 571.93China Drill core n/a 92.4 -8.82 Tahata et al. 2013 Doushantuo Fm (Member III) 572.13China Drill core n/a 92.53 -9.12 Tahata et al. 2013 Doushantuo Fm (Member III) 572.15China Drill core n/a 93.65 -8.94 Tahata et al. 2013 Doushantuo Fm (Member III) 572.32China Drill core n/a 94.81 -9 Tahata et al. 2013 Doushantuo Fm (Member III) 572.50China Drill core n/a 95.95 -8.48 Tahata et al. 2013 Doushantuo Fm (Member III) 572.67China Drill core n/a 96.44 -7.78 Tahata et al. 2013 Doushantuo Fm (Member III) 572.74China Drill core n/a 97.19 -8.38 Tahata et al. 2013 Doushantuo Fm (Member III) 572.86China Drill core n/a 97.33 -8.39 Tahata et al. 2013 Doushantuo Fm (Member III) 572.88China Drill core n/a 97.47 -8.17 Tahata et al. 2013 Doushantuo Fm (Member III) 572.90China Drill core n/a 97.79 -7.76 Tahata et al. 2013 Doushantuo Fm (Member III) 572.95China Drill core n/a 97.94 -8.11 Tahata et al. 2013 Doushantuo Fm (Member III) 572.97China Drill core n/a 98.19 -7.99 Tahata et al. 2013 Doushantuo Fm (Member III) 573.01China Drill core n/a 98.48 -8.3 Tahata et al. 2013 Doushantuo Fm (Member III) 573.06China Drill core n/a 98.65 -8.56 Tahata et al. 2013 Doushantuo Fm (Member III) 573.08China Drill core n/a 98.67 -8.67 Tahata et al. 2013 Doushantuo Fm (Member III) 573.09China Drill core n/a 99 -8.14 Tahata et al. 2013 Doushantuo Fm (Member III) 573.14China Drill core n/a 99.26 -7.73 Tahata et al. 2013 Doushantuo Fm (Member III) 573.18China Drill core n/a 99.55 -7.56 Tahata et al. 2013 Doushantuo Fm (Member III) 573.22China Drill core n/a 99.72 -7.37 Tahata et al. 2013 Doushantuo Fm (Member III) 573.25China Drill core n/a 99.85 -7.21 Tahata et al. 2013 Doushantuo Fm (Member III) 573.27China Drill core n/a 100.05 -7.15 Tahata et al. 2013 Doushantuo Fm (Member III) 573.30China Drill core n/a 100.13 -6.78 Tahata et al. 2013 Doushantuo Fm (Member III) 573.31China Drill core n/a 100.27 -6.75 Tahata et al. 2013 Doushantuo Fm (Member III) 573.33China Drill core n/a 100.43 -6.65 Tahata et al. 2013 Doushantuo Fm (Member III) 573.36China Drill core n/a 100.52 -6.48 Tahata et al. 2013 Doushantuo Fm (Member III) 573.37China Drill core n/a 100.65 -6.3 Tahata et al. 2013 Doushantuo Fm (Member III) 573.39China Drill core n/a 100.8 -7.32 Tahata et al. 2013 Doushantuo Fm (Member III) 573.41China Drill core n/a 100.99 -7.28 Tahata et al. 2013 Doushantuo Fm (Member III) 573.44China Drill core n/a 101.13 -6.58 Tahata et al. 2013 Doushantuo Fm (Member III) 573.46China Drill core n/a 101.38 -5.97 Tahata et al. 2013 Doushantuo Fm (Member III) 573.50China Drill core n/a 101.5 -5.7 Tahata et al. 2013 Doushantuo Fm (Member III) 573.52China Drill core n/a 101.67 -5.95 Tahata et al. 2013 Doushantuo Fm (Member III) 573.55China Drill core n/a 101.89 -5.52 Tahata et al. 2013 Doushantuo Fm (Member III) 573.58China Drill core n/a 102.01 -5.25 Tahata et al. 2013 Doushantuo Fm (Member III) 573.60China Drill core n/a 102.09 -4.99 Tahata et al. 2013 Doushantuo Fm (Member III) 573.61China Drill core n/a 102.17 -4.89 Tahata et al. 2013 Doushantuo Fm (Member III) 573.62China Drill core n/a 102.32 -4.37 Tahata et al. 2013 Doushantuo Fm (Member III) 573.65China Drill core n/a 102.54 -4.1 Tahata et al. 2013 Doushantuo Fm (Member III) 573.68China Drill core n/a 104.06 -0.31 Tahata et al. 2013 Doushantuo Fm (Member III) 573.91

China Drill core n/a 104.63 -0.27 Tahata et al. 2013 Doushantuo Fm (Member III) 574

Sample J1719, Nadaleen Fm, NW Canada, this study. Underlies Shuram excursion. Correlated to China on the basis of chemostratigraphy.

China Drill core n/a 105.91 0.65 Tahata et al. 2013 Doushantuo Fm (Member III) 574.95China Drill core n/a 107.4 0.93 Tahata et al. 2013 Doushantuo Fm (Member III) 576.07China Drill core n/a 108.12 0.95 Tahata et al. 2013 Doushantuo Fm (Member III) 576.60China Drill core n/a 109.54 2.31 Tahata et al. 2013 Doushantuo Fm (Member III) 577.66China Drill core n/a 109.67 3.14 Tahata et al. 2013 Doushantuo Fm (Member III) 577.76China Drill core n/a 109.97 3.05 Tahata et al. 2013 Doushantuo Fm (Member III) 577.98China Drill core n/a 111.54 4.34 Tahata et al. 2013 Doushantuo Fm (Member III) 579.15China Drill core n/a 111.83 4.09 Tahata et al. 2013 Doushantuo Fm (Member III) 579.37China Drill core n/a 112.53 4.47 Tahata et al. 2013 Doushantuo Fm (Member III) 579.89China Drill core n/a 112.56 4.39 Tahata et al. 2013 Doushantuo Fm (Member III) 579.91China Drill core n/a 112.76 4.38 Tahata et al. 2013 Doushantuo Fm (Member III) 580.06China Drill core n/a 112.9 4.42 Tahata et al. 2013 Doushantuo Fm (Member III) 580.17China Drill core n/a 113.57 4.83 Tahata et al. 2013 Doushantuo Fm (Member III) 580.67China Drill core n/a 114 4.62 Tahata et al. 2013 Doushantuo Fm (Member III) 580.99China Drill core n/a 114.18 4.42 Tahata et al. 2013 Doushantuo Fm (Member III) 581.12China Drill core n/a 114.49 4.84 Tahata et al. 2013 Doushantuo Fm (Member III) 581.35China Drill core n/a 114.58 4.11 Tahata et al. 2013 Doushantuo Fm (Member III) 581.42China Drill core n/a 114.81 4.83 Tahata et al. 2013 Doushantuo Fm (Member III) 581.59China Drill core n/a 114.97 4.76 Tahata et al. 2013 Doushantuo Fm (Member III) 581.71China Drill core n/a 115.11 4.54 Tahata et al. 2013 Doushantuo Fm (Member III) 581.82China Drill core n/a 115.22 4.92 Tahata et al. 2013 Doushantuo Fm (Member III) 581.90China Drill core n/a 115.39 4.96 Tahata et al. 2013 Doushantuo Fm (Member III) 582.03China Drill core n/a 115.58 4.4 Tahata et al. 2013 Doushantuo Fm (Member III) 582.17China Drill core n/a 115.63 4.73 Tahata et al. 2013 Doushantuo Fm (Member III) 582.20China Drill core n/a 115.84 4.34 Tahata et al. 2013 Doushantuo Fm (Member III) 582.36China Drill core n/a 116.21 4.58 Tahata et al. 2013 Doushantuo Fm (Member III) 582.64China Drill core n/a 116.43 4.4 Tahata et al. 2013 Doushantuo Fm (Member III) 582.80China Drill core n/a 116.62 4.31 Tahata et al. 2013 Doushantuo Fm (Member III) 582.94China Drill core n/a 116.76 4.15 Tahata et al. 2013 Doushantuo Fm (Member III) 583.05China Drill core n/a 116.87 4.27 Tahata et al. 2013 Doushantuo Fm (Member III) 583.13China Drill core n/a 117.02 5.45 Tahata et al. 2013 Doushantuo Fm (Member III) 583.24China Drill core n/a 117.21 5.15 Tahata et al. 2013 Doushantuo Fm (Member III) 583.38China Drill core n/a 117.34 5.45 Tahata et al. 2013 Doushantuo Fm (Member III) 583.48China Drill core n/a 117.93 4.88 Tahata et al. 2013 Doushantuo Fm (Member III) 583.92China Drill core n/a 118.03 5.11 Tahata et al. 2013 Doushantuo Fm (Member III) 583.99China Drill core n/a 118.24 5.12 Tahata et al. 2013 Doushantuo Fm (Member III) 584.15China Drill core n/a 118.4 5.24 Tahata et al. 2013 Doushantuo Fm (Member III) 584.27China Drill core n/a 118.54 5.05 Tahata et al. 2013 Doushantuo Fm (Member III) 584.37China Drill core n/a 118.66 4.98 Tahata et al. 2013 Doushantuo Fm (Member III) 584.46China Drill core n/a 118.84 4.89 Tahata et al. 2013 Doushantuo Fm (Member III) 584.60China Drill core n/a 119.08 5.21 Tahata et al. 2013 Doushantuo Fm (Member III) 584.78China Drill core n/a 119.49 5.22 Tahata et al. 2013 Doushantuo Fm (Member III) 585.08China Drill core n/a 119.63 5.08 Tahata et al. 2013 Doushantuo Fm (Member III) 585.19China Drill core n/a 119.75 4.95 Tahata et al. 2013 Doushantuo Fm (Member III) 585.28China Drill core n/a 119.99 5.01 Tahata et al. 2013 Doushantuo Fm (Member III) 585.46China Drill core n/a 120.17 4.72 Tahata et al. 2013 Doushantuo Fm (Member III) 585.59China Drill core n/a 120.42 4.81 Tahata et al. 2013 Doushantuo Fm (Member III) 585.78China Drill core n/a 120.57 4.61 Tahata et al. 2013 Doushantuo Fm (Member III) 585.89China Drill core n/a 120.76 4.93 Tahata et al. 2013 Doushantuo Fm (Member III) 586.03China Drill core n/a 121.81 4.87 Tahata et al. 2013 Doushantuo Fm (Member III) 586.81China Drill core n/a 122.28 4.52 Tahata et al. 2013 Doushantuo Fm (Member III) 587.16China Drill core n/a 123.1 3.49 Tahata et al. 2013 Doushantuo Fm (Member III) 587.78China Drill core n/a 123.29 4.28 Tahata et al. 2013 Doushantuo Fm (Member III) 587.92China Drill core n/a 123.45 4.29 Tahata et al. 2013 Doushantuo Fm (Member III) 588.04China Drill core n/a 123.64 4.21 Tahata et al. 2013 Doushantuo Fm (Member III) 588.18China Drill core n/a 123.97 4.11 Tahata et al. 2013 Doushantuo Fm (Member III) 588.42China Drill core n/a 124.09 4.23 Tahata et al. 2013 Doushantuo Fm (Member III) 588.51China Drill core n/a 124.22 4.16 Tahata et al. 2013 Doushantuo Fm (Member III) 588.61China Drill core n/a 124.37 4.42 Tahata et al. 2013 Doushantuo Fm (Member III) 588.72China Drill core n/a 124.47 4.52 Tahata et al. 2013 Doushantuo Fm (Member III) 588.80China Drill core n/a 125.03 4.89 Tahata et al. 2013 Doushantuo Fm (Member III) 589.22China Drill core n/a 125.22 4.33 Tahata et al. 2013 Doushantuo Fm (Member III) 589.36China Drill core n/a 125.3 4.3 Tahata et al. 2013 Doushantuo Fm (Member III) 589.42China Drill core n/a 125.45 4.71 Tahata et al. 2013 Doushantuo Fm (Member III) 589.53China Drill core n/a 125.6 3.99 Tahata et al. 2013 Doushantuo Fm (Member III) 589.64China Drill core n/a 125.78 4.48 Tahata et al. 2013 Doushantuo Fm (Member III) 589.77China Drill core n/a 126.7 5.55 Tahata et al. 2013 Doushantuo Fm (Member III) 590.46China Drill core n/a 126.87 5.5 Tahata et al. 2013 Doushantuo Fm (Member III) 590.59China Drill core n/a 127.03 5.48 Tahata et al. 2013 Doushantuo Fm (Member III) 590.71China Drill core n/a 127.15 5.62 Tahata et al. 2013 Doushantuo Fm (Member III) 590.80China Drill core n/a 127.29 5.82 Tahata et al. 2013 Doushantuo Fm (Member III) 590.90China Drill core n/a 127.33 5.75 Tahata et al. 2013 Doushantuo Fm (Member III) 590.93China Drill core n/a 127.49 5.8 Tahata et al. 2013 Doushantuo Fm (Member III) 591.05China Drill core n/a 127.65 5.78 Tahata et al. 2013 Doushantuo Fm (Member III) 591.17China Drill core n/a 127.76 5.83 Tahata et al. 2013 Doushantuo Fm (Member III) 591.25China Drill core n/a 128.63 5.03 Tahata et al. 2013 Doushantuo Fm (Member III) 591.90China Drill core n/a 128.88 5.22 Tahata et al. 2013 Doushantuo Fm (Member III) 592.09China Drill core n/a 130.26 4.65 Tahata et al. 2013 Doushantuo Fm (Member III) 593.12China Drill core n/a 131.4 3.93 Tahata et al. 2013 Doushantuo Fm (Member III) 593.97China Drill core n/a 131.66 3.86 Tahata et al. 2013 Doushantuo Fm (Member III) 594.16China Drill core n/a 131.82 3.6 Tahata et al. 2013 Doushantuo Fm (Member III) 594.28China Drill core n/a 131.98 3.75 Tahata et al. 2013 Doushantuo Fm (Member III) 594.40China Drill core n/a 132.16 3.6 Tahata et al. 2013 Doushantuo Fm (Member III) 594.53China Drill core n/a 132.75 3.11 Tahata et al. 2013 Doushantuo Fm (Member III) 594.97China Drill core n/a 132.88 3.44 Tahata et al. 2013 Doushantuo Fm (Member III) 595.07

China Drill core n/a 133.12 2.61 Tahata et al. 2013 Doushantuo Fm (Member III) 595.25China Drill core n/a 133.14 2.55 Tahata et al. 2013 Doushantuo Fm (Member III) 595.26China Drill core n/a 133.35 2.85 Tahata et al. 2013 Doushantuo Fm (Member III) 595.42China Drill core n/a 134.76 -1.32 Tahata et al. 2013 Doushantuo Fm (Member III) 596.47China Drill core n/a 134.97 -0.84 Tahata et al. 2013 Doushantuo Fm (Member III) 596.63China Drill core n/a 135.25 -1.22 Tahata et al. 2013 Doushantuo Fm (Member III) 596.84China Drill core n/a 135.52 -1.02 Tahata et al. 2013 Doushantuo Fm (Member III) 597.04China Drill core n/a 135.65 -1.03 Tahata et al. 2013 Doushantuo Fm (Member III) 597.14China Drill core n/a 135.9 0.06 Tahata et al. 2013 Doushantuo Fm (Member III) 597.32China Drill core n/a 138.19 -3.92 Tahata et al. 2013 Doushantuo Fm (Member III) 599.03China Drill core n/a 139.26 -5.13 Tahata et al. 2013 Doushantuo Fm (Member III) 599.83China Drill core n/a 140.31 -0.81 Tahata et al. 2013 Doushantuo Fm (Member III) 600.61China Drill core n/a 140.38 -0.46 Tahata et al. 2013 Doushantuo Fm (Member III) 600.66China Drill core n/a 140.46 -2 Tahata et al. 2013 Doushantuo Fm (Member III) 600.72China Drill core n/a 140.54 -2.51 Tahata et al. 2013 Doushantuo Fm (Member III) 600.78China Drill core n/a 140.91 -2.24 Tahata et al. 2013 Doushantuo Fm (Member III) 601.06China Drill core n/a 141.13 -1.19 Tahata et al. 2013 Doushantuo Fm (Member III) 601.22China Drill core n/a 141.26 -0.89 Tahata et al. 2013 Doushantuo Fm (Member III) 601.32China Drill core n/a 141.45 -1.35 Tahata et al. 2013 Doushantuo Fm (Member III) 601.46China Drill core n/a 141.68 -4.22 Tahata et al. 2013 Doushantuo Fm (Member III) 601.63China Drill core n/a 141.81 -4.12 Tahata et al. 2013 Doushantuo Fm (Member III) 601.73China Drill core n/a 141.92 -1.78 Tahata et al. 2013 Doushantuo Fm (Member III) 601.81China Drill core n/a 142.05 -1.37 Tahata et al. 2013 Doushantuo Fm (Member III) 601.91China Drill core n/a 142.31 -0.54 Tahata et al. 2013 Doushantuo Fm (Member III) 602.10China Drill core n/a 142.46 -1.62 Tahata et al. 2013 Doushantuo Fm (Member III) 602.22China Drill core n/a 142.52 -2.74 Tahata et al. 2013 Doushantuo Fm (Member III) 602.26China Drill core n/a 142.69 -2.77 Tahata et al. 2013 Doushantuo Fm (Member III) 602.39China Drill core n/a 143.33 -1.96 Tahata et al. 2013 Doushantuo Fm (Member III) 602.86China Drill core n/a 144.41 -2.36 Tahata et al. 2013 Doushantuo Fm (Member III) 603.67China Drill core n/a 145.29 -1.72 Tahata et al. 2013 Doushantuo Fm (Member III) 604.33China Drill core n/a 145.72 -0.67 Tahata et al. 2013 Doushantuo Fm (Member III) 604.65China Drill core n/a 146.04 -3.17 Tahata et al. 2013 Doushantuo Fm (Member III) 604.89China Drill core n/a 146.84 -4.19 Tahata et al. 2013 Doushantuo Fm (Member III) 605.48China Drill core n/a 147.11 -3.9 Tahata et al. 2013 Doushantuo Fm (Member III) 605.68China Drill core n/a 147.96 -2.39 Tahata et al. 2013 Doushantuo Fm (Member III) 606.32China Drill core n/a 148.05 -2.47 Tahata et al. 2013 Doushantuo Fm (Member III) 606.38China Drill core n/a 148.42 -3.17 Tahata et al. 2013 Doushantuo Fm (Member III) 606.66China Drill core n/a 148.64 -3.44 Tahata et al. 2013 Doushantuo Fm (Member III) 606.82China Drill core n/a 148.72 -3.4 Tahata et al. 2013 Doushantuo Fm (Member III) 606.88China Drill core n/a 149.75 -2.75 Tahata et al. 2013 Doushantuo Fm (Member III) 607.65China Drill core n/a 149.9 -2.41 Tahata et al. 2013 Doushantuo Fm (Member III) 607.76China Drill core n/a 150.34 -4.33 Tahata et al. 2013 Doushantuo Fm (Member III) 608.09China Drill core n/a 150.52 -3.61 Tahata et al. 2013 Doushantuo Fm (Member III) 608.23China Drill core n/a 150.77 -3.24 Tahata et al. 2013 Doushantuo Fm (Member III) 608.41China Drill core n/a 150.96 -3.6 Tahata et al. 2013 Doushantuo Fm (Member III) 608.56China Drill core n/a 151.12 -3.31 Tahata et al. 2013 Doushantuo Fm (Member III) 608.67China Drill core n/a 151.3 -3.49 Tahata et al. 2013 Doushantuo Fm (Member III) 608.81China Drill core n/a 151.76 -2.84 Tahata et al. 2013 Doushantuo Fm (Member III) 609.15China Drill core n/a 151.98 -3.57 Tahata et al. 2013 Doushantuo Fm (Member III) 609.32China Drill core n/a 152.13 -3.62 Tahata et al. 2013 Doushantuo Fm (Member III) 609.43China Drill core n/a 152.37 -3.93 Tahata et al. 2013 Doushantuo Fm (Member III) 609.61

China Drill core n/a 158.26 1.3 Tahata et al. 2013 Doushantuo Fm (Member II) 614.00

Ash at the top of Doushantuo member II dated by SHRIMP on zircon by Liu et al. 2009. As recalculated in GTS 2012.

China Drill core n/a 158.42 0.72 Tahata et al. 2013 Doushantuo Fm (Member II) 614.03China Drill core n/a 159.08 1.75 Tahata et al. 2013 Doushantuo Fm (Member II) 614.13China Drill core n/a 161.3 2.24 Tahata et al. 2013 Doushantuo Fm (Member II) 614.48China Drill core n/a 161.77 1.3 Tahata et al. 2013 Doushantuo Fm (Member II) 614.55China Drill core n/a 163.59 4.09 Tahata et al. 2013 Doushantuo Fm (Member II) 614.84China Drill core n/a 165.54 3.77 Tahata et al. 2013 Doushantuo Fm (Member II) 615.14China Drill core n/a 165.76 4.68 Tahata et al. 2013 Doushantuo Fm (Member II) 615.18China Drill core n/a 169.12 5.09 Tahata et al. 2013 Doushantuo Fm (Member II) 615.70China Drill core n/a 169.25 4.98 Tahata et al. 2013 Doushantuo Fm (Member II) 615.72China Drill core n/a 169.47 5.18 Tahata et al. 2013 Doushantuo Fm (Member II) 615.76China Drill core n/a 174.08 5.15 Tahata et al. 2013 Doushantuo Fm (Member II) 616.48China Drill core n/a 174.84 5.86 Tahata et al. 2013 Doushantuo Fm (Member II) 616.60China Drill core n/a 175.06 6.05 Tahata et al. 2013 Doushantuo Fm (Member II) 616.64China Drill core n/a 175.3 5.91 Tahata et al. 2013 Doushantuo Fm (Member II) 616.67China Drill core n/a 175.68 6.04 Tahata et al. 2013 Doushantuo Fm (Member II) 616.73China Drill core n/a 176.43 6.09 Tahata et al. 2013 Doushantuo Fm (Member II) 616.85China Drill core n/a 176.54 6.1 Tahata et al. 2013 Doushantuo Fm (Member II) 616.87China Drill core n/a 180.54 5.51 Tahata et al. 2013 Doushantuo Fm (Member II) 617.50China Drill core n/a 180.69 5.61 Tahata et al. 2013 Doushantuo Fm (Member II) 617.52China Drill core n/a 180.81 5.52 Tahata et al. 2013 Doushantuo Fm (Member II) 617.54China Drill core n/a 184.36 2.83 Tahata et al. 2013 Doushantuo Fm (Member II) 618.10China Drill core n/a 186.14 4.3 Tahata et al. 2013 Doushantuo Fm (Member II) 618.37China Drill core n/a 186.56 3.93 Tahata et al. 2013 Doushantuo Fm (Member II) 618.44China Drill core n/a 189.39 3.85 Tahata et al. 2013 Doushantuo Fm (Member II) 618.88China Drill core n/a 191.38 4.62 Tahata et al. 2013 Doushantuo Fm (Member II) 619.20China Drill core n/a 191.61 4.52 Tahata et al. 2013 Doushantuo Fm (Member II) 619.23China Drill core n/a 191.72 4.38 Tahata et al. 2013 Doushantuo Fm (Member II) 619.25China Drill core n/a 194.28 3.74 Tahata et al. 2013 Doushantuo Fm (Member II) 619.65China Drill core n/a 196.37 2.58 Tahata et al. 2013 Doushantuo Fm (Member II) 619.98China Drill core n/a 201.82 3.29 Tahata et al. 2013 Doushantuo Fm (Member II) 620.84China Drill core n/a 201.94 3.32 Tahata et al. 2013 Doushantuo Fm (Member II) 620.85China Drill core n/a 205.2 4.74 Tahata et al. 2013 Doushantuo Fm (Member II) 621.37China Drill core n/a 208.25 4.86 Tahata et al. 2013 Doushantuo Fm (Member II) 621.84China Drill core n/a 208.39 4.52 Tahata et al. 2013 Doushantuo Fm (Member II) 621.87China Drill core n/a 209.05 4.54 Tahata et al. 2013 Doushantuo Fm (Member II) 621.97China Drill core n/a 209.27 4.44 Tahata et al. 2013 Doushantuo Fm (Member II) 622.00China Drill core n/a 211.95 5.83 Tahata et al. 2013 Doushantuo Fm (Member II) 622.42China Drill core n/a 212.03 5.29 Tahata et al. 2013 Doushantuo Fm (Member II) 622.44China Drill core n/a 214.43 5.1 Tahata et al. 2013 Doushantuo Fm (Member II) 622.81China Drill core n/a 215.28 5.29 Tahata et al. 2013 Doushantuo Fm (Member II) 622.95China Drill core n/a 215.39 5.28 Tahata et al. 2013 Doushantuo Fm (Member II) 622.96China Drill core n/a 215.6 5.12 Tahata et al. 2013 Doushantuo Fm (Member II) 623.00China Drill core n/a 218.51 4.07 Tahata et al. 2013 Doushantuo Fm (Member II) 623.45China Drill core n/a 218.63 3.63 Tahata et al. 2013 Doushantuo Fm (Member II) 623.47China Drill core n/a 219.71 3.19 Tahata et al. 2013 Doushantuo Fm (Member II) 623.64China Drill core n/a 219.81 3.07 Tahata et al. 2013 Doushantuo Fm (Member II) 623.66China Drill core n/a 219.93 3.11 Tahata et al. 2013 Doushantuo Fm (Member II) 623.68China Drill core n/a 221.13 4.81 Tahata et al. 2013 Doushantuo Fm (Member II) 623.87China Drill core n/a 221.39 5.06 Tahata et al. 2013 Doushantuo Fm (Member II) 623.91China Drill core n/a 222.24 4.71 Tahata et al. 2013 Doushantuo Fm (Member II) 624.04China Drill core n/a 223.82 2.46 Tahata et al. 2013 Doushantuo Fm (Member II) 624.29China Drill core n/a 223.97 3.1 Tahata et al. 2013 Doushantuo Fm (Member II) 624.31China Drill core n/a 225.16 2.91 Tahata et al. 2013 Doushantuo Fm (Member II) 624.50China Drill core n/a 225.57 0.86 Tahata et al. 2013 Doushantuo Fm (Member II) 624.56China Drill core n/a 225.76 0.92 Tahata et al. 2013 Doushantuo Fm (Member II) 624.59China Drill core n/a 225.93 -0.93 Tahata et al. 2013 Doushantuo Fm (Member II) 624.62China Drill core n/a 226.65 -3.63 Tahata et al. 2013 Doushantuo Fm (Member II) 624.73China Drill core n/a 228.14 2.46 Tahata et al. 2013 Doushantuo Fm (Member II) 624.97China Drill core n/a 229.68 3.31 Tahata et al. 2013 Doushantuo Fm (Member II) 625.21China Drill core n/a 230.16 3.96 Tahata et al. 2013 Doushantuo Fm (Member II) 625.28China Drill core n/a 230.25 4.1 Tahata et al. 2013 Doushantuo Fm (Member II) 625.30China Drill core n/a 230.5 4.97 Tahata et al. 2013 Doushantuo Fm (Member II) 625.34China Drill core n/a 234.44 2.9 Tahata et al. 2013 Doushantuo Fm (Member II) 625.95China Drill core n/a 237.2 4.47 Tahata et al. 2013 Doushantuo Fm (Member II) 626.39China Drill core n/a 237.32 4.43 Tahata et al. 2013 Doushantuo Fm (Member II) 626.41China Drill core n/a 240.87 4.59 Tahata et al. 2013 Doushantuo Fm (Member II) 626.96China Drill core n/a 240.97 4.65 Tahata et al. 2013 Doushantuo Fm (Member II) 626.98China Drill core n/a 245.99 5.87 Tahata et al. 2013 Doushantuo Fm (Member II) 627.77China Drill core n/a 246.19 5.63 Tahata et al. 2013 Doushantuo Fm (Member II) 627.80China Drill core n/a 246.3 5.48 Tahata et al. 2013 Doushantuo Fm (Member II) 627.81China Drill core n/a 246.4 6.3 Tahata et al. 2013 Doushantuo Fm (Member II) 627.83China Drill core n/a 248.25 5.33 Tahata et al. 2013 Doushantuo Fm (Member II) 628.12China Drill core n/a 248.35 5.56 Tahata et al. 2013 Doushantuo Fm (Member II) 628.14China Drill core n/a 250.6 5.99 Tahata et al. 2013 Doushantuo Fm (Member II) 628.49China Drill core n/a 250.82 6.11 Tahata et al. 2013 Doushantuo Fm (Member II) 628.52China Drill core n/a 254.77 5.96 Tahata et al. 2013 Doushantuo Fm (Member II) 629.14China Drill core n/a 255.08 5.48 Tahata et al. 2013 Doushantuo Fm (Member II) 629.19China Drill core n/a 255.24 5.12 Tahata et al. 2013 Doushantuo Fm (Member II) 629.22China Drill core n/a 256.67 5.42 Tahata et al. 2013 Doushantuo Fm (Member II) 629.44China Drill core n/a 259.99 5.8 Tahata et al. 2013 Doushantuo Fm (Member II) 629.96China Drill core n/a 260.07 5.44 Tahata et al. 2013 Doushantuo Fm (Member II) 629.98China Drill core n/a 262.47 1.83 Tahata et al. 2013 Doushantuo Fm (Member II) 630.35China Drill core n/a 262.71 2.05 Tahata et al. 2013 Doushantuo Fm (Member II) 630.39China Drill core n/a 262.88 5.07 Tahata et al. 2013 Doushantuo Fm (Member II) 630.42China Drill core n/a 264.13 0.28 Tahata et al. 2013 Doushantuo Fm (Member II) 630.61China Drill core n/a 267.06 0.47 Tahata et al. 2013 Doushantuo Fm (Member II) 631.07China Drill core n/a 267.08 0.36 Tahata et al. 2013 Doushantuo Fm (Member II) 631.08China Drill core n/a 267.39 1 Tahata et al. 2013 Doushantuo Fm (Member II) 631.12China Drill core n/a 267.44 1.19 Tahata et al. 2013 Doushantuo Fm (Member II) 631.13China Drill core n/a 267.56 1.39 Tahata et al. 2013 Doushantuo Fm (Member II) 631.15China Drill core n/a 267.58 1.45 Tahata et al. 2013 Doushantuo Fm (Member II) 631.15China Drill core n/a 267.7 3.67 Tahata et al. 2013 Doushantuo Fm (Member II) 631.17China Drill core n/a 268.72 -2.62 Tahata et al. 2013 Doushantuo Fm (Member II) 631.33China Drill core n/a 269.41 3.69 Tahata et al. 2013 Doushantuo Fm (Member II) 631.44China Drill core n/a 269.57 -0.99 Tahata et al. 2013 Doushantuo Fm (Member II) 631.47China Drill core n/a 269.67 -0.51 Tahata et al. 2013 Doushantuo Fm (Member II) 631.48China Drill core n/a 269.96 -0.98 Tahata et al. 2013 Doushantuo Fm (Member II) 631.53China Drill core n/a 270.11 -1.47 Tahata et al. 2013 Doushantuo Fm (Member II) 631.55China Drill core n/a 270.16 -2.34 Tahata et al. 2013 Doushantuo Fm (Member II) 631.56China Drill core n/a 270.34 -3.98 Tahata et al. 2013 Doushantuo Fm (Member II) 631.59China Drill core n/a 272.23 -4.48 Tahata et al. 2013 Doushantuo Fm (Member II) 631.88China Drill core n/a 273.54 -1.33 Tahata et al. 2013 Doushantuo Fm (Member II) 632.09China Drill core n/a 275.86 -2.53 Tahata et al. 2013 Doushantuo Fm (Member II) 632.45China Drill core n/a 276.03 3.34 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 632.48China Drill core n/a 276.73 3.03 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 632.81China Drill core n/a 277.12 3.95 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.00China Drill core n/a 277.25 3.41 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.06China Drill core n/a 277.4 2.55 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.13China Drill core n/a 277.5 3.94 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.18China Drill core n/a 277.83 0.8 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.34China Drill core n/a 277.97 2.35 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.40China Drill core n/a 278.06 -0.78 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.45China Drill core n/a 278.23 -1.3 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.53China Drill core n/a 278.91 -9.57 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.85China Drill core n/a 279 -5.56 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 633.89China Drill core n/a 279.28 -3.5 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.03China Drill core n/a 279.5 -3.21 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.13China Drill core n/a 279.6 -2.82 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.18China Drill core n/a 279.65 -1.88 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.20China Drill core n/a 279.74 -3.71 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.25China Drill core n/a 279.81 -3.04 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.28China Drill core n/a 279.89 -3.03 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.32China Drill core n/a 280 -2.54 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.37China Drill core n/a 280.07 -2.56 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.40China Drill core n/a 280.15 -2.14 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.44China Drill core n/a 280.19 -1.32 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.46China Drill core n/a 280.29 -2.46 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.51China Drill core n/a 280.36 -2.57 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.54China Drill core n/a 280.36 -2.9 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.54

China Drill core n/a 280.42 -2.48 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.57China Drill core n/a 280.48 -2.92 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.60China Drill core n/a 280.52 -2.3 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.62China Drill core n/a 280.57 -2.58 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.64China Drill core n/a 280.66 -2.26 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.68China Drill core n/a 280.69 -1.55 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 634.70China Drill core n/a 281.74 -2.96 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 635.20

China Drill core n/a 281.87 -3.5 Tahata et al. 2013 Doushantuo Fm (Member I, cap carbonate) 635.26

ID-TIMS U-Pb date on ash layer in Doushantuo Fm, China. ~10 meters above Nantuo diamictite (Marinoan glacial). Condon et al. 2005. As recalculated in GTS 2012.

China Jinunongwan 155.50 n/a -5.02 Jiang et al. 2007 Doushantuo (Member IV) 551.09Condon et al. 2005 U-Pb TIMS zircon age; identified at this layer by Jiang et al., 2007.

China Jinunongwan 156.00 n/a -1.8 Jiang et al. 2007 Doushantuo (Member IV) 551.06China Jinunongwan 156.20 n/a -1.75 Jiang et al. 2007 Dengying Fm 551.05China Jinunongwan 156.40 n/a -1.23 Jiang et al. 2007 Dengying Fm 551.03China Jinunongwan 159.00 n/a 0.92 Jiang et al. 2007 Dengying Fm 550.88China Jinunongwan 163.00 n/a 1.7 Jiang et al. 2007 Dengying Fm 550.63China Jinunongwan 166.00 n/a 5.86 Jiang et al. 2007 Dengying Fm 550.45China Jinunongwan 170.00 n/a 5.86 Jiang et al. 2007 Dengying Fm 550.20China Jinunongwan 172.00 n/a 6.65 Jiang et al. 2007 Dengying Fm 550.08China Jinunongwan 176.00 n/a 4.8 Jiang et al. 2007 Dengying Fm 549.83China Jinunongwan 179.00 n/a 4.36 Jiang et al. 2007 Dengying Fm 549.65China Jinunongwan 182.00 n/a 4.02 Jiang et al. 2007 Dengying Fm 549.47China Jinunongwan 185.00 n/a 3.79 Jiang et al. 2007 Dengying Fm 549.28China Jinunongwan 189.00 n/a 4.12 Jiang et al. 2007 Dengying Fm 549.04China Jinunongwan 192.00 n/a 4.01 Jiang et al. 2007 Dengying Fm 548.85China Jinunongwan 195.00 n/a 3.38 Jiang et al. 2007 Dengying Fm 548.67China Jinunongwan 199.00 n/a 4.17 Jiang et al. 2007 Dengying Fm 548.42China Jinunongwan 203.00 n/a 4.3 Jiang et al. 2007 Dengying Fm 548.18China Jinunongwan 205.00 n/a 4.11 Jiang et al. 2007 Dengying Fm 548.06China Jinunongwan 208.00 n/a 3.69 Jiang et al. 2007 Dengying Fm 547.87China Jinunongwan 211.00 n/a 3.15 Jiang et al. 2007 Dengying Fm 547.69China Jinunongwan 215.00 n/a 2.7 Jiang et al. 2007 Dengying Fm 547.44China Shipai section 217.00 n/a 3.95 Jiang et al. 2007 Dengying Fm 547.32China Shipai section 218.60 n/a 1.617 Jiang et al. 2007 Dengying Fm 547.29China Shipai section 229.80 n/a 2.632 Jiang et al. 2007 Dengying Fm 547.10China Shipai section 241.10 n/a 2.299 Jiang et al. 2007 Dengying Fm 546.90China Shipai section 253.80 n/a 0.879 Jiang et al. 2007 Dengying Fm 546.67China Shipai section 265.20 n/a 1.622 Jiang et al. 2007 Dengying Fm 546.47China Shipai section 281.20 n/a 2.668 Jiang et al. 2007 Dengying Fm 546.19China Shipai section 281.30 n/a 2.784 Jiang et al. 2007 Dengying Fm 546.19China Shipai section 288.40 n/a 2.007 Jiang et al. 2007 Dengying Fm 546.07China Shipai section 307.90 n/a 1.649 Jiang et al. 2007 Dengying Fm 545.72China Shipai section 331.20 n/a 1.329 Jiang et al. 2007 Dengying Fm 545.31China Shipai section 338.10 n/a 3.326 Jiang et al. 2007 Dengying Fm 545.19China Shipai section 345.00 n/a 4.118 Jiang et al. 2007 Dengying Fm 545.07China Shipai section 350.80 n/a 5.258 Jiang et al. 2007 Dengying Fm 544.97China Shipai section 356.20 n/a 3.244 Jiang et al. 2007 Dengying Fm 544.88China Shipai section 362.90 n/a 4.201 Jiang et al. 2007 Dengying Fm 544.76China Shipai section 367.30 n/a 3.386 Jiang et al. 2007 Dengying Fm 544.68China Shipai section 372.90 n/a 4.016 Jiang et al. 2007 Dengying Fm 544.58China Shipai section 378.20 n/a 3.279 Jiang et al. 2007 Dengying Fm 544.49China Shipai section 383.80 n/a 3.184 Jiang et al. 2007 Dengying Fm 544.39China Shipai section 390.80 n/a 3.117 Jiang et al. 2007 Dengying Fm 544.27China Shipai section 398.10 n/a 3.036 Jiang et al. 2007 Dengying Fm 544.14China Shipai section 403.00 n/a 3.017 Jiang et al. 2007 Dengying Fm 544.05China Shipai section 408.20 n/a 3.313 Jiang et al. 2007 Dengying Fm 543.96China Shipai section 414.20 n/a 2.025 Jiang et al. 2007 Dengying Fm 543.86China Shipai section 419.90 n/a 4.76 Jiang et al. 2007 Dengying Fm 543.76China Shipai section 429.40 n/a 3.07 Jiang et al. 2007 Dengying Fm 543.59China Shipai section 436.80 n/a 3.013 Jiang et al. 2007 Dengying Fm 543.46China Shipai section 447.50 n/a 3.493 Jiang et al. 2007 Dengying Fm 543.27China Shipai section 456.70 n/a 2.42 Jiang et al. 2007 Dengying Fm 543.11China Shipai section 464.00 n/a 1.621 Jiang et al. 2007 Dengying Fm 542.98China Shipai section 470.00 n/a 2.08 Jiang et al. 2007 Dengying Fm 542.88China Shipai section 476.00 n/a 1.413 Jiang et al. 2007 Dengying Fm 542.77China Shipai section 482.20 n/a 2.896 Jiang et al. 2007 Dengying Fm 542.66China Shipai section 490.00 n/a 3.135 Jiang et al. 2007 Dengying Fm 542.53China Shipai section 497.60 n/a 2.994 Jiang et al. 2007 Dengying Fm 542.39China Shipai section 506.50 n/a 2.472 Jiang et al. 2007 Dengying Fm 542.24China Shipai section 515.60 n/a 2.063 Jiang et al. 2007 Dengying Fm 542.08China Shipai section 531.50 n/a 2.262 Jiang et al. 2007 Dengying Fm 541.80China Shipai section 545.20 n/a 2.733 Jiang et al. 2007 Dengying Fm 541.56China Shipai section 551.90 n/a 2.764 Jiang et al. 2007 Dengying Fm 541.44China Shipai section 558.20 n/a 1.552 Jiang et al. 2007 Dengying Fm 541.33China Shipai section 565.20 n/a 2.961 Jiang et al. 2007 Dengying Fm 541.21China Shipai section 572.20 n/a 2.528 Jiang et al. 2007 Dengying Fm 541.08China Shipai section 578.10 n/a 2.52 Jiang et al. 2007 Dengying Fm 540.98China Shipai section 584.30 n/a 1.85 Jiang et al. 2007 Dengying Fm 540.87China Shipai section 590.00 n/a 2.84 Jiang et al. 2007 Dengying Fm 540.77China Shipai section 594.00 n/a 3.113 Jiang et al. 2007 Dengying Fm 540.70China Shipai section 598.80 n/a 2.965 Jiang et al. 2007 Dengying Fm 540.62China Shipai section 603.80 n/a 2.791 Jiang et al. 2007 Dengying Fm 540.53China Shipai section 607.20 n/a 2.687 Jiang et al. 2007 Dengying Fm 540.47China Shipai section 612.30 n/a 2.586 Jiang et al. 2007 Dengying Fm 540.38China Shipai section 621.80 n/a 3.033 Jiang et al. 2007 Dengying Fm 540.21China Shipai section 643.50 n/a 2.541 Jiang et al. 2007 Dengying Fm 539.83China Shipai section 652.00 n/a 3.033 Jiang et al. 2007 Dengying Fm 539.68China Shipai section 661.00 n/a 2.873 Jiang et al. 2007 Dengying Fm 539.52China Shipai section 670.00 n/a 3.179 Jiang et al. 2007 Dengying Fm 539.37China Shipai section 678.00 n/a 2.472 Jiang et al. 2007 Dengying Fm 539.23China Shipai section 686.00 n/a 0.09 Jiang et al. 2007 Dengying Fm 539.08China Shipai section 694.20 n/a -0.144 Jiang et al. 2007 Dengying Fm 538.94

China Shipai section 707.90 n/a -0.576 Jiang et al. 2007 Dengying Fm 538.7

Precambrian-Cambrian boundary. Age after Linnemann et al. 2018, a combined paleontological study + ID-TIMS U-Pb ash dates on Swartpunt section, Namibia, suggest moving the Precambrian-Cambrian boundary younger, between 538.8 and 538.6 Ma.

Brazil Laginha Mine western base 0.00 n/a Boggiani et al. 2010 Tamengo Fm 555.18

Tuff dated by TIMS, upper Bocaina Fm, Parry et al. 2017. Minimum depositional age for Tamengo Fm. Ocurrs below a small negative excursion.

Brazil Laginha Mine western base 0.70 n/a -3.64 Boggiani et al. 2010 Tamengo Fm 554.99Brazil Laginha Mine western base 2.10 n/a -3.23 Boggiani et al. 2010 Tamengo Fm 554.57Brazil Laginha Mine western 3.20 n/a -0.11 Boggiani et al. 2010 Tamengo Fm 554.28Brazil Laginha Mine western base 4.80 n/a -0.71 Boggiani et al. 2010 Tamengo Fm 553.82Brazil Laginha Mine western base 7.00 n/a -0.56 Boggiani et al. 2010 Tamengo Fm 553.18Brazil Laginha Mine western 8.30 n/a -0.43 Boggiani et al. 2010 Tamengo Fm 552.82Brazil Laginha Mine western base 8.90 n/a -1.12 Boggiani et al. 2010 Tamengo Fm 552.66Brazil Laginha Mine western base 11.00 n/a -0.31 Boggiani et al. 2010 Tamengo Fm 552.05Brazil Laginha Mine western base 12.40 n/a -0.29 Boggiani et al. 2010 Tamengo Fm 551.66Brazil Laginha Mine western base 14.40 n/a -0.4 Boggiani et al. 2010 Tamengo Fm 551.07Brazil Laginha Mine western base 15.50 n/a -1.38 Boggiani et al. 2010 Tamengo Fm 550.76Brazil Laginha Mine western base 17.30 n/a -0.95 Boggiani et al. 2010 Tamengo Fm 550.26Brazil Laginha Mine western base 19.20 n/a -1.46 Boggiani et al. 2010 Tamengo Fm 549.71Brazil Laginha Mine western 20.00 n/a -3.32 Boggiani et al. 2010 Tamengo Fm 549.48Brazil Laginha Mine western base 20.40 n/a -1.13 Boggiani et al. 2010 Tamengo Fm 549.37Brazil Laginha Mine western base 22.00 n/a -1.07 Boggiani et al. 2010 Tamengo Fm 548.91Brazil Laginha Mine western 22.60 n/a 0.27 Boggiani et al. 2010 Tamengo Fm 548.76Brazil Laginha Mine western base 23.30 n/a -1.1 Boggiani et al. 2010 Tamengo Fm 548.56Brazil Laginha Mine western 23.60 n/a 0.42 Boggiani et al. 2010 Tamengo Fm 548.46Brazil Laginha Mine western base 24.60 n/a -1.28 Boggiani et al. 2010 Tamengo Fm 548.17Brazil Laginha Mine western base 25.60 n/a -1.34 Boggiani et al. 2010 Tamengo Fm 547.88Brazil Laginha Mine western base 27.20 n/a -1.35 Boggiani et al. 2010 Tamengo Fm 547.45Brazil Laginha Mine western 27.30 n/a 4.59 Boggiani et al. 2010 Tamengo Fm 547.42Brazil Laginha Mine western base 28.50 n/a -1.51 Boggiani et al. 2010 Tamengo Fm 547.08Brazil Laginha Mine western base 30.20 n/a -1.89 Boggiani et al. 2010 Tamengo Fm 546.57Brazil Laginha Mine western base 31.50 n/a -1.1 Boggiani et al. 2010 Tamengo Fm 546.23Brazil Laginha Mine western 32.00 n/a 1.3 Boggiani et al. 2010 Tamengo Fm 546.08Brazil Laginha Mine western base 33.00 n/a -0.36 Boggiani et al. 2010 Tamengo Fm 545.79Brazil Laginha Mine western base 36.20 n/a 0.45 Boggiani et al. 2010 Tamengo Fm 544.88Brazil Laginha Mine western base 37.00 n/a 0.13 Boggiani et al. 2010 Tamengo Fm 544.64Brazil Laginha Mine western base 38.30 n/a 0.97 Boggiani et al. 2010 Tamengo Fm 544.29Brazil Laginha Mine western base 39.40 n/a -0.56 Boggiani et al. 2010 Tamengo Fm 543.98Brazil Laginha Mine western base 40.40 n/a 0.34 Boggiani et al. 2010 Tamengo Fm 543.68Brazil Laginha Mine western base 42.60 n/a 0.56 Boggiani et al. 2010 Tamengo Fm 543.07Brazil Laginha Mine western base 44.00 n/a 0.54 Boggiani et al. 2010 Tamengo Fm 542.65

Brazil Laginha Mine western 45.00 n/a 1.87 Boggiani et al. 2010 Tamengo Fm 542.37

Tuff dated by TIMS, Tamengo Fm (upper). Occurs within +2 δ13C permille plateau. Parry et al. 2017.

Brazil Laginha Mine western base 45.40 n/a 3.18 Boggiani et al. 2010 Tamengo Fm 542.36Brazil Laginha Mine western 50.40 n/a 2.6 Boggiani et al. 2010 Tamengo Fm 542.25Brazil Laginha Mine western 52.80 n/a 3.15 Boggiani et al. 2010 Tamengo Fm 542.20Brazil Laginha Mine western 57.20 n/a 3.11 Boggiani et al. 2010 Tamengo Fm 542.10Brazil Laginha Mine western 59.70 n/a 1.39 Boggiani et al. 2010 Tamengo Fm 542.04

Brazil Laginha Mine western 68.40 n/a 2.75 Boggiani et al. 2010 Tamengo Fm 541.85Tuff dated by TIMS, basal Guicaras Fm, Parry et al. 2017.

Namibia Southern sub-basin 0.00 n/a Saylor et al. 1998, digitized from figure 2D Kaines Member 550

Estimated onset of deposition of Kaines Member in Witputs subbasin, Namibia. Estimate made on the basis of chemostratigraphic correlation of units upsection.

Namibia Southern sub-basin 55.00 n/a -1.4 Saylor et al. 1998, digitized from figure 2D Kaines Member 549.43Namibia Southern sub-basin 57.00 n/a -3.6 Saylor et al. 1998, digitized from figure 2D Kaines Member 549.40Namibia Southern sub-basin 68.00 n/a -3.6 Saylor et al. 1998, digitized from figure 2D Mara Member 549.29Namibia Southern sub-basin 68.00 n/a -2.1 Saylor et al. 1998, digitized from figure 2D Mara Member 549.29Namibia Southern sub-basin 77.00 n/a -2.7 Saylor et al. 1998, digitized from figure 2D Mara Member 549.20Namibia Southern sub-basin 92.00 n/a -2.7 Saylor et al. 1998, digitized from figure 2D Mara Member 549.03Namibia Southern sub-basin 98.00 n/a -1.6 Saylor et al. 1998, digitized from figure 2D Mara Member 548.97Namibia Southern sub-basin 133.00 n/a -3.7 Saylor et al. 1998, digitized from figure 2D Kliphoek Member 548.60Namibia Southern sub-basin 162.00 n/a 2.4 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.30Namibia Southern sub-basin 164.00 n/a -0.3 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.28Namibia Southern sub-basin 171.00 n/a 0.3 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.21Namibia Southern sub-basin 171.00 n/a 0.6 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.21Namibia Southern sub-basin 173.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.18Namibia Southern sub-basin 173.00 n/a 2.7 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.18Namibia Southern sub-basin 188.00 n/a 2.2 Saylor et al. 1998, digitized from figure 2D Mooifontein Member 548.02Namibia Southern sub-basin 425.00 n/a 1.5 Saylor et al. 1998, digitized from figure 2D Nasep Member 545.54Namibia Southern sub-basin 440.00 n/a 2.1 Saylor et al. 1998, digitized from figure 2D Nasep Member 545.38Namibia Southern sub-basin 573.00 n/a 2 Saylor et al. 1998, digitized from figure 2D Huns Member 543.98Namibia Southern sub-basin 602.00 n/a 1.4 Saylor et al. 1998, digitized from figure 2D Huns Member 543.68Namibia Southern sub-basin 635.00 n/a 2.2 Saylor et al. 1998, digitized from figure 2D Huns Member 543.34Namibia Southern sub-basin 670.00 n/a 2.3 Saylor et al. 1998, digitized from figure 2D Huns Member 542.97Namibia Southern sub-basin 705.00 n/a 1.9 Saylor et al. 1998, digitized from figure 2D Huns Member 542.60Namibia Southern sub-basin 746.00 n/a 2.3 Saylor et al. 1998, digitized from figure 2D Huns Member 542.16Namibia Southern sub-basin 783.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Huns Member 541.77Namibia Southern sub-basin 838.00 n/a 2.1 Saylor et al. 1998, digitized from figure 2D Huns Member 541.20

Namibia Southern sub-basin 943.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 540.095Spitskop member ash, southern subbasin, within +2 δ13C permille plateau. Linnemann et al. 2018

Namibia Southern sub-basin 958.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 540.04Namibia Southern sub-basin 972.00 n/a 2.5 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 540.00Namibia Southern sub-basin 989.00 n/a 2.1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.94Namibia Southern sub-basin 1009.00 n/a 2.1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.88Namibia Southern sub-basin 1022.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.84Namibia Southern sub-basin 1033.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.80Namibia Southern sub-basin 1055.00 n/a 1.5 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.73Namibia Southern sub-basin 1063.00 n/a 2.1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.70Namibia Southern sub-basin 1077.00 n/a 1.1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.66Namibia Southern sub-basin 1088.00 n/a 1.5 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.62Namibia Southern sub-basin 1114.00 n/a 1.8 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.54Namibia Southern sub-basin 1186.00 n/a 1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.30Namibia Southern sub-basin 1197.00 n/a 2 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.27Namibia Southern sub-basin 1204.00 n/a 1.6 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.24Namibia Southern sub-basin 1276.00 n/a 1.2 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 539.01Namibia Southern sub-basin 1282.00 n/a -1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.99Namibia Southern sub-basin 1289.00 n/a 1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.97Namibia Southern sub-basin 1293.00 n/a 1.6 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.95Namibia Southern sub-basin 1304.00 n/a 1 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.92Namibia Southern sub-basin 1317.00 n/a 1.4 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.87Namibia Southern sub-basin 1324.00 n/a 0.9 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.85Namibia Southern sub-basin 1346.00 n/a 0.9 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.78Namibia Southern sub-basin 1352.00 n/a 1.6 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.76Namibia Southern sub-basin 1376.00 n/a 0 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.68Namibia Southern sub-basin 1376.00 n/a 1.2 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.68Namibia Southern sub-basin 1385.00 n/a 0.7 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.65Namibia Southern sub-basin 1396.00 n/a 1.9 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.62Namibia Southern sub-basin 1398.00 n/a 0.7 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.61Namibia Southern sub-basin 1407.00 n/a 1.2 Saylor et al. 1998, digitized from figure 2D Spitzkopf Member 538.58

Namibia n/a Nomtsas Fm 538.58

Nomstas Fm ash, Namibia. Southern subbasin, +2 δ13C permille plateau. Dated by U-Pb TIMS on zircon by Linnemann et al. 2018

Sample Isochron Re (ng/g) ± Os (pg/g) ± 192Os (pg/g) ± 187Re/188Os ± 187Os/188Os ± rhoa Osib

30 Well L 41.345 0.118 909.1 9.3 239.8 1.8 342.9918 2.7299 4.4592 0.0570 0.543 1.14031 159.444 0.393 3084.5 18.9 769.6 2.6 412.1811 1.7281 5.1469 0.0247 0.572 1.15932 192.669 0.473 3625.8 22.5 896.0 3.1 427.7917 1.8078 5.2690 0.0258 0.573 1.13028 163.530 0.400 2805.6 18.0 659.1 2.3 493.6122 2.0855 5.9341 0.0290 0.576 1.15834 288.910 0.706 4805.7 31.8 1109.4 3.9 518.0780 2.2189 6.1712 0.0315 0.567 1.15827 70.994 0.175 1128.5 7.6 253.7 0.9 556.7242 2.4284 6.5406 0.0333 0.584 1.16329 260.549 0.636 3823.0 25.4 815.4 2.8 635.7007 2.6535 7.3007 0.0350 0.575 1.15026 210.434 0.516 2880.3 20.6 583.7 2.1 717.1764 3.1518 8.0781 0.0424 0.579 1.139A A1707 1.397 0.005 160.7 0.8 59.2 0.3 46.9540 0.3075 1.0532 0.0080 0.590 0.608B 3.883 0.012 79.8 0.5 22.0 0.1 351.4028 1.9460 3.9508 0.0246 0.599 0.616C 4.976 0.017 61.5 0.5 12.3 0.1 802.7904 5.4531 8.2357 0.0618 0.676 0.616D 2.311 0.008 43.6 0.3 11.6 0.1 397.2155 2.9232 4.3846 0.0372 0.654 0.615E 0.821 0.005 205.1 0.8 77.7 0.3 21.0201 0.1603 0.8132 0.0050 0.404 0.6141 J1443 0.643 0.003 85.6 0.3 31.8 0.1 40.2820 0.2510 0.9895 0.0057 0.477 0.6022 7.487 0.019 348.3 1.3 117.7 1.2 126.4998 1.3294 1.8232 0.0187 0.967 0.6083 1.154 0.004 82.4 0.5 29.3 0.2 78.3031 0.5221 1.3591 0.0122 0.554 0.6074 0.790 0.003 56.3 0.3 20.0 0.1 78.5263 0.4857 1.3630 0.0087 0.544 0.6095 9.441 0.023 387.9 2.0 128.7 0.5 145.9664 0.6835 2.0024 0.0117 0.581 0.6003 Well M 86.7780 0.2128 3150.7 15.6 1014.9 3.6 170.1028 0.7336 2.2867 0.0116 0.576 0.6874 41.7632 0.1039 1378.0 6.9 435.6 1.5 190.7463 0.8186 2.4739 0.0123 0.575 0.6805 243.8726 0.5974 4703.2 27.9 1254.8 4.4 386.6377 1.6394 4.3239 0.0213 0.574 0.6876 25.6715 0.0637 781.9 4.3 242.3 0.9 210.7425 0.9610 2.6731 0.0147 0.584 0.6917 133.9473 0.3272 2250.8 14.0 560.5 2.0 475.4030 2.0213 5.1705 0.0255 0.578 0.6988 166.7851 0.4081 3403.1 20.0 931.4 3.3 356.2314 1.5233 4.0248 0.0202 0.572 0.6741 J1719 0.738 0.002 50.6 0.3 17.9 0.1 81.8245 0.5768 1.3908 0.0095 0.684 0.6052 1.104 0.004 61.4 0.3 21.3 0.1 103.2652 0.6476 1.5954 0.0116 0.622 0.6033 0.761 0.003 45.0 0.2 15.7 0.1 96.3474 0.7473 1.5345 0.0116 0.653 0.6094 0.821 0.008 79.3 0.4 28.9 0.1 56.5053 0.8440 1.1432 0.0081 0.559 0.6005 0.996 0.004 69.7 0.4 24.8 0.1 80.0356 0.5449 1.3700 0.0098 0.553 0.6016 3.547 0.013 131.7 0.8 42.9 0.2 164.6136 1.0067 2.1850 0.0152 0.576 0.6037 0.890 0.005 57.7 0.3 20.3 0.1 87.0138 0.9443 1.4346 0.0098 0.762 0.5998 13.769 0.050 312.1 2.0 89.0 0.4 307.6607 1.7531 3.5544 0.0222 0.548 0.598

Uncertainties are given as 2σ for 187Re/188Os and 187Os/188Os and 192Os.

The uncertainty includes the 2 SE uncertainty for mass spectrometer analysis plus uncertainties for Os blank abundance and isotopic composition.a Rho is the associated error correlation (Ludwig, 1980).b Osi = initial 187Os/188Os isotope ratio calculated at 578, 567, 575, 562 and 574 Ma.

Table S2: Re and Os elemental abundance and isotopic composition data for isochron regressions

64° 43' 10.0704" -140° 2' 30.0834"

64° 5' 36.999" -132° 13' 53.0004"

64°50'47.8026" -133°0'43.5564"

Sample Locality Lithostratigraphy Age (Ma) ± 2s analytical ± 2s total Age Type Radiometric age details Reference

17SWART7 ash 6 volcanic ash bedSwartkloofberg section, Witputs Subbasin, Nama Basin, southern Namibia Nomtsas Fm, Nama Group 538.58 ± 0.19 ± 0.63 206Pb/238U

Three of nine concordant single grain zircon analyses (excluding six older grains) combined to produce a weighted mean 206Pb/238U age, utilizing CA-TIMS and the EARTHTIME 535 spike. Linneman et al., 2019

BB5 volcanic ash bed Oman (3045m depth, Birba-5 well) Ara Group, 1m above base of A4 carbonate unit 541.00 ± 0.29 ± 0.63 206Pb/238U

Eight concordant single zircon grain analyses combined to produce a weighted mean 206Pb/238Uage, utilizing CA-TIMS and the EARTHTIME 535 spike. Bowring et al., 2007

sample 1.04 volcanic ash bed Corcal, Corumbá - State of Mato Grosso do Sul, Braziltop of Tamengo Formation, Corumba Group, southern Paraguay Belt 541.85 ± 0.77 ± 0.97 206Pb/238U

Five of eleven concordant single zircon grain analyses (excluding six older grains) combined to produce a weighted mean 206Pb/238U age, utilizing CA-TIMS and the EARTHTIME 535 spike. Parry et al., 2017

sample 1.08 volcanic ash bed Corcal, Corumbá - State of Mato Grosso do Sul, Braziltop of Tamengo Formation, Corumba Group, southern Paraguay Belt 542.37 ± 0.32 ± 0.68 206Pb/238U

Four of eight concordant single zircon grain analyses (excluding 1 older and 3 younger grains) combined to produce a weighted mean 206Pb/238U age, utilizing CA-TIMS and the EARTHTIME 535 spike. Parry et al., 2017

JIN04-2 volcanic ash bedJijiawan (Jiuqunao) section, 17 km west of Maoping in Yangtze Gorges area, western Hubei Province, South China

top of Miaohe member black shale, uppermost Doushantuo Fm 551.09 ± 0.84 ± 1.02 206Pb/238U

Sample JIN04-02 yields two concordant (of ten total) single zircon grain analyses with a weighted mean 206Pb/238U age of 551.09 ± 1.02 Ma. A corroborating weighted mean 207Pb/206Pb age of 548.09 ± 2.61 Ma is obtained from all ten zircons (recalculated using the U decay constant ratio of Mattinson, 2010). Condon et al., 2005

Porto Morrinhos tuff Porto Morrinhos - State of Mato Grosso do Sul, BrazilBocaina Formation, Corumba Group, southern Paraguay Belt 555.18 ± 0.34 ± 0.70 206Pb/238U

Eight concordant single zircon grain analyses combined to produce a weighted mean 206Pb/238U age, utilizing CA-TIMS and the EARTHTIME 535 spike. Parry et al., 2017

volcanic ash bed, sample NoP-0.9 North Point, St. Mary's Bay, Avalon Peninsula, Newfoundlandpost-glacial strata; basal Drook Formation, 0.9 m above the Gaskiers Formation; Conception Group 579.88 ± 0.52 ± 0.81 206Pb/238U

Five single zircon grains combined to produce a weighted mean 206Pb/238U age, utilizing CA-TIMS and the EARTHTIME 535 spike. Pu et al., 2016

7527 volcanic ash bedWangjiagou section in the Zhangcunping area, Yichang, Hubei Province, South China

between beds 3 and 4, below erosional unconformity in middle Doushantuo Fm 614.00 ± 9.00 ± 9.00 206Pb/238U

SHRIMP II ion probe analyses of 18 zircon grains yield a weighted mean 206Pb/238 age of 614.0 ± 9.0 Ma, (95% conf. int. including geologic scatter and an assumed 1% error in the TEMORA standardization). Liu et al., 2009

SpB Mackenzie Mountains, NW CanadaSheepbed Formation, 0.9m above contact with Hayhook Limestone Formation 632.30 ± 3.4 ± 5.9 187Re-187Os

Re-Os isochron age from organic-rich carbonaceous mudstones. Regressed using Isoplot V4.15 and includes the uncertainty in the 187Re decay constant from the Smoliar et al. (1996) paper Rooney et al., 2015

YG04-2 volcanic ash bedJijiawan (Jiuqunao) section, 17 km west of Maoping in Yangtze Gorges area, western Hubei Province, South China

9.5m above base of Doushantuo Fm, 5m above top of Lower Dolomite Member (Nantuo Cap Carbonate) 632.48 ± 0.84 ± 1.02 206Pb/238U

Three concordant (of nine total) single zircon grain analyses have a weighted mean 206Pb/238U age of 632.48 ± 1.02 Ma. A corroborating weighted mean 207Pb/206Pb age of 629.97 ± 2.83 Ma is obtained from all nine zircons (recalculated using the U decay constant ratio of Mattinson, 2010). Condon et al., 2005

YG04-15 volcanic ash bedWuhe-Gaojiaxi section, south of Sandouping in Yangtze Gorges area, western Hubei Province, South China

2.3m above base of Doushantuo Fm, within the Lower Dolomite Member (cap carbonate) 635.26 ± 0.84 ± 1.07 206Pb/238U

Three concordant (of 18 total) single zircon grain analyses have a weighted mean 206Pb/238U age of 635.26 ± 1.07 Ma. A corroborating weighted mean 207Pb/206Pb age of 632.85 ± 2.82 Ma is obtained from 11 zircons (recalculated using the U decay constant ratio of Mattinson, 2010). Condon et al., 2005

Table S3: Geochronological data for Figure 3