site u1312-u1315 methods - iodp publications

Proc. IODP | Volume 303/306

Channell, J.E.T., Kanamatsu, T., Sato, T., Stein, R., Alvarez Zarikian, C.A., Malone, M.J., and the Expedition 303/306 ScientistsProceedings of the Integrated Ocean Drilling Program, Volume 303/306

Site U1312–U1315 methods1

Expedition 306 Scientists2

Chapter contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Lithostratigraphy. . . . . . . . . . . . . . . . . . . . . . . . 3

Biostratigraphy . . . . . . . . . . . . . . . . . . . . . . . . . 7

Paleomagnetism . . . . . . . . . . . . . . . . . . . . . . . 10

Stratigraphic correlation. . . . . . . . . . . . . . . . . 11

Geochemistry . . . . . . . . . . . . . . . . . . . . . . . . . 14

Physical properties . . . . . . . . . . . . . . . . . . . . . 16

Downhole measurements . . . . . . . . . . . . . . . . 19

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

1Expedition 306 Scientists, 2006. Site U1312–U1315 methods. In Channell, J.E.T., Kanamatsu, T., Sato, T., Stein, R., Alvarez Zarikian, C.A., Malone, M.J., and the Expedition 303/306 Scientists. Proc. IODP, 303/306: College Station TX (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.303306.110.20062Expedition 306 Scientists’ addresses.

IntroductionSite locations

At all Expedition 306 sites, Global Positioning System (GPS) coor-dinates from precruise site surveys were used to position the ves-sel on site. The only seismic system used during the cruise was the3.5 kHz profiler, which was monitored on the approach to eachsite to compare the seismic characteristics of the sediments withthose from the precruise survey. Once the vessel was positioned ata site, the thrusters were lowered and a reference beacon was de-ployed. Although the automated stationkeeping system of thevessel usually uses GPS data, the beacon provides a backup refer-ence in case of problems with the transmission of satellite data.The final site position was the mean position calculated from theGPS data collected over the time that the site was occupied.

Drilling operationsThe advanced piston corer (APC) was the only coring system usedduring Expedition 306. The APC is a “cookiecutter” type systemthat cuts soft sediment cores with minimal coring disturbance rel-ative to other Integrated Ocean Drilling Program (IODP) coringsystems. The drill pipe is pressured up until the failure of twoshear pins that hold the inner barrel attached to the outer barrel.The inner barrel advances into the formation and cuts the core.The driller can detect a successful cut, or “full stroke,” from thepressure gauge on the rig floor.

The standard bottom-hole assembly (BHA) used at all Expedition306 sites comprised an 11 inch rotary bit, a bit sub, a seal boredrill collar, a landing saver sub, a modified top sub, a modifiedhead sub, a nonmagnetic drill collar, four 8¼ inch drill collars, atapered drill collar, six joints of 5½ inch drill pipe, and one cross-over sub. A lockable float valve was used instead of the standardfloat assembly if the possibility of logging existed. APC refusal isconventionally defined in two ways: (1) the piston fails to achievea complete stroke (as determined from the pump pressure read-ing) because the formation is too hard and (2) excessive force (>60klb) is required to pull the core barrel out of the formation. In thecase where full or partial stroke can be achieved but excessiveforce cannot retrieve the barrel, the core barrel can be “drilledover” (i.e., after the inner core barrel is successfully shot into theformation, the rotary bit is advanced to total depth to free theAPC barrel). This strategy allows a hole to be advanced much far-

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Expedition 306 Scientists Site U1312–U1315 methods

ther with the APC, the preferred coring tool. Non-magnetic core barrels were used during all conven-tional APC coring. When utilizing the drillovertechnique, standard steel core barrels were used be-cause they are more robust.

Each cored interval was ~9.5 m long, which is thelength of a core barrel. In some cases, the drill stringwas drilled or “washed” ahead without recoveringsediments to advance the drill bit to a target depthwhere core recovery needed to be resumed. Such ad-vances were necessary in multiple holes at a site toensure that coring gaps in one hole were covered bycored intervals in adjacent holes. The amount of ad-vance was typically 1–4 m and accounted for drillingdepth shift caused by tides, heave, and other factors(see also “Stratigraphic correlation”). Drilled andcored intervals are referred to in meters below rigfloor (mbrf), which is measured from the dual eleva-tor stool (DES) on the rig floor to the bottom of thedrill pipe. In cases where sediments of substantialthickness cover the seafloor (as at all sites during Ex-pedition 306), the mbrf depth of the seafloor is de-termined with a mudline core, assuming 100% re-covery for the cored interval in the first core. If thefirst core recovered a full barrel of sediment (it prob-ably “missed the mudline”), the seafloor referencedepth of a previous or later hole was used. Waterdepth was calculated by subtracting the distance be-tween the DES and sea level (typically 10–11 m, de-pending on the ship’s load at a given time) from thembrf depth. The water depth determined from thisdrill string measurement usually differs from preci-sion depth recorder measurements by a few to sev-eral meters. The meters below seafloor (mbsf) depthsof core tops are calculated by subtracting the seafloordepth in mbrf from the core top depth in mbrf. Thecore-top datums from the driller are the ultimatedepth reference for any further depth calculationprocedures.

Core handling and analysisAs soon as cores arrived on deck, headspace sampleswere taken using a syringe for immediate hydrocar-bon analysis as part of the shipboard safety and pol-lution prevention program. Core catcher sampleswere taken for biostratigraphic analysis. When thecore was cut in sections, whole-round samples weretaken for shipboard interstitial water examinations.In addition, headspace gas samples were immedi-ately taken from the ends of cut sections and sealedin glass vials for light hydrocarbon analysis.

Before splitting, whole-round core sections were runthrough the multisensor track (MST) and thermalconductivity measurements were taken. In addition,most whole cores were run through a “Fast Track”


magnetic susceptibility core logger (MSCL) equippedwith two magnetic susceptibility loops to facilitatereal-time drilling decisions to maximize stratigraphicoverlap between holes (see “Stratigraphic correla-tion”). The cores were then split into working andarchive halves, from bottom to top, so investigatorsshould be aware that older material could have beentransported upward on the split face of each section.The working half of each core was sampled for bothshipboard analysis (i.e., physical properties, carbon-ate, and bulk X-ray diffraction [XRD] mineralogy)and shore-based studies. Shipboard sampling waskept at a minimum during Expedition 306 to allowconstruction of a detailed sampling plan after thecomposite section was built. The archive-half sec-tions were scanned on the digital imaging system(DIS), measured for color reflectance on the archivemultisensor track (AMST), described visually and bymeans of smear slides, run through the cryogenicmagnetometer, and finally photographed with colorfilm a whole core at a time. Digital close-up photo-graphs were taken of particular features for illustra-tions in site summary reports, as requested by scien-tists. Both halves of the core were then put intolabeled plastic tubes, sealed, and transferred to coldstorage space aboard the ship. At the end of the ex-pedition, the cores were transferred from the shipinto refrigerated trucks and then to cold storage atthe IODP Bremen Core Repository in Bremen, Ger-many.

Curatorial procedures and sample depth calculations

Numbering of sites, holes, cores, and samples fol-lowed the standard IODP procedure. A full curatorialidentifier for a sample consists of the following in-formation: expedition, site, hole, core number, coretype, section number, and interval in centimetersmeasured from the top of the core section. For exam-ple, a sample identification of “306-U1312A-1H-1,10–12 cm” represents a sample removed from the in-terval between 10 and 12 cm below the top of Sec-tion 1 of Core 1 (“H” designates that this core wastaken with the APC system) of Hole U1312A duringExpedition 306. The “U” preceding hole numbers in-dicates the hole was drilled by the United States Im-plementing Organization (USIO) platform. Cored in-tervals are also referred to in “curatorial” mbsf. Thembsf of a sample is calculated by adding the depth ofthe sample below the section top and the lengths ofall higher sections in the core to the core-top datummeasured with the drill string. A soft to semisoft sed-iment core from less than a few hundred meters be-low seafloor expands upon recovery (typically a fewpercent to as much as 15%), so the recovered interval

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does not match the cored interval. In addition, a cor-ing gap typically occurs between cores, as shown bycomposite depth construction (i.e., some cored inter-val was lost during recovery or was never cut) (see“Stratigraphic correlation”). Thus, a discrepancyexists between the drilling mbsf and the curatorialmbsf. For instance, the curatorial mbsf of a sampletaken from the bottom of a core is deeper than thatfrom a sample from the top of the subsequent core,where the latter does correspond to the drilled core-top datum. During Expedition 306, multiple APCholes (typically three) were drilled at a site to con-struct a continuous composite section. This resultedin a meters composite depth (mcd) scale for each sitethat accommodates core expansion and drilling gapsthrough interhole correlation of closely spaced mea-surements of core physical properties (see “Strati-graphic correlation”).

LithostratigraphyThis section outlines the procedures used todocument the basic sedimentology of the depositsrecovered during Expedition 306, including visualcore description, smear slide description, digitalcolor imaging, color spectrophotometry, and XRDstudies. For consistency of Expedition 303 and 306sediment classifications, the procedures described inthe “Site U1302–U1308 methods” chapter weremainly followed. Only general procedures areoutlined, except where they depart significantlyfrom Ocean Drilling Program (ODP) and IODPconventions.

Sediment classificationThe sediments recovered during Expedition 306 werecomposed of biogenic and siliciclastic components.They were described using the classification schemeof Mazzullo et al. (1988). The biogenic component iscomposed of the skeletal debris of open-marine cal-careous and siliceous microfauna (e.g., foraminifersand radiolarians, respectively) and microflora (e.g.,calcareous nannofossils and diatoms, respectively)and associated organisms. The siliciclastic compo-nent is composed of mineral and rock fragments de-rived from igneous, sedimentary, and metamorphicrocks. The relative proportions of these two compo-nents are used to define the major classes of “granu-lar” sediments in the scheme of Mazzullo et al.(1988).

The lithologic names assigned to these sedimentsconsist of a principal name based on composition,degree of lithification, and/or texture as determinedfrom visual description of the cores and from smearslide observations. The total calcium carbonate


content of the sediments, determined on board (see“Geochemistry”), was also used to aid inclassification. For a sediment that is a mixture ofcomponents, the principal name is preceded bymajor modifiers (in order of increasing abundance)that refer to components making up ≥25% of thesediment. Minor components that representbetween 10% and 25% of the sediment follow theprincipal name (after a “with”) in order of increasingabundance. Minor sedimentary components <10%in abundance are not reflected in the lithologicname. For example, an unconsolidated sedimentcontaining 30% nannofossils, 50% clay minerals,15% foraminifers, and 5% quartz would be describedas a nannofossil clay with foraminifers. For biogenicsediments (i.e., >50% biogenic grains; see below),major or minor modifiers of siliciclastic componentswere summed, resulting in a more inclusive/generalterm for the name of the sediment. For example, anunconsolidated sediment containing 55%nannofossils, 15% foraminifers, 10% clay minerals,10% quartz, and 10% detrital calcite would bedescribed as a silty clay nannofossil ooze withforaminifers. Minor sedimentary components arenot designated in the Graphic Lithology column ofthe barrel sheets.

These naming conventions follow the ODP sedimentclassification scheme (Mazzullo et al., 1988), withthe exception that during Expedition 306 a separate“mixed sediment” category was not distinguished(Fig. F1). As a result, biogenic sediments are thosethat contain >50% biogenic grains and <50%siliciclastic grains, whereas siliciclastic sediments arethose that contain >50% siliciclastic grains and<50% biogenic grains. For the classification ofbiogenic carbonate oozes, three categories were used:

• Foraminifer ooze (content of foraminifers>50%).

• Nannofossil ooze (content of nannofossils>50%).

• Calcareous ooze (content of nannofossils + for-aminifers >50%, but content of nannofossils<50% and content of foraminifers <50%).

Some sediments contained >50% biogeniccomponents, but no single biogenic component was>50%. In these instances, the siliceous and calcareouscomponents were summed, resulting in a lithologicname that reflects the relative contribution of eachbiogenic component by listing these components inorder of increasing abundance. For example, anunconsolidated sediment containing 45%nannofossils, 15% diatoms, 10% sponge spicules,10% clay minerals, 10% quartz, and 10% detritalcalcite would be described as a silty clay biosiliceous-nannofossil ooze.

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Size divisions for siliciclastic grains are those ofWentworth (1922) (Fig. F2), with 10 major texturalcategories defined on the basis of the relativeproportions of sand, silt, and clay (Fig. F3); however,distinguishing between some of these categories isdifficult (e.g., silty clay versus clayey silt) withoutaccurate measurements of grain size abundances. Forsiliciclastic sediments, the term “clay” is only used todescribe particle size and is applied to both clayminerals and other siliciclastic/detrital mineralcomponents <4 µm in size. Size-textural qualifierswere not used for biogenic sediment names (e.g.,nannofossil clay implies that the dominantcomponent is detrital clay rather than clay-sizednannofossils).

During Expedition 306, neritic and chemical sedi-ments were not encountered except as accessorycomponents; therefore, these categories are not ad-dressed below. Sediments containing >50% silt- andsand-sized volcanic grains were classified as ash lay-ers.

Terms that describe lithification vary dependingupon the dominant composition as described below:

• Sediments composed predominantly of calcareouspelagic organisms (e.g., nannofossils and foramini-fers): the lithification terms “ooze” and “chalk”reflect whether the sediment can be deformed witha finger (ooze) or can be scratched easily by a fin-gernail (chalk).

• Sediments composed predominantly of siliceousmicrofossils (diatoms, radiolarians, and siliceoussponge spicules): the lithification terms “ooze” and“diatomite/radiolarite/spiculite” reflect whether thesediment can be deformed with a finger (ooze) orcannot be easily deformed manually (diatomite/radiolarite/spiculite).

• Sediments composed predominantly of siliciclasticmaterial: if the sediment can be deformed easilywith a finger, no lithification term is added, andthe sediment is named for the dominant grain size(e.g., “clay”). For more consolidated material, thelithification suffix “-stone” is appended to thedominant size classification (e.g., “claystone”).

• Sediments composed of sand-sized volcaniclasticgrains: if the sediment can be deformed easily witha finger, the interval is described as ash. For moreconsolidated material, the rock is called tuff.

Visual core descriptionPreparation for core descriptionThe standard method of splitting a core by pulling awire lengthwise through its center tends to smearthe cut surface and obscure fine details of lithologyand sedimentary structure. When necessary during


Expedition 306, the archive halves of cores were gen-tly scraped across, rather than along, the core sectionusing a stainless steel or glass scraper to prepare thesurface for unobscured sedimentologic examinationand digital imaging. Scraping parallel to beddingwith a freshly cleaned tool prevented cross-stratigraphic contamination.

Sediment barrel sheetsCore description forms, or “barrel sheets,” provide asummary of the data obtained during shipboardanalysis of each sediment core. Detailed observationsof each section were recorded initially by hand onstandard IODP visual core description (VCD) forms.Copies of original VCD forms are available fromIODP upon request. This information wassubsequently entered into AppleCORE (version 9.4),which generates a simplified annotated graphicaldescription (barrel sheet) for each core (Fig. F4). Site,hole, and depth (in mbsf or mcd if available) aregiven at the top of the barrel sheet, with thecorresponding depths of core sections along the leftmargin. Columns on the barrel sheets includeGraphic Lithology, Bioturbation, Structures,Accessories, Sediment Disturbance, Sample Types,Color, and Description. These columns are discussedin more detail below.

Graphic lithology

Lithologies of the core intervals recovered arerepresented on barrel sheets by graphic patterns inthe Graphic Lithology column using the symbolsillustrated in Figure F5. A maximum of two differentlithologies (for interbedded sediments) or threedifferent components (for a uniform sediment) canbe represented within the same core interval. Minorlithologies, present as thin interbeds within themajor lithology, are shown by a dashed vertical linedividing the lithologies. Lithologic abundances arerounded to the nearest 10%. Lithologies thatconstitute <25% of the core are generally not shownbut are listed in the Lithologic Description section.However, some distinctive minor lithologies, such asash layers, are included graphically in the lithologycolumn. Contact types (e.g., sharp, scoured,gradational, and bioturbated) are also shown in theGraphic Lithology column. Relative abundances oflithologies reported in this way are useful for generalcharacterization of the sediment but do notconstitute precise, quantitative observations.

Bioturbation

For bioturbation classification, five levels ofbioturbation were used during Expedition 306. Theselevels are illustrated with graphic symbols in the

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Bioturbation column (Fig. F6), and are presented in ascheme based on Droser and Bottjer (1986) (Fig. F7).Bioturbation intensity is classified as:

• Strong (>50%),• Moderate (10%–50%),• Rare (<10%), and• Absent (no bioturbation).

Most of the Expedition 306 sediments fall into oneof these four categories. As a fifth category, theclassification “homogeneous” occasionally was usedto represent a totally bioturbated or homogenizedsediment. Note, however, that in a homogeneoussediment section with no color changes at all it isoften not clearly possible to estimate the degree ofbioturbation, which may range from absent tototally bioturbated or homogenized.

Sedimentary structures

The locations and types of sedimentary structuresvisible on the prepared surfaces of the split cores areshown in the Structure column of the coredescription form using the symbols represented inFigure F6. Symbols in this column indicate thelocations of individual bedding features and anyother sedimentary features, such as scours, ashlayers, ripple laminations, and fining-upward orcoarsening-upward intervals.

Accessories

Lithologic, diagenetic, and paleontologic accessories,such as nodules, sulfides, and shells, are indicated inthe Accessories column on the barrel sheets. Thesymbols used to designate these features are shownin Figure F6.

Sediment disturbance

Drilling-related sediment disturbance that persistsover intervals of ~20 cm or more is recorded in theDisturbance column using the symbols shown inFigure F6. The degree of drilling disturbance is de-scribed for soft and firm sediments using the follow-ing categories:

• Slightly disturbed: bedding contacts are slightlydeformed.

• Moderately disturbed: bedding contacts haveundergone extreme bowing.

• Extremely disturbed: bedding is completelydeformed as flow-in, coring/drilling slurry, andother soft-sediment stretching and/orcompressional shearing structures attributed tocoring/drilling. The particular type of deformationmay also be noted (e.g., flow-in, gas expansion,etc.).


• Soupy: intervals are water saturated and have lostall aspects of original bedding.

Sample types

Sample material taken for shipboard sedimentologicand chemical analysis consisted of pore water wholerounds, micropaleontology samples, smear slides,and discrete samples for XRD. Typically, one to fivesmear slides were made per core, one pore watersample was taken at a designated interval, and amicropaleontology sample was obtained from thecore catcher of most cores. XRD samples were takenonly where needed to assess the lithologiccomponents. Additional samples were selected tobetter characterize lithologic variability within agiven interval. Tables summarizing relativeabundance of sedimentary components from thesmear slides were generated using a spreadsheet ex-ported from a standard program (Sliders) used duringthe cruise.

Color

Color is determined qualitatively using Munsell SoilColor Charts (Munsell Color Company, 1994) anddescribed immediately after cores are split to avoidcolor changes associated with drying and redoxreactions. When portions of the split core surfacerequired cleaning with a stainless steel or glassscraper, this was done prior to determining the color.Munsell color names are provided in the Colorcolumn on the barrel sheet, and the correspondinghue, value, and chroma data are provided in the De-scription column.

Description

The written description for each core contains a briefoverview of both major and minor lithologiespresent and notable features such as sedimentarystructures and disturbances resulting from the coringprocess.

Smear slidesSmear slide samples were taken from the archivehalves during core description. For each sample, asmall amount of sediment was removed with awooden toothpick, dispersed evenly in deionizedwater on a 1 inch × 3 inch glass slide, and dried on ahot plate at a low setting. A drop of mounting me-dium and a 1 inch × 1 inch cover glass was added,and the slide was placed in an ultraviolet light boxfor ~30 min. Once fixed, each slide was scanned at100×–200× with a transmitted light petrographic mi-croscope using an eyepiece micrometer to assessgrain-size distributions in clay (<4 µm), silt (4–63µm), and sand (>63 µm) fractions. The eyepiece mi-

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crometer was calibrated once for each magnificationand combination of ocular and objective using aninscribed stage micrometer.

Relative proportions of each grain size and type wereestimated by microscopic examination. Note thatsmear slide analyses tend to underestimate theabundance of sand-sized and larger grains (e.g.,foraminifers, radiolarians, and siliciclastic sand)because these are difficult to incorporate into thesmear. Clay-sized biosilica, being transparent andisotropic, is also very difficult to quantify. Clayminerals, micrite, and nannofossils can also bedifficult to distinguish at the very finest (less than ~4µm) size range. After scanning for grain-sizedistribution, several fields were examined at 200×–500× for mineralogical and microfossilidentification. Standard petrographic techniqueswere employed to identify the commonly occurringminerals and biogenic groups as well as importantaccessory minerals and microfossils.

Smear slide analysis data tables are included in“Core descriptions.” These tables includeinformation about the sample location, whether thesample represents a dominant (D) or a minor (M)lithology in the core, and the estimated percentagesof sand, silt, and clay together with all identifiedcomponents. Relative abundances of different graintypes below 5% were assigned on a semiquantitativebasis using the following abbreviations: tr = trace(0%–1%), and R = rare (1%–5%).

Abundance of gravel-sized grainsOne of the primary objectives of Expeditions 303and 306 was to collect cores that record thepaleoclimatic history of the North Atlantic atmillennial and longer timescales. Because of thegeographic location and the geologic age of thesesediments, ice-rafted debris (IRD) was expected to bean important part of that paleoclimatic record. Themost easily identified IRD consists of outsized clastsin a fine-grained pelagic matrix and is often definedoperationally as gravel-sized grains. DuringExpedition 306, the abundance of IRD was estimatedby counting the number of gravel-sized grains (i.e.,granule size and larger) in each 1 cm increment ofthe core. Wherever possible, composition, size, andangularity of each clast were also determined. All ofthis information is recorded in a table within eachsite chapter.

Spectrophotometry (color reflectance)Reflectance of visible light from the surface of splitsediment cores was routinely measured using aMinolta spectrophotometer (model CM-2002)


mounted on the AMST. The AMST measures thearchive half of each core section and provides ahigh-resolution stratigraphic record of colorvariations for visible wavelengths (400–700 nm).Freshly split soft cores were covered with clear plasticwrap and placed on the AMST. Measurements weretaken at 2.0 cm spacing. The AMST skips emptyintervals and intervals where the core surface is wellbelow the level of the core liner but does not skiprelatively small cracks, disturbed areas of core, orlarge clasts. Thus, AMST data may contain spuriousmeasurements, which should be edited out of thedata set. Each measurement recorded consists of 31separate determinations of color reflectance in 10nm wide spectral bands from 400 to 700 nm.Additional detailed information about measurementand interpretation of spectral data with the Minoltaspectrophotometer can be found in Balsam et al.(1997, 1998) and Balsam and Damuth (2000).

Digital color imagingSystematic high-resolution line scan digital coreimages of the archive half of each core were obtainedusing the Geotek X-Y DIS (Geoscan II). This DIScollects digital images with three line-scan charge-coupled device arrays (1024 pixels each) behind aninterference filter to create three channels (red,green, and blue). The image resolution is dependenton the width of the camera and core. The standardconfiguration for the Geoscan II produces 300 dpi onan 8 cm wide core with a zoom capability up to 1200dpi on a 2 cm wide core. Synchronization and trackcontrol are better than 0.02 mm. The dynamic rangeis 8 bits for all three channels. The FrameStore cardhas 48 MB of onboard random-access memory forthe acquisition of images with an Industry StandardArchitecture interface card for personal computers.After cores were visually described, they were placedin the DIS and scanned. A spacer holding a neutralgray color chip and a label identifying the sectionwas placed at the base of each section and scannedalong with each section. Output from the DISincludes a Windows bitmap (.BMP) file and a JPEG(.JPEG, .JPG) file for each section scanned. Thebitmap file contains the original data. Additionalpostprocessing of data was done to achieve amedium-resolution JPEG image of each section and acomposite JPEG image of each core, which iscomparable to the traditional photographic image ofeach core. The JPEG image of each section wasproduced by an Adobe Photoshop batch job thatopened the bitmap file, resampled the file to a widthof 0.6 inch (~15 mm) at a resolution of 300 pixels/inch, and saved the result as a maximum-resolutionJPEG. The DIS was calibrated for black and white

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approximately every 12 h. No significant change inthis calibration was observed during Expedition 306.A constant aperture setting of f/11 was used.

X-ray diffraction analysisSelected samples were taken for qualitative mineralanalysis by using an XRD Philips model PW1729 X-ray diffractometer using Ni-filtered CuKα radiation.Instrument conditions were as follows: 40 kV, 35mA; goniometer scan from 2° to 70°2θ (air-driedsamples) and from 2° to 12°2θ (glycolated samples);step size = 0.01°2θ; scan speed = 1.2°2θ/min; andcount time of 0.5 s. Some samples were decalcifiedusing 10% acetic acid then washed repeatedly withdemineralized water in a centrifuge. The carbonate-free fraction was deflocculated with a 1% Calgon(sodium hexametaphosphate) solution andhomogenized in a sonic dismembrator for 1 min.MacDiff software (version 4.1.1 PPC by RainerPetschick) was used to display diffractograms, andidentifications are based on multiple peak matchesusing the mineral database provided with MacDiff.Diffractograms were peak corrected to match thecalcite peak at 3.035 Å. In the absence of calcite, nopeak correction was applied.

BiostratigraphyPreliminary ages were assigned primarily based oncore catcher samples. Samples from within the coreswere examined when a more refined age determina-tion was necessary. Ages for calcareous nannofossil,foraminifer, diatom, and radiolarian events from thelate Miocene–Quaternary were estimated by correla-tion to the geomagnetic polarity timescale (GPTS) ofCande and Kent (1995). The biostratigraphic events,zones, and subzones for nannofossils, planktonicforaminifers, diatoms, and radiolarians are summa-rized in Figure F8. The Pliocene/Pleistocene bound-ary has been formally located just above the top ofthe Olduvai (C2n) magnetic polarity subchronozone(Aguirre and Pasini, 1985) and just below the lowestoccurrence of Gephyrocapsa caribbeanica at 1.73 Ma(Takayama and Sato, 1993–1995). Gephyrocapsa spe-cies occur in upper Pliocene sediments; however,medium-sized forms (>4 µm) first appear just abovethe Pliocene/Pleistocene boundary (de Kaenel et al.,1999), coincident with the lowest occurrence of G.caribbeanica (Takayama and Sato, 1993–1995; Sato etal., 1999). Thus, we define G. caribbeanica and Ge-phyrocapsa oceanica as specimens >4 µm to distin-guish between Pliocene and Pleistocene forms. Inaddition, the first occurrences (FOs) of Globorotaliatruncatulinoides and Globorotalia inflata at 2.09 Maimmediately below the Olduvai subchronozone is


very useful to approximate the Neogene/Quaternaryboundary. Thus for this study, we locate thePliocene/Pleistocene boundary between the FO of G.caribbeanica (>4 µm) and the FOs of G. truncatuli-noides and G. inflata.

The Miocene/Pliocene boundary has not yet beenformally defined. Its location is not well constrainedbecause no biostratigraphic event has been identifiedin this interval of time; however, the last occurrence(LO) of Discoaster quinqueramus is at 5.5 Ma and theFO of Thalassiosira convexa is between 6.1 and 6.4Ma.

Details of the shipboard methods are described be-low for each microfossil group.

Calcareous nannofossilsThe zonal scheme established by Martini (1971) wasused for Miocene–Quaternary sequences during Ex-pedition 306. In addition, the late Pliocene–Quaternary biostratigraphic horizons defined bySato et al. (1999) were used for more detailed correla-tions. Correlation of the zonal scheme and biostrati-graphic horizons to the GPTS of Cande and Kent(1995) is shown in Figure F8. Age estimates for da-tums tied to the geomagnetic timescale are alsoshown in Figure F8 and listed in Table T1.

MethodsSamples were prepared utilizing standard smear slidemethods with Norland optical adhesive as a mount-ing medium. Calcareous nannofossils were exam-ined with a Zeiss light microscope at 1250× magnifi-cation using cross-polarized light, transmitted light,and phase contrast light.

We followed the taxonomic concepts summarized inTakayama and Sato (1987; Deep Sea Drilling Project[DSDP] Leg 94). Calcareous nannofossil preservationwas assessed as follows:

G = good (little or no evidence of dissolution orovergrowth, little or no alteration of primarymorphological features, and specimens areidentifiable to the species level).

M = moderate (minor dissolution or crystal over-growth observed, some alteration of primarymorphological features, but most specimensare identifiable to the species level).

P = poor (strong dissolution or crystal over-growth, significant alteration of primary mor-phological features, and many specimens areunidentifiable at the species and/or genericlevel).

The total abundance of calcareous nannofossils foreach sample was estimated as follows:

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V = very abundant (>100 specimens per field ofview [FOV]).

A = abundant (11–100 specimens per FOV).C = common (1–10 specimens per FOV).F = few (1 specimen per 2–10 FOVs).R = rare (1 specimen per 11 or more FOVs).B = barren.

Nannofossil abundances of individual species wererecorded as follows:

A = abundant (11 or more specimens per FOV).C = common (1–10 specimens per FOV).F = few (1 specimen per 2–10 FOVs).R = rare (1 specimen per 11 or more FOVs).P = present, but abundance was not quantita-

tively determined.? = questionable occurrence.* = reworked occurrence.

ForaminifersPreliminary ages were assigned based on the occur-rence of planktonic foraminifers from core catchersamples. Stratigraphic events of Weaver and Clement(1987) for the North Atlantic and Lourens et al.(1996) for the Mediterranean were applied to thePliocene and Pleistocene samples of Expedition 306(Fig. F8). For the late Miocene, however, planktonicforaminiferal events as defined by Sierro et al. (1993,2001), Krijgsman et al. (1995), and Hilgen et al.(2000) for the northeast Atlantic and MediterraneanSea were used (Table T2). Middle Miocene stratig-raphy is based on Spezzaferri (1998). The speciesidentified as Globorotalia cf. crassula by Weaver andClement (1987) has a highly convex dorsal side,which led us to relate this species to Globorotalia hir-suta during Expedition 306. Consequently, only G.hirsuta is listed in the tables and the LO of G. cf. cras-sula, dated at 3.18 Ma by Weaver and Clement(1987), is renamed to “disappearance of G. hirsuta.”Globorotalia conomiozea and Globorotalia miotumidahave been grouped together as the G. miotumidagroup. For the abundance estimates, Neogloboquad-rina acostaensis is combined with Neogloboquadrinapachyderma, and in the Miocene the Globorotalia me-nardii group also includes Globorotalia plesiotumidaand Globorotalia merotumida following Sierro et al.(1993). Otherwise, taxonomic concepts for Neogenetaxa are adopted from Kennett and Srinivasan(1983). The magnetic stratigraphy for the Cenozoicis derived from Cande and Kent (1995).

The benthic foraminifers are defined by assemblagezones. Boundaries are placed at major shifts in thefauna. Each zone is named after its dominant spe-cies. Benthic foraminifers provide limited biostrati-graphic age control as currently applied to Expedi-tion 306 samples. Whenever possible, the genus


Stilostomella was used as a marker because most of itsspecies disappeared from the global ocean at differ-ent latitudes during the interval of 1.0–0.6 Ma (Hay-ward, 2001). Taxonomic assignments on the genericlevel follow Loeblich and Tappan (1988). Benthicforaminifers were identified mainly to determinepast changes in oceanographic conditions and sur-face water productivity. Oxygenation and carbonflux are the main factors controlling abundance andspecies composition in deep-sea assemblages (Joris-sen et al., 1995; Altenbach et al., 2003).

During the benthic assemblage analysis, the pres-ence or absence of ostracodes was noted, as they willbe used for postcruise paleoceanographic studies.

MethodsFrom each core catcher, 20 cm3 of sediment was ana-lyzed for planktonic and benthic foraminifers. Un-lithified sediment samples were soaked in tap waterand then washed over a 63 µm sieve. Semilithifiedmaterial was soaked in a 3% H2O2 solution beforewashing. Washed samples were dried at 60°C and an-alyzed under a ZEISS Stemi SV11 or ZEISS DR binocu-lar microscope. The residue was split, with three-quarters of the sample being used for the benthicand one-quarter for the planktonic foraminifersanalysis. Sieves for wet sieving were cleaned in a son-icator for several minutes and for dry sieving wereblown out with compressed air to avoid contamina-tion between successive samples.

Planktonic foraminifer abundance in the fraction>125 µm in relation to the total residue was catego-rized as follows:

D = dominant (>30%).A = abundant (10%–30%).F = few (5%–10%).R = rare (1%–5%).P = present (<1%).B = barren.

Benthic foraminifer abundance in a sample of the>63 µm size fraction is registered as follows:

D = dominant (>30%).A = abundant (10%–30%).F = few (5%–10%).R = rare (1%–5%).P = present (<1%).B = barren.

Preservation includes the effects of diagenesis, epi-genesis, abrasion, encrustation, and/or dissolution.Preservation of planktonic and benthic species wascategorized as follows:

VG = very good (no evidence of breakage or disso-lution).

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G = good (dissolution effects are rare; >90% ofspecimens unbroken).

M = moderate (dissolution damages, such asetched and partially broken tests, occur fre-quently; 30%–90% of specimens unbroken).

P = poor (strongly recrystallized or dominated byfragments or corroded specimens).

DiatomsExcept for previous Leg 94 and ODP Leg 162, diatomdata from the mid-latitude North Atlantic Ocean aresparse, and only a few diatom biostratigraphic stud-ies have been completed. The Neogene and Quater-nary diatom zonation used for the high-latitude sitesof Expedition 306 is that proposed by Baldauf (1984)and Koç et al. (1999). The late Miocene–Holoceneportion of this zonation is based on the occurrencein the North Atlantic of a warm-temperature diatomassemblage similar to that recorded from the easternequatorial Pacific (Burckle, 1972, 1977; Baldauf,1984; Barron, 1985). In addition, diatom stratigra-phies from the Japan Trench (Akiba and Yanagisawa,1986), as well as from the North Pacific–Bering Searegion (Koizumi, 1971) were adopted in an attemptto cover the gap in the late Miocene–late Pliocenehigh-latitude North Atlantic diatom stratigraphy(Koç et al., 1999). This is partly justified by the rarepossible finding of Neodenticula kamtschatica duringExpedition 303 (see “Biostratigraphy” in “SiteU1302–U1308 methods”). Figure F8 lists diatom bio-stratigraphic events, paleomagnetic calibration, andage estimates used during this expedition.

Typical diatom assemblages preserved in the sedi-mentary record can be used as tracers for the corre-sponding hydrographic conditions in the surface wa-ters. Diatoms characterize fertile surface waters ofhigh latitudes and coastal upwelling areas. In theNorth Atlantic north of ~50°N, they are diverse andare the main contributors to the biogenic silica pre-served in the sediment (Baldauf, 1984; Koç et al.,1999).

MethodsTwo types of slides were prepared for diatom analysisdepending on overall abundance. For intervals ofhigh abundance, smear slides were prepared from asmall amount of raw material from the core catcher.When dictated by a low concentration of diatomvalves and/or abundant clay, selected core catchersamples were processed by boiling in a solution ofH2O2 and sodium pyrophosphate to remove organicmatter and to disperse the clay-sized material fol-lowed by treatment with HCl to remove CaCO3. Thetreated samples were then washed several times withdistilled water. In each case, aliquots of raw and


cleaned samples were mounted on microscope slidesusing Norland optical adhesive. All slides were exam-ined with illumination at 1000× magnification forstratigraphic markers and paleoenvironmentally sen-sitive taxa. The counting convention of Schrader andGersonde (1978) was adopted. Overall diatom abun-dance and species relative abundances were deter-mined based on smear slide evaluation using the fol-lowing conventions:

A = abundant (>100 valves per traverse).C = common (40–100 valves per traverse).F = few (20–40 valves per traverse).R = rare (10–20 valves per traverse).T = trace (2–9 valves per traverse).T = single occurrence or fragment per tranverse.B = barren.

For computing purposes, a number was assigned toeach abundance category (0 = B, 1 = T, 2 = R, 3 = F, 4= C, and 5 = A).

Preservation of diatoms was determined qualita-tively as follows:

G = good (weakly silicified forms present and noalteration of frustules observed).

M = moderate (weakly silicified forms present,but with some alteration).

P = poor (weakly silicified forms absent or rareand fragmented, and the assemblage is dom-inated by robust forms).

A number was assigned to each category (1 = P, 2 =M, and 3 = G).

RadiolariansThere is currently no working high-resolution radio-larian biostratigraphic framework applicable to theNorth Atlantic, but several existing sites could po-tentially be used for this matter. The stratigraphicframework established by Goll and Bjørklund (1989)is only applicable for the Norwegian Sea. Goll andBjørklund (1989) found that most radiolarians en-countered in the Norwegian Sea are endemic andthus proposed a unique biostratigraphic scheme forthat area. Lazarus and Pallant (1989) did not estab-lish a biostratigraphic zonal scheme for the LabradorSea, but as the species are clearly different from thosein the Norwegian Sea, the biostratigraphic scheme ofthe Norwegian Sea cannot be used. Thus, there is noavailable radiolarian biostratigraphic framework forthe Labrador Sea at present. On the other hand,Westberg-Smith and Riedel (1984) recognized two ra-diolarian zones, including the Stichocorys peregrinaand Sphaeropyle langii Zones, for the late Mioceneand early Pliocene in deep-sea cores from the RockallPlateau, high-latitude North Atlantic. Haslett (1994,2004) reported several radiolarian biostratigraphic

9


events throughout the Pliocene and Pleistocene atthe mid-latitude North Atlantic DSDP Site 609,which is directly comparable to this expedition.

For the above reason, we will try to apply the schemesuggested by Haslett (1994, 2004), especially for thePliocene–Pleistocene section, and Westberg-Smithand Riedel (1984) for the late Miocene and earlyPliocene. Numerical age datums were tied to theGPTS of Cande and Kent (1995). Primary datumsfrom late Miocene to Pleistocene are listed in FigureF8.

As mentioned above, radiolarians in the North At-lantic show a different faunal distribution than inthe Norwegian Sea, the Labrador Sea, and the mid-latitude North Atlantic, making it difficult to estab-lish a biostratigraphic framework in this region.However, radiolarian biostratigraphy of the NorthAtlantic will play an important role not only in a lo-cal biostratigraphic zonation, but also in the pale-oceanographic reconstruction of this area. Duringpreglacial times, oceanic conditions should havebeen more homogeneous in the North Atlantic andradiolarian associations have a better chance for amore uniform distribution. The hydrographical andecological situations are more provincial in the post-glacial period, so radiolarian associations shouldhave been endemic to specific regions. Therefore,most likely, local biostratigraphic schemes have to beestablished in the Labrador Sea, the North Atlantic,and the Norwegian Sea, respectively.

MethodsCore catcher samples were treated with a 5%–8% so-lution of HCl to dissolve all calcareous components.The solution was sieved through a 45 µm meshscreen. The residue was disaggregated by gentle boil-ing in 5%–8% H2O2 with a few grams of Calgon andsieved again. After settling in the beaker, the residuewas picked up and dropped on a slide using an eye-dropper. The sample was spread with a toothpickand dried on a hot plate. A few drops of Norland op-tical adhesive were used to apply a 22 mm × 50 mmglass coverslip.

Overall radiolarian abundances were determinedbased on slide evaluation with a 20× objective lensusing the following convention:

A = abundant (>100 specimens per traverse).C = common (51–100 specimens per traverse).F = few (11–50 specimens per traverse).R = rare (1–10 specimens per traverse).T = trace (<1 specimens per traverse).B = barren.


The abundance of individual species was recordedrelative to the fraction of the total assemblages asfollows:

A = abundant (>10% of the total assemblage).C = common (5%–10% of the total assemblage).F = few (<5% of the total assemblage).R = rare (a few or more specimens per slide).T = trace (present in slide).B = barren.

Preservation was recorded as follows:

G = good (majority of specimens complete, withminor dissolution, recrystallization, and/orbreakage).

M = moderate (minor but common dissolution,with a small amount of breakage of speci-mens).

P = poor (strong dissolution, recrystallization, orbreakage, many specimens unidentifiable).

The abundances of lithic grains, including tephraand organic compounds in the slides, were also eval-uated.

PaleomagnetismPaleomagnetic analyses during Expedition 306 con-sisted of long-core measurements of the natural re-manent magnetization (NRM) of archive-half sec-tions before and after alternating-field (AF)demagnetization. In addition, low-field volume mag-netic susceptibility was measured on whole cores us-ing the MSCL and MST devices.

NRM measurements and AF demagnetizations wereperformed using a three-axis (x, y, and z) long-corecryogenic magnetometer (2G Enterprises model 760-R). This instrument is equipped with a direct-currentsuperconducting quantum interference device (DC-SQUID) and has an inline AF demagnetizer capableof reaching peak fields of 80 mT (2G Enterprisesmodel 2G600). The spatial resolution measured bythe width at half-height of the pickup coils responseis <10 cm for all three axes, although they sense amagnetization over a core length up to 30 cm. Theeffective sensor length (i.e., area under the normal-ized SQUID response function) of axes x, y, and z are6.071, 6.208, and 9.923 cm, respectively. Experi-ments conducted during ODP Legs 186 and 206showed that the background noise level of the mag-netometer is about ±2 × 10–9 Am2 and that reliablemeasurements could be obtained for intensitiesgreater than ~10–5 A/m for split-core sections (Ship-board Scientific Party, 2000, 2003b).

Archive halves of all core sections were measured un-less precluded by drilling-related deformation. Mea-surements were made at intervals of 5 cm, starting

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15 cm above the top and ending 15 cm below thebase of each section. These additional data pointswere measured to allow deconvolution of the recordsin later shore-based studies. When performing ship-board data analyses (e.g., for site reports), data corre-sponding to the top and bottom 10 cm of each coresection were edited to account for edge effects. Thenumber of demagnetization steps used to removethe drill string magnetic overprint and isolate a use-ful magnetic moment reflected time constraints. Athree-step demagnetization scheme consisting of 0(NRM), 10, and 20 mT was used initially. When coreflow through the laboratory needed to be increased,only the first (NRM) and last (20 mT) demagnetiza-tion steps were used, reducing the measurementtime by ~5 min per core section. The use of peak AFdemagnetization fields lower than 20 mT ensure thatarchive halves remain useful for shore-based studies.

Measurements were undertaken using the standardIODP magnetic coordinate system described in Fig-ure F9 (+x = vertical upward from the split surface ofarchive halves, +y = left-hand split surface whenlooking upcore, and +z = downcore). Data werestored using the standard IODP file format. Datawere manually checked for quality, and the autosaveoption was not used. The sample interval was set to 5cm, leader and trailer lengths were both set to 15 cm,and a drift correction was applied. The program op-tions for skipping voids and gaps at the top of thesection were not used. Void depths and otherwisedisturbed intervals were instead manually noted onthe “cryomag log sheets” and later taken into ac-count. All sections were measured using an internaldiameter setting of 6.5 cm. Background tray magne-tization was measured at least once per shift (e.g., atthe beginning of each shift) and subtracted from allmeasurements.

During APC coring a nonmagnetic “monel” core bar-rel was used for all but some overdrilled parts of thesection (see “Introduction”). Full orientation was at-tempted using the Tensor orientation tool beginningat Core 3 of all holes when available. The Tensor toolis rigidly mounted onto a nonmagnetic sinker bar at-tached to the top of the core barrel assembly. TheTensor tool consists of three mutually perpendicularmagnetic field fluxgate sensors and two perpendicu-lar gravity sensors. The information from both setsof sensors allows the azimuth and dip of the hole tobe measured as well as azimuth of the APC core(Shipboard Scientific Party, 2003a). The azimuthal ref-erence line is the double orientation line on the coreliner and remains on the working half after the coreis split.

Where the shipboard AF demagnetization appears tohave isolated the characteristic remanent magnetiza-


tion, paleomagnetic inclinations and/or declinationsof the highest demagnetization step, typically 20mT, were used to define magnetic polarity zones. Therevised timescale of Cande and Kent (1995) with up-dated age estimates for the Cobb Mountain (1.190–1.215 Ma) (Channell et al., 2002) and Reunion(2.115–2.153 Ma) (Channell et al., 2003) Subchrono-zones was used as a reference for the ages of correla-tive Cenozoic polarity chrons.

The magnetic susceptibility of whole-core sectionswas measured on two separate track systems. Whole-core sections were measured on a MSCL to rapidlyacquire magnetic susceptibility data for stratigraphiccorrelation (see “Stratigraphic correlation”). Afterwhole cores warmed to room temperature, measure-ments were made as part of the MST analyses (see“Physical properties”).

Stratigraphic correlationPaleomagnetic and paleoclimatic objectives of Expe-dition 306 required the recovery of complete strati-graphic sections, yet stratigraphers have demon-strated that a continuous section is rarely recoveredfrom a single ODP borehole because of core-recoverygaps between successive APC and extended core bar-rel cores despite 100% or more nominal recovery(Ruddiman et al., 1987; Hagelberg et al., 1995). Con-struction of a complete section, referred to as a com-posite splice, requires combining stratigraphic inter-vals from two or more holes cored at the same site.To maximize the probability of bridging core-recovery gaps in successive holes, the depths belowthe seafloor from which cores are recovered are offsetbetween the holes. This practice ensures that mostbetween-core intervals missing within a given holeare recovered in at least one of the adjacent holes.During Expedition 306, two or more holes werecored at all sites and used to construct compositesections.

Our composite sections and splice constructionmethodology follows one which has been success-fully employed during a number of previous legs ofthe ODP (e.g., Hagelberg et al., 1992; Curry, Shackle-ton, Richter, et al., 1995; Jansen, Raymo, Blum, et al.,1996; Lyle, Koizumi, Richter, et al., 1997; Gersonde,Hodell, Blum, et al., 1999, Wang, Prell, Blum, et al.,2000; Mix, Tiedemann, Blum, et al., 2003; Zachos,Kroon, Blum, et al., 2004; among others) and, mostrecently, during Expedition 303 (see “Compositesection” in the “Site U1308–U1311 methods” chap-ter). Assembly and verification of a complete com-posite stratigraphic section requires construction of acomposite depth scale. Other depth scales (discussedbelow) can be implemented using downhole logging

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data and/or combining splicing and drill pipedepths.

Once a composite depth scale has been completed, astratigraphically continuous and complete compos-ite splice can be created from representative intervalsfrom the multiple holes. Ideally, both core-recoverygaps and intervals with coring deformation are ab-sent in the spliced section. The continuity and com-pleteness of the spliced section is dependent onavoiding coeval core-recovery gaps in the multipleholes, which can be done through real time adjust-ments to the depths at which a core is collected asdiscussed below.

Meters composite depth scaleThe goal of constructing a composite depth scale isto place coeval, laterally continuous stratigraphicfeatures into a common frame of reference by depthshifting the mbsf depth scales of individual cores tomaximize correlation between holes. In the compos-ite depth scale used by ODP and IODP, referred to asthe mcd scale, the depths of the individual cores canonly be shifted by a constant amount, without per-mitting expansion or contraction of the relativedepth scale within any core. Ultimately, this pro-vides good first-order correlation between cores fromdifferent holes while also avoiding more subjective,and potentially erroneous, interpretations thatmight arise without applying this restriction first.The mcd scale, once established, provides a basisupon which higher-order depth composite scales canbe built.

In essence, the mcd scale overcomes many of the in-adequacies of the mbsf depth scale, which is basedon drill pipe measurements and is unique to eachhole. The mbsf depth scale is based on the lengththat the drill string is advanced on a core by core ba-sis and is often inaccurate because of ship heave(which is not compensated for in APC coring), tidalvariations in sea level, and other sources of error. Incontrast, the mcd scale is built by assuming that theuppermost sediment (commonly referred to as themudline) in the first core from a given hole is thesediment/water interface. This core becomes the “an-chor” in the composite depth scale and is typicallythe only one in which depths are the same on boththe mbsf and mcd scales. From this anchor, core log-ging data are correlated among holes downsection.For each core, a depth offset (a constant) that bestaligns the observed lithologic variations to theequivalent cores in adjacent holes is added to thembsf depth in sequence down the holes. Depth off-sets are often chosen to optimize correlation of spe-cific features that define splice levels in cores fromadjacent holes.


For Expedition 306, the mcd scale and the splice arebased on the stratigraphic correlation of data fromthe IODP whole-core MSCL, MST, AMST, and long-core magnetometer. For each of these track instru-ments, data were collected every 2, 2.5, 4, or 5 cm.We used magnetic susceptibility (the data are re-ferred to as MSCL if collected using the MSCL or MS-MST if collected using the MST), gamma ray attenua-tion (GRA) bulk density, natural gamma radiation(NGR), reflectance (L*, a*, and b*), and the intensityof magnetization following 20 mT AF demagnetiza-tion. All of these measurements are described in“Physical properties” and “Paleomagnetism.”

The raw stratigraphic data were imported into Splicer(version 2.2) and culled as necessary to avoid incor-porating anomalous data influenced by edge effectsat section boundaries. Splicer was used to assess thestratigraphic continuity of the recovered sedimen-tary sequences at each drill site and to construct themcd scale and splice.

Because depth intervals within cores are notsqueezed or stretched by Splicer, all correlative fea-tures cannot be aligned. Stretching or squeezing be-tween cores from different holes may reflect small-scale differences in sedimentation and/or distortioncaused by the coring and archiving processes. Thetops of APC cores are generally stretched and thebottoms compressed, although this is lithology de-pendent. In addition, sediment (especially unconsol-idated mud, ash, sand, and gravel) occasionally fallsfrom higher levels in the borehole onto the tops ofcores as they are recovered, and as a result the top 0–100 cm of many cores are not part of the stratigraph-ically contiguous section.

Correlations among cores from adjacent holes areevaluated visually and statistically by cross-correlation within a 2 m depth interval, which canbe adjusted in size when appropriate. Depth-shifteddata are denoted by mcd. A table is presented in eachsite chapter that summarizes the depth offsets foreach core. These tables are necessary for convertingmbsf to mcd scales. The mcd for any point within acore equals the mbsf plus the cumulative offset. Cor-relation at finer resolution is not possible withSplicer because depth adjustments are applied lin-early to individual cores; no adjustments, such assqueezing and stretching, are made within cores.Such fine-scale adjustment is possible postcruise(e.g., Hagelberg et al., 1995).

SplicingOnce all cores have been depth-shifted and strati-graphically aligned, a composite section is built bysplicing segments together from multiple holes toform a complete record at a site. It is composed of

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core sections from adjacent holes so that coring gapsin one hole are filled with core intervals from an ad-jacent hole. The splice does not contain coring gaps,and an effort has been made to minimize inclusionof disturbed sections. The shipboard splice is ideallysuited to guide core sampling for detailed paleocean-ographic studies. A table and a figure presented ineach site chapter summarize the intervals from eachhole used to construct the splice. Additional splicesmay be constructed postcruise as needed.

The choice of tie points (and hence of a splice) is asomewhat subjective exercise. Our method in theconstruction of a splice followed three rules. First,where possible we avoided using the top and bottom~0.5 m of cores, where disturbance resulting fromdrilling artifacts (even if not apparent in core loggingdata) was most likely. Second, we attempted to incor-porate those portions of the recovered core that weremost representative of the overall stratigraphic sec-tion of the site. Third, we tried to minimize thenumber of tie points to simplify sampling.

The length of the spliced section (on the mcd scale)at a given site is typically ~5%–15% greater than thelength of the cored section in any one hole as indi-cated by the mbsf scale. This increase is commonlyattributed to sediment expansion resulting fromelastic rebound, stretching during the coring process,gas expansion during the core recovery process, andcuration practices, in which soupy core materialcommonly occurring at the top of many cores is cu-rated as part of the core (e.g., Moran, 1997; Acton etal., 2001). In reality, much of the soupy material re-sults from sediment falling into the hole or from sed-iment being stirred at the bottom of the hole as theBHA is advanced.

Ideally, the base of the mcd scale is the bottom of thedeepest core recovered from the deepest hole. Inpractice, however, the base often occurs where corerecovery gaps align across all holes or the data qual-ity does not allow reliable correlations betweenholes. Cores below this interval cannot be directlytied into the overlying and continuous mcd. How-ever, below the base of the continuous mcd, coresfrom two or more holes can sometimes be correlatedwith each other to create a floating splice. In thiscase an mcd was assigned to the section below thesplice by adding the greatest cumulative offset to thefirst core below the splice and beginning the floatingsplice from that point in the section.

Corrected meters composite depthTo correct the mcd scale for empirically observedcore expansion, a growth factor (GF) is calculated byfitting a line to mbsf versus mcd. By dividing mcd byGF a corrected meters composite depth scale can be


evaluated which is a close approximation of the ac-tual drilling depth scale. It should be noted, how-ever, that the actual GF is not linear and varies withlithology.

Magnetic Susceptibility Core LoggerIn order to permit rapid stratigraphic correlation forreal-time drilling adjustments, the MSCL was usedfor only the second time during an IODP expedi-tion. The MSCL is a simple track system with twomagnetic susceptibility loops separated by 45 cm(see “Physical properties”). It was developed topermit rapid measurement of susceptibility onwhole-core sections as soon as possible followingrecovery. The concept was first attempted duringODP Leg 202 using a similar instrument from Ore-gon State University. During Expedition 303, thecurrent track system was used, but the system didnot function properly in dual sensor mode and soonly single-sensor data were collected (see “Physi-cal properties” in the “Site U1302–U1308 methods”chapter).

Unlike Expedition 303, during Expedition 306 wedid not experience any problems with the dual sen-sors. We were thus able to run the track in dual-sen-sor mode for all sections measured using a samplinginterval of 10 cm for each loop, which results in a 5cm overall data spacing. Five measurements weremade at each interval using SI units and the short(~1 s) measurement setting on the Bartington sus-ceptibility meters. At these settings, we could log atypical 9.5 m long core in ~30 min.

Rare data spikes occurred for reasons yet to be deter-mined, although shielding the cables to the suscepti-bility meters and keeping cables away from the loopsappeared to reduce the frequency of these spikes.These are manifested by single negative values orspikes that differ significantly from real susceptibilityvalues. They were therefore easy to detect and to re-move before the data were uploaded into the data-base. Once in the database, relative offsets betweenthe two meters are mostly removed, providing a con-sistent data set with higher resolution than could beobtained with a single susceptibility meter in thesame amount of time. During Expedition 306, wenoted that small systematic differences existed be-tween the two meters even after the offset correc-tion, but these are virtually imperceptible when thedata are loaded into Splicer using the five-pointsmoothing option.

The MSCL susceptibility data are used in Splicer forpreliminary stratigraphic correlation with the goal ofdetermining if between-core gaps in one hole corre-spond with those in a hole that is being cored. If so,drilling adjustments can be made to ensure that co-

13


eval coring gaps are avoided in subsequent cores. Ba-sically, the stratigraphic correlators are able to guidethe drilling in real time to avoid having coeval cor-ing gaps in multiple holes cored at a site, whichwould result in an incomplete stratigraphic section.This preliminary susceptibility data set is then super-ceded by the magnetic susceptibility measurementscollected on the MST, which is done after the coreshave equilibrated to room temperature and generallyat higher resolution than on the MSCL. Likewise, thepreliminary stratigraphic correlation is supercededby more careful evaluation following the collectionof a suite of physical property data and core descrip-tions.

Depths in splice tables versus Janus depths

The depth of a core interval recorded for a tie pointin a splice table is not always the same as the depthfor the same core interval returned by most databasequeries. This is because the tie point depth is basedon the liner length, measured when the cores are cutinto sections on the catwalk. The cores are analyzedon the MSCL almost immediately after this linerlength measurement. At some later time, typically 10to 36 h after being analyzed by the MST, core sec-tions are split and analyzed further (see “Core han-dling and analysis”). At this time, the sectionlengths are measured again and are archived as “cu-rated lengths.” General database queries returndepths based on the curated liner lengths. Becausethe sections may have expanded during the periodbetween the two measurements or shifted duringsplitting and handling, the curated length is almostalways longer than the initial liner length. Thus, thedepths associated with the MST data used to con-struct the splice table are not identical to the finaldepths assigned to a given interval by the database.This leads to small differences, usually between 0and 5 cm, between the mbsf and mcd recorded in asplice table and the depths reported in other placesfor the same core interval. We have chosen not tochange these depths to be compatible with Janus be-cause this would not improve their accuracy. Forconsistency, we recommend that all postcruise depthmodels use or build on mcd values provided in theJanus database.

GeochemistryThe shipboard geochemistry program for Expedition306 included characterization of (1) volatile hydro-carbons, (2) interstitial water, (3) sedimentary inor-ganic and organic carbon and total nitrogen, and(4) examination of solvent-extractable organic com-


pounds. Volatile hydrocarbon analyses were carriedout as part of the routine shipboard safety and pollu-tion prevention requirements.

Sediment gas sampling and analysisDuring Expedition 306, the compositions and con-centrations of volatile hydrocarbons in the sedi-ments were analyzed once per core using the routineheadspace procedure (Pimmel and Claypool, 2001).This procedure involved placing ~5 cm3 of sedimentsample in a 21.5 cm3 glass serum vial that was sealedwith a septum and metal crimp cap immediately af-ter core retrieval on deck. In the shipboard labora-tory, the glass vial was heated at 60°C for 30 min.Five cubic centimeters of gas was removed from theheadspace in the vial with a glass syringe for analysisby gas chromatography.

Headspace gas samples were analyzed using aHewlett-Packard 6890 Plus gas chromatograph (GC)equipped with a 2.4 m × 3.2 mm stainless steel col-umn packed with 80/100 mesh HayeSep S and aflame ionization detector (FID). This analytical sys-tem measures the concentrations of methane (C1),ethane (C2), ethene (C2=), propane (C3), and propene(C3=). The sample gas syringe was directly connectedto the GC via a 1 cm3 sample loop. Helium was usedas the carrier gas, and the GC oven temperature washeld at 90°C. Calibrations were conducted using ana-lyzed gases, and gas concentrations were measuredin parts per million by volume.

Interstitial water sampling and chemistryInterstitial waters were extracted from 5 cm longwhole-round sediment sections that were cut andcapped immediately after core retrieval on deck. Inone hole at each site, samples were taken from eachcore for the upper 60 mbsf and at intervals of everythird core thereafter to a depth of 110 mbsf. In addi-tion to whole-round samples, small plug sedimentsamples of ~10 cm3 were taken with a syringe at SiteU1313 for shore-based analyses of oxygen isotopes,deuterium, and chloride. These samples were takenat a resolution of two per core for Cores 1 and 2, oneper section for Cores 3 through 5, two for Core 6,and one per core for Cores 7, 8, 10, and 11. The smallplug samples were taken from the working half atthe time of sectioning on deck. This sampling tech-nique was used to obtain high-resolution interstitialwater samples while maintaining the integrity of thecomposite section.

In the shipboard laboratory, whole-round sedimentsamples were removed from the core liner, and theoutside surfaces of the sediment samples were care-fully scraped off with spatulas to minimize potential

14


contamination with drill fluids. Sediment sampleswere then placed into a Manheim titanium squeezerand squeezed at ambient temperature with a Carverhydraulic press (Manheim and Sayles, 1974). Inter-stitial water samples discharged from the squeezerwere passed through 0.45 µm Whatman polyether-sulfone membrane filters, collected in plastic sy-ringes, and stored in plastic sample tubes for ship-board analyses or archived in glass ampoules and/orheat-sealed acid-washed plastic tubes for shore-basedanalysis. For shipboard inductively coupled plasma–atomic emission spectroscopy (ICP-AES) analysis, 25µL of concentrated HNO3 was added to the samplesprior storage. The squeezed sediment residues weresplit in portions of approximately one-quarter andthree-quarters. The one-quarter portion was freeze-dried, ground, and used for shipboard organicgeochemical analyses (see below). The rest of theportion was stored for shore-based analysis.

Shipboard analyses of whole-round interstitial watersamples followed the procedures outlined by Gieskeset al. (1991) and Murray et al. (2000) with modifica-tions as summarized below. Salinity was measuredwith an Index Instruments digital refractometer. Al-kalinity and pH were measured by Gran titrationwith a Brinkman pH electrode and a Metrohm au-totitrator. NH4

+ concentrations were analyzed byspectrophotometric methods with a Milton Royspectrophotometer. For the analyses of Mg2+, Ca2+, K+,Na+, Mn2+, Fe2+, B, Sr2+, Ba2+, Li+, and H4SiO4 concen-trations, a Jobin Yvon JY2000 ICP-AES was used.Concentrations of SO4

2– were determined with a Di-onex ion chromatograph. Cl– was measured by silvernitrate titration method using a Metrohm titrator.

Analytical precision for each of the techniques wasmonitored through multiple analyses of Interna-tional Association of Physical Sciences Organization(IAPSO) standard seawater solution or other standardsolutions and is reported in Table T3.

For calibrations of major elements measured by ICP-AES, IAPSO solutions of Mg2+, Ca2+, K+, and Na+ di-luted with 18 MS deionized water to 0%, 20%, 40%,60%, 80%, 100%, 120%, 140%, and 160% were usedat the beginning of each batch (i.e., site) run.

Minor elemental analysis by ICP-AES was modifiedfrom Murray et al. (2000) as outlined in ShipboardScientific Party (2003a). Specifically, a “master stan-dard” was prepared by blending certified standardsolutions of Mn2+, Fe2+, B, Sr2+, Ba2+, and Li+ and a sili-con reference solution (sodium silicate) in an acidi-fied (1.25% HNO3, by volume) sodium chloride ma-trix (17.5 g NaCl/L) diluted with 18 MS deionizedwater. This solution was diluted to 0%, 3%, 5%, 10%,30%, 50%, and 100% with a NaCl/HNO3 matrix (35


g NaCl + 2.5% HNO3 per 1 L) to generate “workingstandard” solutions. Calibrations were made for eachof the chemical constituents measured on ICP-AESusing the working standard solutions diluted with amatrix solution (2.5% HNO3 + 10 ppm yttrium as aninternal standard) prior to each batch (i.e., site) run.Samples were diluted 1:50 for major and 1:10 for mi-nor elements prior to ICP-AES analyses. Chemicaldata for interstitial water are reported in molar con-centration units.

Sedimentary inorganic and organic carbon and nitrogen concentrations

Inorganic carbon concentrations were determinedusing a Coulometrics 5011 carbon dioxide coulome-ter equipped with a carbonate analyzer. Two carbon-ate analyses were performed for each core. Samplesof ~10 mg of freeze-dried, ground sediment were re-acted with 2N HCl. The liberated CO2 was backti-trated to a colorimetric end point. Calcium carbon-ate (CaCO3) content, as weight percent, wascalculated from the inorganic carbon (IC) contentwith the assumption that all inorganic carbon ispresent as calcium carbonate:

CaCO3 (wt%) = IC (wt%) × 8.33. (1)

No corrections were made for other carbonate min-erals. The coulometer was calibrated with pureCaCO3 powder during the expedition, and the ana-lytical precision (expressed as 1F standard deviationsof means of multiple determinations of a standard)for IC was ±0.45% (for Site U1312).

Total carbon (TC), total nitrogen (TN), and total hy-drogen were determined using a Carlo Erba 1500CHNS analyzer on the same samples used for inor-ganic carbon concentrations. Aliquots of ~10 mg offreeze-dried, ground sediment and ~10 mg V2O5 asco-oxidant were combusted at 1000°C in a stream ofoxygen. Nitrogen oxides were reduced to N2, and themixture of N2, CO2, and H2O gases was separated byGC and detection performed by a thermal conduc-tivity detector. All measurements were calibrated bycomparison to pure sulfanilamide as standard. Ana-lytical precision for TC and TN was 1.99% and1.07%, respectively (1F standard deviation of meansof multiple determinations of sulfanilamide for SitesU1312, U1313, and U1314). Despite low 1F standarddeviation for TN, we noticed in sediments from HoleU1314A and partly Hole U1313A that systematic off-sets in TN of sample sets run within different batchesoccurred and initially generated obvious staircase-like downhole profiles. In case of such observations,samples were submitted for rerun. However, shore-based elemental reanalysis of the shipboard samples

15


will be additionally performed and reported else-where.

Contents of total organic carbon (TOC), as weightpercent, were calculated as the difference betweenTC and IC:

TOC (wt%) = TC (wt%) – IC (wt%). (2)

As most of the samples had very high CaCO3 con-tents and very low TOC values (see respective sitechapters), the TOC data determined during Expedi-tion 306 should be considered as preliminary, keep-ing in mind its methodological (i.e., calculatedrather then measured) limitation. Indeed, postcruiseanalysis of shipboard samples from all three sites bymeans of direct TOC measurement using a LECO CS-125 analyzer (J. Hefter, unpubl. data, 2006) showedno correlation (Fig. F10), especially for samples richin carbonate (>90 wt%, e.g., most of the samplesfrom Hole U1312A).

Solvent-extractable organic compoundsA limited number of sediment samples were ana-lyzed onboard for solvent-extractable organic com-pounds to determine initial organic matter charac-teristics for subsequent shore-based analyses (seeindividual site chapters for numbers and depths). Forthe shipboard organic geochemistry analyses, freeze-dried splits of one-quarter of whole-round sedimentsqueeze cakes, used for interstitial water (samplingcode IWSG) sampling, were used. To perform the ex-traction, 10–25 g of sediment was ultrasonically ex-tracted in two 40 mL glass tubes using 20–40 mLCH2Cl2 for 15 min. Sediments and solvents were sep-arated in a centrifuge at 2500 rpm for 5 min, and thesolvent phase was decanted and collected. The ex-traction step was repeated by adding 10–20 mL offresh CH2Cl2 to the sediment remnants. The com-bined total extracts were reduced to near dryness bya gentle stream of N2. Depending on the amount ofTOC and the color of the extracts, total extracts wereeither directly injected into the GC-mass spectrome-ter (MS) or further separated by column chromatog-raphy. Silica gel (100–200 mesh, dried at 120°C over-night) was placed in a Pasteur pipette plugged withcotton wool and preconditioned by successive elu-tion with 4 mL of CH2Cl2 and 4 mL of hexane. Totalextracts, redissolved in a small amount (100–200 µL)of hexane, were placed on top and separated intotwo subfractions by elution with 4 mL of hexane and4 mL of CH2Cl2, respectively. Note that the above an-alytical procedure will not allow the detection of cer-tain types of compound classes (e.g., fatty acids, al-cohols, sterols, etc.) because of the lack ofderivatization steps.


The GC-MS system used for compound identifica-tion consists of an HP 6890 GC equipped with an HP7683 automatic liquid sampler and is interfaced via aheated (280°C) transfer line to an HP 5973 mass-selective detector (MSD). Total extracts or subfrac-tions dissolved in a final volume of 100 µL hexanewere injected into an electronic pneumatic-controlled split-splitless injector (operated in split-less mode at 300°C; injection volume = 1 µL). Com-pounds were separated on an HP-5MS capillary col-umn (30 m × 0.25 mm; film thickness = 0.25 µm),using He in constant flow mode (1 mL/min) as car-rier gas. The GC temperature program was as follows:40°C (hold 2 min), heat to 130°C (rate = 20°C/min),heat to 320°C (rate = 4°C/min), and hold 20 min at320°C. The source temperature of the MSD was set to230°C and the quadrupole mass analyzer to 150°C.Mass spectra were recorded in full-scan mode fromm/z 50 to 600 at a scan rate of 2.7 spectra/s. Com-pounds were identified by their mass spectral charac-teristics and GC retention times and by comparisonwith published mass spectral data or mass spectraldatabases (NIST, Wiley). Unfortunately, the MS couldonly be used for Site U1312. Later, the high-voltagesupply of the mass analyzer failed and was found notto be repairable for the remaining of the expeditiondue to the lack of spare electronic parts. As an alter-native, we had to use the FID installed on the HP6890 GC. Identification of n-alkanes at the followingsites, however, could be established relatively easilyby comparison to retention times obtained from astandard mixture containing all homologs from n-C10 to n-C36. The identification of C37 and C38 alk-enones is based on their well-known retention times(e.g., >C38 n-alkane under the GC conditions used),their specific elution order, and their overall charac-teristic distribution pattern. Identification of com-pounds designated as contaminants (mainly plastic-derived, e.g., homologs of phthalate esters) for GC-FID runs is based on previous GC-MS identificationsof those compounds in blank and analytical proce-dure tests and intercomparison of retention times af-ter reruns of the appropriate fractions under GC-FIDconditions.

Physical propertiesPhysical properties were measured on core materialrecovered during Expedition 306 to

1. Allow real-time stratigraphic correlation andfeedback to the drillers;

2. Provide further data for the hole-to-holecore correlation of any given site and forthe construction of composite stratigraphicsequences;

16


3. Detect changes in sediment properties thatcould be related to lithologic changes,diagenetic features, or consolidation history;

4. Provide the dry density records needed forcomputing mass accumulation rates;

5. Identify natural and/or coring-induceddiscontinuities; and

6. Provide data to aid interpretation of seismicreflection and downhole geophysical logs.

Magnetic susceptibility was first measured with theGeotek MSCL on whole-round core sectionsimmediately after recovery. These measurementsaided real-time stratigraphic correlation withoutbeing limited by the time constraints of MSTmeasurements. After the cores reached roomtemperature, magnetic susceptibility, GRA bulkdensity, and NGR were measured on the whole-coreMST. Noncontact resistivity was not measured.

Split-core measurements on the working half of thecore included VP with the IODP P-wave sensor num-ber 3 (PWS3–measuring perpendicular to the coreaxis) and moisture and density. A comprehensive de-scription of most of the methodologies and calcula-tions used in the JOIDES Resolution physical proper-ties laboratory can be found in Blum (1997).

Magnetic susceptibility MSCL sampling strategy

Rapid stratigraphic correlation of cores fromadjacent holes and real-time feedback to drillers forrecovering complete stratigraphic sections at all siteswas important. An automated dedicated MSCL forrapid measurement of magnetic susceptibility wasused to provide a nondestructive proxy of sedimentvariability to the stratigraphic correlators.Measurements were made as soon as whole-coresections became available. The MSCL systememploys a Geotek track system with dual BartingtonMS2C meters and two 80 mm inside diameter coilsseparated by 45 cm. Because of the proximity of thecoils to each other, different frequencies were used toreduce interference: 0.621 kHz for the first and 0.513kHz for the second. Distinct correction factors (1.099and 0.908, respectively) must be used to synchronizedata acquired from the two loops. Measurementswere taken every 10 cm. The use of two loopsallowed simultaneous interlaced measurements,decreasing the sampling interval to 5 cm. This wasfast enough to keep up with core recovery undermost circumstances and is significantly faster thanthe MST logging time. The Geotek uses a core pushersystem that measures sections continuously,minimizing edge effects at section breaks. The sus-ceptibility data collected with the MSCL is not ap-propriate for other uses because cores were measured


prior to warming to room temperature and tempera-ture drift corrections were not made.

The MST susceptibility meter (a Bartington MS2Cmeter with an 80 mm coil diameter driven at 0.565kHz frequency) was set on SI units, and the outputvalues were stored in the Janus database. The widthat half-height of the response function of thesusceptibility coil is ~4 cm (Blum, 1997), and thesensing region corresponds to a cored volume of160. To convert the stored values to SI units ofvolume susceptibility, values should be multiplied by10–5 and by a correction factor to take into accountthe volume of material within the response functionof the susceptibility coils. For a standard IODP core,this factor is ~6.8 × 10–5 (Thomas et al., 2001), basedon laboratory/ship comparisons for Leg 162sediments. More recent estimates based on Leg 202sediments suggest a factor of ~6 × 10–5 SI units.

Multisensor track sampling strategyMagnetic susceptibility, GRA bulk density, and NGRwere measured nondestructively on all whole-roundcore sections with the MST. The noncontactresistivity and compressional wave velocity loggerswere not working, and these parameters were notmeasured. To optimize MST performance, samplingintervals and measurement residence times were thesame for all sensors for any one core. Samplingintervals were therefore set at 2.5 or 5 cm, dependingon time constraints. These sampling intervals arecommon denominators of the distances between thesensors installed on the MST (30–50 cm) and allowtruly simultaneous measurements and thereforeoptimal use of total measurement times.

We endeavored to optimize the trade-off betweencore logging times and depth resolution. Longeranalysis times were selected if required to improvemeasurement precision. These times varied from 3 to5 s, with most cores measured at 5 s per sample.

The total time availability for MST logging at a sitewas predicted based on the operational time estimatefor the site, subsequent transit time, and any othertime available before core was on deck at the subse-quent site. Sampling parameters were then opti-mized to use the total available time (e.g., 2.5 cmand 5 s [~2 h/core]; 5 cm and 5 s [~1.2 h/core]; 5 cmand 3 s [fast logging, ~0.9 h/core]).

Magnetic susceptibilityMagnetic susceptibility is a measure of the degree towhich a material can be magnetized by an externalmagnetic field. It provides information on themagnetic composition of the sediments that oftencan be related to mineralogical composition (e.g.,

17


terrigenous versus biogenic materials) and/ordiagenetic overprinting. Magnetite and a few otheriron oxides with ferromagnetic characteristics have aspecific magnetic susceptibility several orders ofmagnitude higher than clay, which hasparamagnetic properties. Carbonate, silica, water,and plastics (core liner) have small and negativevalues of magnetic susceptibility. Sediments rich inbiogenic carbonate and opal therefore have generallylow magnetic susceptibility, even negative values, ifpractically no clay or magnetite is present. In suchcases, measured values approach the detection limitof magnetic susceptibility meters.

Magnetic susceptibility was measured with theBartington Instruments MS2C system on both theMST and the MSCL. The output of the magnetic sus-ceptibility sensors can be set to centimeter-gram-second (cgs) units or SI units.The IODP standard isthe SI setting. However, to actually obtain thedimensionless SI volume-specific magneticsusceptibility values, the instrument units stored inthe IODP database must be multiplied by acorrection factor to compensate for instrumentscaling and the geometric ratio between core andloop dimensions, as described above.

A common operational problem with the Bartingtonmeter is that 1 s measurements are rapid but notprecise enough for biogenic-rich sediments and the10 s measurements are much more precise but take aprohibitively long time to measure at the desiredsampling interval of 2.5 to 5 cm. The MST programwas therefore equipped with the option to averageany number of 1 s measurements, and we usuallyaveraged five such measurements.

Gamma ray attenuation bulk densityBulk density reflects the combined effect ofvariations in porosity, grain density (dominantmineralogy), and coring disturbance. Porosity ismainly controlled by lithology, texture (e.g., clay,biogenic silica, and carbonate content and grain sizeand sorting), compaction, and cementation.

The GRA densitometer comprises a 10 mCi 137Cscapsule as the gamma ray source with the principalenergy peak at 0.662 MeV and a scintillationdetector. The narrow collimated peak is attenuated asit passes through the center of the core. Incidentphotons are scattered by the electrons of thesediment material by Compton scattering. Theattenuation of the incident intensity (I0) is directlyrelated to the electron density in the sediment core ofdiameter (D), which can be related to bulk densitygiven the average attenuation coefficient (inmicrometers) of the sediment (Harms and Choquette,


1965). Because the attenuation coefficient is similarfor most common minerals and aluminum, bulkdensity is obtained through direct calibration of thedensitometer using aluminum rods of differentdiameters mounted in a core liner that is filled withdistilled water. The GRA densitometer has a spatialresolution of <1 cm.

Natural gamma radiationTerrigenous sediment is often characterized by NGRfrom K, Th, and U, which are present mostly in claysbut can also originate from heavy minerals or lithicgrains. Uranium often dominates the NGR incarbonate-rich sediments with little terrigenousinput. Uranium concentration is largely controlledby organic matter flux to the seafloor and theexisting redox conditions there. It is also mobile andcan migrate to certain layers and diagenetichorizons.

The NGR system consists of four shieldedscintillation counters with 3 inch × 3 inch dopedsodium iodide crystals, arranged at 90° from eachother in a plane orthogonal to the core track. TheNGR response curve is ~17 cm (full-width half-maximum), an interval that could be considered areasonable sampling interval. Measurementprecision is a direct function (inverse square root) ofthe total counts (N) accumulated for onemeasurement, according to Poisson’s law of randomcounting error. N is the product of the intrinsicactivity of the material measured and the totalmeasurement time. Therefore, one seeks tomaximize the measurement time to improve dataquality. Unfortunately, time constraints on corelogging during the cruise do not permit longcounting times. Furthermore, NGR is measured every2.5 or 5 cm (same sampling interval as other MSTmeasurements for optimal MST efficiency) and,therefore, only for a relatively short time (typically 5s). It may be necessary, particularly in low-activitymaterial, to integrate (or smooth) several adjacentmeasurements to reduce the counting error to anacceptable level. Five-point smoothing is areasonable data reduction in view of the relativelywide response curve of the sensors. (See Blum, 1997,for more detailed discussions).

P-wave velocityP-wave velocity in marine sediments varies with thelithology, porosity or bulk density, state of stresssuch as lithostatic pressure, fabric or degree offracturing, degree of consolidation and lithification,occurrence and abundance of free gas and gashydrate, and other properties. P-wave velocity was

18


measured with two systems during Expedition 306,with the MST-mounted P-wave logger on whole-round cores (Schultheiss and McPhail, 1989) andwith the PWS3 on every section of the split cores. AllIODP P-wave piezoelectric transducers transmit a500 kHz compressional wave pulse through the coreat a repetition rate of 1 kHz.

Traveltime is determined by the software, whichautomatically picks the arrival of the first wavelet toa precision of 50 ns. It is difficult for an automatedroutine to pick the first arrival of a potentially weaksignal with significant background noise. The searchmethod applied skips the first positive amplitudeand finds the second positive amplitude using adetection threshold limit, typically set to 30% of themaximum amplitude of the signal. Then it finds thepreceding zero crossing and subtracts one period todetermine the first arrival. To avoid extremely weaksignals, minimum signal strength can be set(typically to 0.02 V) and weaker signals are ignored.To avoid cross-talk signals at the beginning of therecord from the receiver, a delay (typically set to 0.01ms) can be set to force the amplitude search to beginin the quiet interval preceding the first arrival. Inaddition, a trigger (typically 4 V) is selected toinitiate the arrival search process.The number ofwaveforms to be stacked (typically five) can also beset. Linear voltage differential transducers determinelength of the travel path.

The P-wave velocity systems require two types of cal-ibration, one for the displacement of the transducersand one for the time offset. For the displacement cal-ibration, five acrylic standards of different thicknessare measured and the linear voltage-distance rela-tionship determined using least-squares analyses. Forthe time offset calibration, room-temperature waterin a plastic bag is measured multiple times with dif-ferent transducer displacements. The inverse of theregression slope is equal to the velocity of sound inwater, and the intercept represents the delay in thetransducers.

Moisture content and densitySamples of 10 cm3 were taken from the working halfsections with a piston minicorer and transferred intopreviously calibrated 10 mL glass vials. Usually onesample from the top of the first section and the baseof the sixth section were taken. Sampling locationwas coordinated for P-wave velocity as well as forsubsequent extraction of specimens for carbonate.To minimize the destruction of the availablesediment on the specific sampling zones, another 2cm3 sample was collected as close as possible to thephysical properties sample for carbonate analysis.


Wet and dry weights were determined with twinScientech 202 electronic balances, which allow forcompensation of the ship’s motion effect on thebalance and give a precision better than 1%.

The samples were dried in a convection oven at atemperature of 105° ± 5°C for a period of 24 h. Dryvolume was measured in a He-displacement five-chambered pycnometer with an uncertainty of 0.02cm3. This equipment allows the simultaneousanalysis of four different samples and a calibrationsphere and took ~15–20 min. Three measurementswere averaged per sample. The calibration spherewas cycled from cell to cell of the pycnometer duringeach batch, so that all cells could be checked foraccuracy at least once every five runs.

Archive multisensor track sampling strategyTwo instruments were mounted on the AMST, theMinolta spectrophotometer measuring diffuse colorreflectance and a point magnetic susceptibilitymeter, which was not used during this cruise. Colorreflectance was measured at 2.0 cm throughoutExpedition 306 cores (for color reflectance see“Lithostratigraphy”).

Downhole measurementsDownhole logging provides continuous in situ geo-physical measurements within a borehole. Thesemeasurements are used to assess the physical, chemi-cal, and structural characteristics of formations pene-trated by drilling and thus provide a means of recon-structing the stratigraphy, lithology, and mineralogyof a sequence. Well logging is typically undertakenin the deepest hole drilled at any one site. Wherecore recovery is poor or disturbed, downhole loggingdata are often the most reliable source of informa-tion. Where core recovery is good, core data can becorrelated with logging data to refine stratigraphyand unit characterization. Downhole logging opera-tions begin after the hole has been cored and flushedwith a viscous drilling fluid. The drilling assembly isthen pulled up to ~70 mbsf, and the logging tools arepassed through the drill pipe into the open hole. Thelogging tools are joined together into tool strings sothat compatible tools are run together. Each toolstring is lowered separately to the base of the hole,and then measurement takes place as the tool stringis raised at a constant rate between 275 and 500 m/h(see “Downhole measurements” in the individualsite chapters). A wireline heave compensator is usedto minimize the effect of the ship’s heave on the toolstring position in the borehole (Goldberg, 1990).Further information on the procedures and wireline

19


tools used during Expedition 306 can be found atiodp.ldeo.columbia.edu/TOOLS_LABS/index.htmland www.ldeo.columbia.edu/BRG/ODP/LOGGING/index.html.

Logging tools and tool stringsDuring Expedition 306, the following logging toolstrings were deployed (Fig. F11; Table T4):

1. The triple combination tool string, which consistsof the Hostile Environment Gamma Ray Sonde(HNGS), the Hostile Environment Litho-DensitySonde (HLDS), the Digital Dual Induction Toolmodel E (DIT-E), and two Lamont-Doherty EarthObservatory–Borehole Research Group (LDEO-BRG) tools, the Multi-Sensor Spectral Gamma RayTool (MGT), and the Temperature/Acceleration/Pressure (TAP) tool.

2. The Formation MicroScanner (FMS)-sonic toolstring, which consists of the Scintillation GammaRay Tool (SGT), the Dipole Sonic Imager (DSI), theGeneral Purpose Inclinometer Tool (GPIT), andthe FMS.

Principles and uses of the logging toolsThe properties measured by each tool, sampling in-tervals, and vertical resolutions are summarized inTable T4. Explanations of tool name acronyms andtheir measurement units are summarized in TableT5. More detailed descriptions of individual loggingtools and their geological applications can be foundin Ellis (1987), Goldberg (1997), Rider (1996),Schlumberger (1989, 1994), Serra (1984, 1986, 1989),and the LDEO-BRG Wireline Logging Services Guide(1994).

Natural radioactivityThree wireline spectral gamma ray tools were usedduring Expedition 306 to measure and classify natu-ral radioactivity in the formation: the HNGS, theSGT, and the LDEO-BRG MGT. The HNGS measuresthe natural gamma radiation from isotopes of K, Th,and U and uses a five-window spectroscopic analysisto determine concentrations of radioactive 40K (inweight percent), 232Th (in parts per million), and 238U(in parts per million). The HNGS uses two bismuthgermanate scintillation detectors for gamma ray de-tection with full spectral processing. The spectralanalysis filters out gamma ray energies below 500keV, eliminating sensitivity to bentonite or potas-sium chloride (KCl) in the drilling mud and improv-ing measurement accuracy. The HNGS also providesa measure of the total standard gamma ray emissionand uranium-free or computed gamma ray emissionthat are measured in gAPI. The HNGS response is in-


fluenced by the borehole diameter and the weightand concentration of bentonite or KCl present in thedrilling mud. KCl may be added to the drilling mudto prevent freshwater clays from swelling and form-ing obstructions. All of these effects are correctedduring processing of HNGS data at LDEO-BRG.

The SGT uses a sodium iodide scintillation detectorto measure the total natural gamma ray emission,combining the spectral contributions of 40K, 238U,and 232Th concentrations in the formation. The SGTis not a spectral tool but provides high-resolution to-tal gamma ray data for depth correlation betweenlogging strings. It is included in the FMS-sonic toolstring to provide a reference log to correlate anddepth between different logging runs. In the FMS-sonic tool string, the SGT is placed between the twotools, providing correlation data to a deeper level inthe hole.

The MGT was developed by LDEO-BRG to improvethe vertical resolution of natural gamma ray logs byusing an array of four short detector modules with60 cm spacing. Each module comprises a small 2inch × 4 inch NaI detector, a programmable 256-channel amplitude analyzer, and a 241Am calibrationsource. The spectral data are subsequently recalcu-lated to determine the concentration of K, Th, and Uradioisotopes or their equivalents. The spectral datafrom individual modules are sampled four times persecond and stacked in real time based on the loggingspeed. This approach increases vertical resolution bya factor of two to three over conventional toolswhile preserving comparable counting efficiency andspectral resolution. The radius of investigation de-pends on several factors: hole size, mud density, for-mation bulk density (denser formations display aslightly lower radioactivity), and the energy of thegamma rays (a higher-energy gamma ray can reachthe detector from deeper in the formation). TheMGT also includes an accelerometer channel to im-prove data stacking by the precise measurement oflogging speed. Postcruise corrections for boreholesize and tool sticking, based respectively on the cali-per and acceleration data, are possible.

DensityFormation density was determined with the HLDS.The tool contains a radioactive cesium (137Cs) gammaray source (622 keV) and far and near gamma ray de-tectors mounted on a shielded skid that is pressedagainst the borehole wall by a hydraulically acti-vated eccentralizing arm. Gamma rays emitted bythe source experience both Compton scattering andphotoelectric absorption. Compton scattering in-volves the ricochet of gamma rays off electrons inthe formation via elastic collision, transferring en-

20

http://iodp.ldeo.columbia.edu/TOOLS_LABS/index.html

www.ldeo.columbia.edu/BRG/ODP/LOGGING/index.html

www.ldeo.columbia.edu/BRG/ODP/LOGGING/index.html


ergy to the electron in the process. The number ofscattered gamma rays that reach the detectors is di-rectly related to the number of electrons in the for-mation, which is related to bulk density. Porositymay also be derived from this bulk density if the ma-trix density is known.

The HLDS also measures the photoelectric effect fac-tor (PEF) caused by absorption of low-energy gammaradiation. Photoelectric absorption occurs whengamma radiation reaches <150 keV after being re-peatedly scattered by electrons in the formation. Asthe PEF depends on the atomic number of the ele-ments in the formation, it is essentially independentof porosity. Thus, the PEF varies according to thechemical composition of the formation. PEF valuescan be used in combination with HNGS curves toidentify different types of clay minerals. Couplingbetween the tool and borehole wall is essential forgood HLDS logs. Poor contact results in underestima-tion of density values. Both density correction andcaliper measurement of the hole are used to checkthe contact quality.

PorosityFormation porosity was measured with the APS. Thesonde incorporates a minitron neutron generatorthat produces fast neutrons (14.4 MeV) and five neu-tron detectors (four epithermal and one thermal) po-sitioned at differing intervals from the minitron. Themeasurement principle involves counting neutronsthat arrive at the detectors after being slowed byneutron absorbers surrounding the tool. The highestenergy loss occurs when neutrons collide with hy-drogen nuclei, which have practically the same massas the neutron (the neutrons simply bounce offheavier elements without losing much energy). Ifhydrogen concentration is low, as in low-porosityformations, neutrons can travel farther before beingcaptured, and the count rates increase at the detec-tor. The opposite effect occurs when the water con-tent is high. However, because hydrogen bound inminerals such as clays or in hydrocarbons also con-tributes to the measurement, the raw porosity valueis often an overestimate. Upon reaching thermal en-ergies (0.025 eV), the neutrons are captured by thenuclei of Cl, B, Cd, and other rare earth and trace el-ements with large capture cross sections, resulting ina gamma ray emission. This neutron capture crosssection (3f) is also measured by the tool.

Electrical resistivityThe DIT-E was used to measure electrical resistivity.The DIT-E provides three measures of electrical resis-tivity, each with a different depth of penetration.The two induction devices (deep and medium


depths of penetration) transmit high-frequency al-ternating currents through transmitter coils, creatingmagnetic fields that induce secondary currents inthe formation. These currents produce a new induc-tive signal, proportional to the conductivity of theformation, which is measured by the receiving coils.The measured conductivities are then converted toresistivity (measured in ohm-meters). For the shal-low-penetration resistivity, the current necessary tomaintain a constant voltage drop across a fixed in-terval is measured; it is a direct measurement of resis-tivity. Sand grains and hydrocarbons are electrical in-sulators, whereas ionic solutions and clays are moreconductive. Electrical resistivity can therefore beused to evaluate porosity (by Archie’s law) if fluid sa-linity is known.

Temperature, acceleration, and pressureDownhole temperature, acceleration, and pressurewere measured with the LDEO-BRG high-resolutionTAP tool run in memory mode. The tool uses fast-and slow-response thermistors to detect boreholefluid temperature at two different rates. The fast-response thermistor detects small, abrupt changes intemperature, whereas the slow-response thermistormore accurately estimates temperature gradients andthermal regimes. A pressure transducer is used to ac-tivate the tool at a specified depth, typically 200 mabove seafloor. A three-axis accelerometer measurestool movement downhole, providing data for ana-lyzing the effects of heave on a deployed tool string.The acceleration log can aid in deconvolving heaveeffects postcruise. The elapsed time between the endof drilling and the logging operation is generally notsufficient to allow the borehole to reach thermalequilibrium following circulation of the drillingfluid. Nevertheless, it is possible to identify abrupttemperature changes that may represent localizedfluid flow into the borehole, indicative of fluid path-ways and fracturing and/or breaks in the tempera-ture gradient that may correspond to contrasts inpermeability at lithologic boundaries.

Acoustic velocityThe DSI measures the transit times between sonictransmitters and an array of eight receivers. It aver-ages replicate measurements, thus providing a directmeasurement of sound velocity through sedimentsthat is relatively free from the effects of formationdamage and borehole enlargement (Schlumberger,1989). The tool contains the monopole transmittersfound on most sonic tools but also has two cross-dipole transmitters, providing shear wave velocitymeasurement in addition to the compressional wavevelocity, even in the slow formations typically en-countered during IODP expeditions.

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Formation MicroScannerThe FMS provides high-resolution electrical resistiv-ity–derived images of the borehole (~30% of a 25 cmdiameter borehole on each pass). The vertical resolu-tion of FMS images is ~5 mm, allowing features suchas clasts, thin beds, and bioturbation to be imaged.The resistivity measurements are converted to coloror grayscale images for display. The tool uses four or-thogonal imaging pads, each containing 16 buttonelectrodes that are pressed against the borehole wallduring the recording. A focused current is emittedfrom the button electrodes into the formation, witha return electrode near the top of the tool. The inten-sity of current passing through the button electrodesis measured and converted to an image. With theFMS tool, features such as bedding, fracturing, slumpfolding, and bioturbation can be resolved, and spa-tially oriented images allow fabric analysis and bedorientations to be measured (Luthi, 1990; Lovell etal., 1998; Salimullah and Stow, 1992). The maximumextension of the caliper arms is 15 inches, so in holesor parts of holes where the diameter is larger the padcontact will be inconsistent and the FMS images mayappear out of focus and too conductive. Irregularborehole walls will also adversely affect the imagequality if it leads to poor pad-wall contact.

In site chapters in this volume, local contrasts inFMS images were improved by applying dynamicand static normalizations to the FMS data. A lineargain is applied, which keeps a constant mean andstandard deviation within a sliding window of ~1 mor the entire logged interval, respectively. FMS im-ages are oriented to magnetic north using the GPIT.This method allows the dip and strike of geologicalfeatures intersecting the hole to be measured fromprocessed FMS images.

Accelerometry and magnetic field measurement

Three-component acceleration and magnetic fieldmeasurements were made with the GPIT. The pri-mary purpose of this tool, which incorporates athree-component accelerometer and a three-compo-nent magnetometer, is to determine the accelerationand orientation of the FMS-sonic tool string duringlogging. This provides a means of correcting the FMSimages for irregular tool motion, allowing the truedip and direction (azimuth) of structures to be deter-mined.

Wireline logging data qualityLogging data quality may be seriously degraded bychanges in the hole diameter and in sections wherethe borehole diameter greatly decreases or is washed


out. Deep-investigation measurements such as resis-tivity and sonic velocity are least sensitive to bore-hole conditions. Nuclear measurements (density andneutron porosity) are more sensitive because of theirshallower depth of investigation and the effect ofdrilling fluid volume on neutron and gamma ray at-tenuation. Corrections can be applied to the originaldata to reduce these effects. HNGS and SGT data pro-vide a depth correlation between logging runs. Logsfrom different tool strings may, however, still havedepth mismatches caused by either cable stretch orship heave during recording.

Logging depth scalesThe depth of the wireline-logged measurement is de-termined from the length of the logging cable paidout at the winch on the ship. The seafloor is identi-fied on the natural gamma log by the abrupt reduc-tion in gamma ray count at the water/sedimentboundary (mudline). Discrepancies between thedrillers depth and the wireline logging depth occurbecause of incomplete heave compensation, tidalchanges, and cable stretch (~1 m/km) in the case oflogging depth. The small differences between drillpipe depth and logging depth, and the even moresignificant discrepancy between IODP curationdepth and logging depth, should be taken into ac-count when using the logs for correlation betweencore and logging data. Core measurements, such assusceptibility and density, can be correlated with theequivalent downhole logs using the Sagan program,which allows linear shifting of the core depths ontothe logging depth scale.

Logging data flow and processingAfter logging was completed in each hole, data weretransferred to the shipboard downhole measure-ments laboratory for preliminary processing and in-terpretation. FMS image data were interpreted usingSchlumberger’s Geoframe (version 4.0.4.1) softwarepackage. Logging data were also transmitted onshorefor processing soon after each hole was logged. On-shore data processing consisted of (1) depth-shiftingall logs relative to a common datum (i.e., in mbsf),(2) corrections specific to individual tools, and(3) quality control and rejection of unrealistic orspurious values. Once processed onshore, the datawere transmitted back to the ship, providing finalprocessed logging results during the expedition. Pro-cessed data were then replotted onboard (see “Down-hole measurements” section in each site chapter).Postcruise-processed data in ASCII format are avail-able directly from the IODP–USIO, Science Services,LDEO Internet World Wide Web site at iodp.ldeo.co-lumbia.edu/DATA/IODP/index.html.

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ReferencesActon, G.D., Borton, C.J., and the Leg 178 Shipboard Sci-

entific Party, 2001. Palmer Deep composite depth scales for Leg 178 Sites 1098 and 1099. In Barker, P.F., Camer-lenghi, A., Acton, G.D., and Ramsay, A.T.S. (Eds.), Proc. ODP, Sci. Results, 178, 1–35 [Online]. Available from World Wide Web http://www-odp.tamu.edu/publica-tions/178_SR/VOLUME/CHAPTERS/SR178_05.PDF.

Aguirre, E., and Pasini, G., 1985. The Pliocene–Pleistocene boundary. Episodes, 8:11–120.

Akiba, F., and Yanagisawa, Y., 1986. Taxonomy, morphol-ogy and phylogeny of the Neogene diatom zonal marker species in the middle-to-high latitudes of the North Pacific. In Kagami, H., Karig, D.E., Coulbourn, W.T., et al., Init. Repts. DSDP, 87: Washington (U.S. Govt. Printing Office), 483–554.

Altenbach, A.V., Lutze, G.F., Schiebel, R., and Schoenfeld, J., 2003. Impact of interrelated and independent ecolog-ical controls on benthic foraminifera: an example from the Gulf of Guinea. Paleogeogr., Paleoclimatol., Paleo-ecol.,197:213–238. doi:10.1016/S0031-0182(03)00463-2

Backman, J., and Raffi, I., 1997. Calibration of Miocene nannofossil events to orbitally tuned cyclostratigra-phies from Ceara Rise. In Shackleton, N.J., Curry, W.B., Richter, C., and Bralower, T.J. (Eds.), Proc. ODP, Sci. Results, 154: College Station, TX (Ocean Drilling Pro-gram), 83–99. [PDF]

Baldauf, J.G., 1985. Cenozoic diatom biostratigraphy and paleoceanography of the Rockall Plateau region, North Atlantic, Deep Sea Drilling Project Leg 81. In Roberts, D.G., Schnitker, D., et al., Init. Repts. DSDP, 81: Washing-ton (U.S. Govt. Printing Office), 439–478.

Baldauf, J.G., 1987. Diatom biostratigraphy of the middle- and high-latitude North Atlantic Ocean, Deep Sea Drill-ing Project Leg 94. In Ruddiman, W.F., Kidd, R.B., Tho-mas, E., et al., Init. Repts. DSDP, 94 (Pt. 2): Washington (U.S. Govt. Printing Office), 729–762.

Balsam, W.L., and Damuth, J.E., 2000. Further investiga-tions of shipboard vs. shore-based spectral data: impli-cations for interpreting Leg 164 sediment composition. In Paull, C.K., Matsumoto, R., Wallace, P., and Dillon, W.P. (Eds.), Proc. ODP, Sci. Results, 164: College Station, TX (Ocean Drilling Program), 313–324. [HTML]

Balsam, W.L., Deaton, B.C., and Damuth, J.E., 1998. The effects of water content on diffuse reflectance spectro-photometry studies of deep-sea sediment cores. Mar. Geol., 149:177–189. doi:10.1016/S0025-3227(98)00033-4

Balsam, W.L., Damuth, J.E., and Schneider, R.R., 1997. Comparison of shipboard vs. shore-based spectral data from Amazon-Fan Cores: implications for interpreting sediment composition. In Flood, R.D., Piper, D.J.W., Klaus, A., and Peterson, L.C. (Eds.), Proc. ODP, Sci. Results, 155: College Station, TX (Ocean Drilling Pro-gram), 193–215. [PDF]

Barron, J.A., 1985. Late Eocene to Holocene diatom bio-stratigraphy of the equatorial Pacific Ocean, Deep Sea Drilling Project Leg 85. In Mayer, L., Theyer, F., Thomas,


E., et al., Init. Repts. DSDP, 85: Washington (U.S. Govt. Printing Office), 413–456.

Blum, P., 1997. Physical properties handbook: a guide to the shipboard measurement of physical properties of deep-sea cores. ODP Tech. Note, 26 [Online]. Available from World Wide Web: http://www-odp.tamu.edu/publications/tnotes/tn26/INDEX.HTM.

Burckle, L.H., 1972. Late Cenozoic planktonic diatom zones from the eastern equatorial Pacific. In Simonsen, R. (Ed.), First Symposium on Recent and Fossil Marine Dia-toms. Nova Hedwegia Beih., 39:217–246.

Burckle, L.H., 1977. Neogene diatom correlations in the Circum-Pacific. Proc. 1st Int. Congress Pacific Neogene Stratigraphy, 36–39.

Cande, S.C., and Kent, D.V., 1995. Revised calibration of the geomagnetic polarity timescale for the Late Creta-ceous and Cenozoic. J. Geophys. Res., 100:6093–6095. doi:10.1029/94JB03098

Channell, J.E.T., Labs, J., and Raymo, M.E., 2003. The Reunion Subchronzone at ODP Site 981 (Feni Drift, North Atlantic). Earth Planet. Sci. Lett., 215:1–12. doi:10.1016/S0012-821X(03)00435-7

Channell, J.E.T., Mazaud, A., Sullivan, P., Turner, S., and Raymo, M.E., 2002. Geomagnetic excursions and pale-ointensities in the Matuyama Chron at ODP Sites 983 and 984 (Iceland Basin). J. Geophys. Res., 107. doi:10.1029/2001JB000491

Curry, W.B., Shackleton, N.J., Richter, C., et al., 1995. Proc. ODP, Init. Repts., 154: College Station, TX (Ocean Drill-ing Program).

de Kaenel, E., Siesser, W.G., and Murat, A., 1999. Pleis-tocene calcareous nannofossil biostratigraphy and the western Mediterranean sapropels, Sites 974 to 977 and 979. In Zahn, R., Comas, M.C., and Klaus, A. (Eds.), Proc. ODP, Sci. Results, 161: College Station, TX (Ocean Drill-ing Program), 159–183. [HTML]

Droser, M.L., and Bottjer, D.J., 1986. A semiquantitative field classification of ichnofabric. J. Sediment. Petrol., 56:558–559.

Ellis, D.V., 1987. Well Logging for Earth Scientists: New York (Elsevier).

Gersonde, R., Hodell, D.A., Blum, P., et al., 1999. Proc. ODP, Init. Repts., 177 [CD-ROM]. Available from: Ocean Drill-ing Program, Texas A&M University, College Station, TX 77845-9547, U.S.A. [HTML]

Gieskes, J.M., Gamo, T., and Brumsack, H., 1991. Chemical methods for interstitial water analysis aboard JOIDES Resolution. ODP Tech. Note, 15 [Online]. Available from World Wide Web: http://www-odp.tamu.edu/publi-cations/tnotes/tn15/f_chem1.htm.

Goldberg, D., 1990. Test performance of the Ocean Drilling Program wireline heave motion compensator. Sci. Drill., 1:206–209.

Goldberg, D., 1997. The role of downhole measurements in marine geology and geophysics. Rev. Geophys., 35:315–342. doi:10.1029/97RG00221

Goll, R.M., and Bjørklund, K.R., 1989. A new radiolarian biostratigraphy for the Neogene of the Norwegian Sea: ODP Leg 104. In Eldholm, O., Thiede, J., Taylor, E., et

23

http://www-odp.tamu.edu/publications/178_SR/VOLUME/CHAPTERS/SR178_05.PDF

http://www-odp.tamu.edu/publications/178_SR/VOLUME/CHAPTERS/SR178_05.PDF

http://dx.doi.org/10.1029/94JB03098

http://dx.doi.org/10.1016/S0012-821X(03)00435-7

http://dx.doi.org/10.1029/2001JB000491

http://dx.doi.org/10.1029/97RG00221

http://dx.doi.org/10.1016/S0031-0182(03)00463-2

http://dx.doi.org/10.1016/S0031-0182(03)00463-2

http://dx.doi.org/10.1016/S0025-3227(98)00033-4

http://dx.doi.org/10.1016/S0025-3227(98)00033-4

http://www-odp.tamu.edu/publications/154_SR/04_CHAP.PDF

http://www-odp.tamu.edu/publications/164_SR/chap_31/chap_31.htm

http://www-odp.tamu.edu/publications/155_SR/CHAP_10.PDF

http://www-odp.tamu.edu/publications/tnotes/tn26/INDEX.HTM



http://www-odp.tamu.edu/publications/177_IR/177TOC.HTM

http://www-odp.tamu.edu/publications/tnotes/tn15/f_chem1.htm

http://www-odp.tamu.edu/publications/tnotes/tn15/f_chem1.htm


al., Proc. ODP, Sci. Results, 104: College Station, TX (Ocean Drilling Program), 697–737. [PDF]

Hagelberg, T., Shackleton, N., Pisias, N., and Shipboard Sci-entific Party, 1992. Development of composite depth sections for Sites 844 through 854. In Mayer, L., Pisias, N., Janecek, T., et al., Proc. ODP, Init. Repts., 138 (Pt. 1): College Station, TX (Ocean Drilling Program), 79–85.

Hagelberg, T.K., Pisias, N.G., Shackleton, N.J., Mix, A.C., and Harris, S., 1995. Refinement of a high-resolution, continuous sedimentary section for studying equatorial Pacific Ocean paleoceanography, Leg 138. In Pisias, N.G., Mayer, L.A., Janecek, T.R., Palmer-Julson, A., and van Andel, T.H. (Eds.), Proc. ODP, Sci Results, 138: Col-lege Station, TX (Ocean Drilling Program), 31–46.

Harms, J.C., and Choquette, P.W., 1965. Geologic evalua-tion of a gamma-ray porosity device. Trans. SPWLA 6th Ann. Logging Symp.: Dallas, C1–C37.

Haslett, S.K., 1994. Plio–Pleistocene radiolarian biostratig-raphy and paleoceanography of the mid-latitude North Atlantic (DSDP Site 609). Geol. Mag., 131:57–66.

Haslett, S.K., 2004. Late Neogene–Quaternary radiolarian biostratigraphy: a brief review. J. Micropaleontol., 23:39–47.

Hayward, B.W., 2001. Global deep-sea extinctions during the Pleistocene ice-ages. Geology, 29:599–602. doi:10.1130/0091-7613(2001)029<0599:GDSEDT>2.0.CO;2

Hilgen, F.J., Krijgsman, W., Langereis, C.G., Lourens, L.J., Santarelli, A., and Zachariasse, W.J., 1995. Extending the astronomical (polarity) time scale into the Miocene. Earth Planet. Sci. Lett., 136:495–510. doi:10.1016/0012-821X(95)00207-S

Hilgen, F.J., Krijgsman, W., Raffi, I., Turco, E., and Zachari-asse, W.J., 2000. Integrated stratigraphy and astronomi-cal calibration of the Serravallian/Tortonian boundary section at Monte Gibliscemi (Sicily, Italy). Mar. Micropal-eontol., 38:181–211. doi:10.1016/S0377-8398(00)00008-6

Hodell, D.A., Curtis, J.H., Sierro, F.J., and Raymo, M.E., 2001. Correlation of late Miocene to early Pliocene sequences between the Mediterranean and North Atlan-tic. Paleoceanogr., 16:164–178. doi:10.1029/1999PA000487

Jansen, E., Raymo, M.E., Blum, P., et al., 1996. Proc. ODP, Init. Repts., 162: College Station, TX (Ocean Drilling Pro-gram).

Jorissen, F.J., de Stigter, H.C., and Widmark, J.G.V., 1995. A conceptual model explaining benthic foraminiferal microhabitats. Mar. Micropaleontol., 26:3–15. doi:10.1016/0377-8398(95)00047-X

Kennett, J.P., and Srinivasan, M.S., 1983. Neogene Plank-tonic Foraminifera: A Phylogenetic Atlas: Stroudsburg, PA (Hutchinson Ross).

Koç, N., Hodell, D.A., Kleiven, H., and Labeyrie, L., 1999. High–resolution Pleistocene diatom biostratigraphy of Site 983 and correlations with isotope stratigraphy. In Raymo, M.E., Jansen, E., Blum, P., and Herbert, T.D. (Eds.), 1999. Proc. ODP, Sci. Results, 162: College Station, TX (Ocean Drilling Program), 51–62. [HTML]


Koizumi, I., 1973. The late Cenozoic diatoms of Sites 183–193, Leg 19 Deep Sea Drilling Project. In Creager, J.S., Scholl, D.W., et al., Init. Repts. DSDP, 19: Washington (U.S. Govt. Printing Office), 805–855.

Krijgsman, W., Hilgen, F.J., Langereis, C.G., Santaralli, A., and Zachariasse, W.J., 1995. Late Miocene magneto-stratigraphy, biostratigraphy and cyclostratigraphy in the Mediterranean. Earth Planet. Sci. Lett., 136:475–494. doi:10.1016/0012-821X(95)00206-R

Lamont-Doherty Earth Observatory-Borehole Research Group, 1994. Wireline Logging Services Guide [Online]. Available from World Wide Web: http://www.ldeo.columbia.edu/BRG/ODP/LOGGING/.

Lazarus, D., and Pallant, A., 1989. Oligocene and Neogene radiolarians from the Labrador Sea, ODP Leg 105. In Srivastava, S.P., Arthur, M.A., Clement, B., et al., Proc. ODP, Sci. Results, 105: College Station, TX (Ocean Drill-ing Program), 349–380.

Loeblich, A.R., and Tappan, H., 1988. Foraminiferal Genera and Their Classification (Vol. 1 and 2): New York (Van Nostrand Reinhold Co.).

Lourens, L.J., Antonarakou, A., Hilgen, F.J., Van Hoof, A.A.M., Vergnaud-Grazzini, C., and Zachariasse, W.J., 1996. Evaluation of the Plio–Pleistocene astronomical timescale. Paleoceanography, 11:391–413.

Lovell, M.A., Harvey, P.K., Brewer, T.S., Williams, C., Jack-son, P.D., and Williamson, G., 1998. Application of FMS images in the Ocean Drilling Program: an overview. In Cramp, A., MacLeod, C.J., Lee, S.V., and Jones, E.J.W. (Eds.), Geological Evolution of Ocean Basins: Results from the Ocean Drilling Program. Geol. Soc. Spec. Publ., 131:287–303.

Luthi, S.M., 1990. Sedimentary structures of clastic rocks identified from electrical borehole images. In Hurst, A., Lovell, M.A., and Morton, A.C. (Eds.), Geological Applica-tions of Wireline Logs. Spec. Publ.—Geol. Soc. London, 48:3–10.

Lyle, M., Koizumi, I., Richter, C., et al., 1997. Proc. ODP, Init. Repts., 167: College Station, TX (Ocean Drilling Pro-gram). [PDF]

Manheim, F.T., and Sayles, F.L., 1974. Composition and origin of interstitial waters of marine sediments, based on deep sea drill cores. In Goldberg, E.D. (Ed.), The Sea (Vol. 5): Marine Chemistry: The Sedimentary Cycle: New York (Wiley), 527–568.

Martini, E., 1971. Standard Tertiary and Quaternary calcar-eous nannoplankton zonation. In Farinacci, A. (Ed.), Proc. 2nd Int. Conf. Planktonic Microfossils Roma: Rome (Ed. Tecnosci.), 2:739–785.

Mazzullo, J.M., Meyer, A., and Kidd, R.B., 1988. New sedi-ment classification scheme for the Ocean Drilling Pro-gram. In Mazzullo, J.M., and Graham, A.G. (Eds.), Handbook for shipboard sedimentologists. ODP Tech. Note, 8:45–67.

Mix, A.C., Tiedemann, R., Blum, P., et al., 2003. Proc. ODP, Init. Repts., 202 [CD-ROM]. Available from: Ocean Drill-ing Program, Texas A&M University, College Station TX 77845-9547, USA. [HTML]

Moran, K., 1997. Elastic property corrections applied to Leg 154 sediment, Ceara Rise. In Shackleton, N.J., Curry,

24

http://dx.doi.org/10.1130/0091-7613(2001)029<0599:GDSEDT>2.0.CO;2

http://dx.doi.org/10.1016/0012-821X(95)00207-S

http://dx.doi.org/10.1016/0012-821X(95)00207-S

http://dx.doi.org/10.1016/S0377-8398(00)00008-6

http://dx.doi.org/10.1016/S0377-8398(00)00008-6

http://dx.doi.org/10.1029/1999PA000487

http://dx.doi.org/10.1029/1999PA000487

http://dx.doi.org/10.1016/0377-8398(95)00047-X

http://dx.doi.org/10.1016/0012-821X(95)00206-R


http://www.ldeo.columbia.edu/BRG/ODP/LOGGING/

http://www.ldeo.columbia.edu/BRG/ODP/LOGGING/



http://www-odp.tamu.edu/publications/104_SR/VOLUME/CHAPTERS/sr104_35.pdf


W.B., Richter, C., and Bralower, T.J. (Eds.), Proc. ODP, Sci. Results, 154: College Station, TX (Ocean Drilling Pro-gram), 151–155. [PDF]

Munsell Color Company, 1992. Munsell Soil Color Charts, Newburgh, NY (MacBeth Division of Kollmorgen Instruments Corp.).

Murray, R.W., Miller, D.J., and Kryc, K.A., 2000. Analysis of major and trace elements in rocks, sediments, and inter-stitial waters by inductively coupled plasma–atomic emission spectrometry (ICP-AES). ODP Tech. Note, 29 [Online]. Available from World Wide Web: http://www-odp.tamu.edu/publications/tnotes/tn29/INDEX.HTM.

Pimmel, A., and Claypool, G., 2001. Introduction to ship-board organic geochemistry on the JOIDES Resolution. ODP Tech. Note, 30 [Online]. Available from World Wide Web: http://www-odp.tamu.edu/publications/tnotes/tn30/INDEX.HTM.

Raffi, I., and Flores, J.-A., 1995. Pleistocene through Mio-cene calcareous nannofossils from eastern equatorial Pacific Ocean. In Pisias, N.G., Mayer, L.A., Janecek, T.R., Palmer-Julson, A., and van Andel, T.H. (Eds.), Proc. ODP, Sci. Results, 138: College Station, TX (Ocean Drilling Program), 233–286.

Rider, M.H., 1996. The Geological Interpretation of Well Logs (2nd ed.): Caithness (Whittles Publishing).

Ruddiman, W.F., Cameron, D., and Clement, B.M., 1987. Sediment disturbance and correlation of offset holes drilled with the hydraulic piston corer: Leg 94. In Rud-diman, W.F., Kidd, R.B., Thomas, E., et al., Init. Repts. DSDP, 94 (Pt. 2): Washington (U.S. Govt. Printing Office), 615–634.

Salimullah, A.R.M., and Stow, D.A.V., 1992. Application of FMS images in poorly recovered coring intervals: exam-ples from ODP Leg 129. In Hurst, A., Griffiths, C.M., and Worthington, P.F. (Eds.), Geological Application of Wire-line Logs II. Geol. Soc. Spec. Publ., 65:71–86.

Sato, T., Kameo, K., and Mita, I., 1999. Validity of the latest Cenozoic calcareous nannofossil datums and its appli-cation to the tephrochronology. Earth Sci., 53:265–274.

Schlumberger, 1989. Log Interpretation Principles/Applica-tions: Houston (Schlumberger Educ. Services), SMP–7017.

Schlumberger, 1994. Log Interpretation Charts: Sugarland, TX (Schlumberger Wireline and Testing), SMP-7006.

Schrader, H.J., and Gersonde, R., 1978. Diatoms and silico-flagellates. In Zachariasse, W.J., et al. (Eds.), Micropaleon-tological Counting Methods and Techniques: An Exercise of an Eight Metres Section of the Lower Pliocene of Cap Ros-sello, Sicily. Utrecht Micropaleontol. Bull., 17:129–176.

Schultheiss, P.J., and McPhail, S.D., 1989. An automated P-wave logger for recording fine-scale compressional wave velocity structures in sediments. In Ruddiman, W., Sarn-thein, M., et al., Proc. ODP, Sci. Results, 108: College Sta-tion, TX (Ocean Drilling Program), 407–413. [PDF]

Serra, O., 1984. Fundamentals of Well-Log Interpretation (Vol. 1): The Acquisition of Logging Data: Dev. Pet. Sci., 15A: Amsterdam (Elsevier).


Serra, O., 1986. Fundamentals of Well-Log Interpretation (Vol. 2): The Interpretation of Logging Data. Dev. Pet. Sci., 15B: Amsterdam (Elsevier).

Serra, O., 1989. Formation MicroScanner Image Interpretation: Houston (Schlumberger Educ. Services), SMP-7028.

Shackleton, N.J., Crowhurst, S., Hagelberg, T., Pisias, N.G., and Schneider, D.A., 1995. A new late Neogene time scale: application to Leg 138 sites. In Pisias, N.G., Mayer, L.A., Janecek, T.R., Palmer-Julson, A., and van Andel, T.H. (Eds.), Proc. ODP, Sci. Results, 138: College Station, TX (Ocean Drilling Program), 73–101.

Shipboard Scientific Party, 2000. Explanatory notes. In Sacks, I.S., Suyehiro, K., Acton, G.D., et al., Proc. ODP, Init. Repts., 186, 1–51 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Sta-tion TX 77845-9547, USA. [HTML]

Shipboard Scientific Party, 2003a. Explanatory notes. In Mix, A.C., Tiedemann, R., Blum, P., et al., Proc. ODP, Init. Repts., 202, 1–76 [CD_ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Sta-tion TX 77845-9547, USA. [HTML]

Shipboard Scientific Party, 2003b. Explanatory notes. In Wil-son, D.S., Teagle, D.A.H., Acton, G.D., Proc. ODP, Init. Repts., 206, 1–94 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Sta-tion TX 77845-9547, USA. [HTML]

Sierro, F.J., Hilgen, F.J., Krijgsman, W., and Flores, J.A., 2001. The Abad composite (SE Spain): a Messinian refer-ence section for the Mediterranean and the APTS. Paleo-geogr., Paleoclimatol., Paleoecol., 168:141–169. doi:10.1016/S0031-0182(00)00253-4

Sierro, F.J., Flores, J.A., Civis, J., González-Delgado, J.A., and Frances, G., 1993. Late Miocene globorotaliid event-stratigraphy and biogeography in the NE-Atlantic and Mediterranean. Mar. Micropaleontol., 21:143–168. doi:10.1016/0377-8398(93)90013-N

Spezzaferri, S., 1998. Planktonic foraminifer biostratigra-phy and paleoenvironmental implications of Leg 152 sites (East Greenland Margin). In Saunders, A.D., Larsen, H.C., and Wise, S.W., Jr. (Eds.), Proc. ODP, Sci. Results, 152: College Station, TX (Ocean Drilling Program), 161–189. [PDF]

Takayama, T., and Sato, T., 1987. Coccolith biostratigraphy of the North Atlantic Ocean, Deep Sea Drilling Project Leg 94. In Ruddiman, W.F., Kidd, R.B., Thomas, E., et al., Init. Repts. DSDP, 94 (Pt. 2): Washington (U.S. Govt. Printing Office), 651–702.

Takayama, T., and Sato, T., 1993–1995. Coccolith biostra-tigraphy of the Pliocene/Pleistocene boundary strato-type. Ann. Geol. Pays Hell., 36:143–150.

Thomas, R.G., Guyodo, Y., and Channell, J.E.T., 2003. U channel track for susceptibility measurements. Geochem., Geophys., Geosyst., 4(6). doi:10.1029/2002GC000454

Wang, P., Prell, W.L., Blum, P., et al., 2000. Proc. ODP, Init. Repts., 184 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Station TX 77845-9547, USA. [HTML]

Weaver, P.P.E., and Clement, B.M., 1987. Magnetobio-stratigraphy of planktonic foraminiferal datums, DSDP

25

http://dx.doi.org/10.1016/S0031-0182(00)00253-4

http://dx.doi.org/10.1016/0377-8398(93)90013-N

http://dx.doi.org/10.1029/2002GC000454

http://dx.doi.org/10.1029/2002GC000454

http://www-odp.tamu.edu/publications/154_SR/08_CHAP.PDF





http://www-odp.tamu.edu/publications/186_IR/chap_02/chap_02.htm





http://www-odp.tamu.edu/publications/108_SR/VOLUME/CHAPTERS/sr108_24.pdf

http://www-odp.tamu.edu/publications/152_SR/VOLUME/CHAP_12.PDF


Leg 94, North Atlantic. In Ruddiman, W.F., Kidd, R.B., Thomas, E., et al., Init. Repts. DSDP, 94: Washington (U.S. Govt. Printing Office), 815–829.

Wentworth, C.K., 1922. A scale of grade and class terms of clastic sediments. J. Geol., 30:377–392.

Westberg-Smith, M.J., and Riedel, W.R., 1984. Radiolarians from the western margin of the Rockall Plateau: Deep Sea Drilling Project Leg 81. In Roberts, D.G., Schnitker,


D., et al., Init. Repts. DSDP, 81: Washington (U.S. Govt. Printing Office), 479–501.

Zachos, J.C., Kroon, D., Blum, P., et al., 2004. Proc. ODP, Init. Repts., 208 [CD-ROM]. Available from: Ocean Drill-ing Program, Texas A&M University, College Station TX 77845-9547, USA. [HTML]

Publication: 9 September 2006MS 306-110

26



Figure F1. Ternary diagram showing nomenclature for principal components of whole sediment composition.

Calcareous oozeSiliceous

calcareous ooze Calcareous

siliceous ooze Siliceous ooze

Calcareousooze "with"

textural minormodifier

Siliceous calcareousooze "with"


Calcareoussiliceous

ooze "with"textural minor

modifier

Siliceousooze "with"


Clayey/silty/sandycalcareous

ooze

Clayey/silty/sandysiliceous

calcareousooze

Clayey/silty/sandycalcareoussiliceous

ooze

Clayey/silty/sandysiliceous

ooze

Calcar-eous

majormodifier

100% 75% 50% 75% 100%

90%

75%

50%

75%

Siliciclastic100%

50%

75%

75%

90%

90%90%

Siliceousmajormodifier

Silic-eous

calcar-eous

majormodifier

Calcar-eous

siliceousmajor

modifier

Texturalname "with"

minor biogenicmodifier

Clay/silt/

sand

Calcareous Siliceous

Proc. IODP | Volume 303/306 27


Figure F2. Grain-size classification scheme of Wentworth (1922).

1/2

1/4

1/8

1/16

1/32

1/64

1/128

1/256

2.00

1.00

0.50

0.25

0.125

0.0625

0.031

0.0156

0.0078

0.0039

0.00006

15.6

-12.0

-8.0

-6.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

14.0

Boulder

Cobble

Pebble

Granule

Very coarse sand

Coarse sand

Medium sand

Fine sand

Very fine sand

Coarse silt

Medium silt

Fine silt

Very fine silt

Gra

vel

San

dS

ilt

4096

256

64

4

63

500500

250

125

31

7.8

3.9

0.06

Conglomerate/Breccia

Sandstone

Siltstone

Millimeters (mm) Micrometers (µm) Phi (φ) Wentworth size class Rock type

Clay

Mud Claystone



Figure F3. Ternary diagram showing nomenclature for siliciclastic sediment components based on grain size.

25

75 25

75

Clay

Clay

SiltSand

5050

2020

20

Siltyclay

Clayeysilt

Sandysilt

Siltysand

Clayeysand

Sandyclay

Sand-silt-clay

Sand Silt25 7550



Figure F4. Example of an AppleCORE summary barrel sheet.

Site U1314 Hole A Core 7H Cored 49.4-58.9 mbsf

1

2

3

4

5

6

7

8

9

10

ME

TE

RS

12

34

56

78

SE

CT

ION

GR

AP

HIC

LIT

H.

BIO

TU

RB

.

STR

UC

TUR

E

AC

CE

SS

OR

IES

DIS

TU

RB

.

SS

SS

SS

SS

PAL

SA

MP

LE

dk GY

dk gn GY

dk GY

gn GY

GY

dk gn GY

GY

dk GY

GY

gn GY

dk GY

CO

LOR

Dominant Lithologies: NANNOFOSSIL SILTY CLAY WITH DIATOMS, dark gray (5Y 4/1), SILTY CLAY WITH FORAMINIFERS AND NANNOFOSSILS, dark gray (5Y 4/1), SILTY CLAY NANNOFOSSIL OOZE, dark greenish gray (5GY 4/1) and greenish gray (5GY 5/1), SILTY CLAY NANNOFOSSIL OOZE WITH DIATOMS, greenish gray (5G 6/1, 5G 5/1, 5Y 5 / 1 ) .

Alternating terrigenous- and biogenic-rich succession. Occasional diffuse mm- to cm-scale bands/laminae or mottles of dark gray (5Y 4/1), gray (5Y 5/1), greenish gray (5GY 5/1, 5G 4/2, 5G 5/1), dark greenish gray (5G 4/1-2), olive gray (5Y 5/2), olive (5Y 4/3), pale green (5G 6/2), medium gray (N5); color bands occur in most sections.

Bioturbation rare to abundant, with dm-scale alternation between degrees of bioturbation; mm- to cm-scale burrows present; mottled appearance throughout, sometimes extensive. Streaks of pyrite occur in each section, especially localized near burrows. Contacts between dominant and minor lithologies and diffuse color bands often gradational or bioturbated.

Dropstones occurs in sections 1 (at 1, 2, and 17 cm, all of them in a soupy interval) and 5 (at 143 cm).

Moderate drilling disturbance in the form of soupy sediments at Section 1, 0-51 cm.

DESCRIPTION



Figure F5. Key to symbols used for graphic lithologies.

Siliciclastic sediments Pelagic sediments

Contacts

Nannofossil ooze

Foraminifer ooze

Calcareous ooze

Diatom ooze

Biosiliceous ooze

Sharp

Scoured

Bioturbated

Uncertain

Gradational

Undulating

Sand or sandstone

Silty sand

Clayey sand

Silt or siltstone

Sandy silt

Clayey silt

Silty clay

Clay or claystone

Sand-silt-clay

Gravel

Conglomerate



Figure F6. Key to other symbols used on the AppleCORE summary barrel sheets.

Core disturbance

Bioturbation intensity

Ichnofossils Sample type

Lithologic accessories

Sedimentary structure

Highly fragmented

Biscuit

Breccia

Gas expansion

Orientation unknown

Slurry

Flow-in

Soupy

Deformed

Disturbed

Fractured

Current ripple Planar lamination

Pebbles/Granules

Mottled mudclasts

Mud clasts

Dropstone

Lithoclast

Thin ash layer

Mottled

Pyrite

Pumice

Breccia horizon

Rip-up clasts

Shell fragments

Pyrite concretionBurrow

Fossil ghost

Nodule/concretion(general)

Isolated lamina

Silty lamina

Sandy lamina

Microfault (normal)

Microfault (thrust)

Cross lamination

Coarsening upward

BrecciaPebbles/Granules/Sand

Mud cracks Scour

Fault

Slump

Fining upward

Chaotic bedding

Planar tabularbedding

Reverse gradedbedding

Graded bedding

Wavy parallelbedding

Zoophycos

Gastropods

None/low High

Chondrites

Thalassinoides

Undefined foraminifer Smear slide MicropaleontologySS PAL

Pelagic foraminifer X-ray diffractionInterstitial waterIW XRD



Figure F7. Key to ichnofabric index (bioturbation intensity) used during Expedition 306 (modified fromDroser and Bottjer, 1991).

No bioturbation

Rare bioturbation

Moderatebioturbation10%~50%

Strong (common to abundant)bioturbation>50%

Totally bioturbated(homogeneous)

0%~10%

Bio

turb

atio

n in

tens

ity

Low

High


Proc. IOD

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306 Scientists

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1315 meth

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s

on, and biohorizons used during Expe- first rare occurrence, LO = last occur-

High latitude Atlantic (ODP Leg 162)compiled by Koç et al. (1999)

LO P. curvirostris (0.3)LO T. jouseae (0.30/0.31)

LO F. reinholdii (0.59/0.60)

LO Nd. seminae (0.84/0.85)

FO F. doliolus (1.89)

FO Nd. seminae (1.25/1.26)

FO P. curvirostris (1.52/1.53)

LO F. fossilis (0.68/0.69)

elicata

LO C. yabei

LO D. praedimorpha

LO D. punctata var.hustedii

FO R. barboi

LO D. kamtschatica(Koizumi 1973, N. Pacific)

FO N. kamtschatica(Akiba & Yanagisawa 1986,N. Pacific)

Diatoms

Event

Thalassiosira oestrupii

Proboscia curvirostris

Neodenticula seminae

Fragilariopsis reinholdii

Rhizosoleniapraebarboi

Rhizosoleniabarboi

Denticulopsispraedimorpha

Coscinodiscus yabei

Figure F8. Correlation of geomagnetic polarity timescale (Cande and Kent, 1995), biostratigraphic zonatidition 306. FO = first occurrence, FaO = first abundant occurrence, FcO = first common occurrence, FrO =rence, LcO = last common occurrence, Bm = morphotypic first appearance. s = sinistral, d = dextral.

Age

(M

a)

Ple

isto

cene

Mio

cene

late

early

late

Plio

cene

Brunhes

Gau

ssM

atuy

ama

Gilb

ert

n

r

n

r

n

r

n

r

n

r

Calcareous Nannofossils

Top small Reticulofenestra interval (7.10) FO A. primus (7.392)

FO D. berggrenii (8.281) FO D. loeblichii (8.43)

Base small Reticulofenestra interval(8.788)

LO D. hamatus (9.635) FO M. convallis (9.43)

FO D. neohamatus (10.45) FO D. hamatas (10.476)

FO C. coalitus (10.794)

FO D. kugleri (11.831)

LO D. kugleri (11.52)

FO E. huxleyi (0.25) LO H. inversa (0.16)

LO P. lacunosa (0.41) FO H. inversa (0.51)

LO R. asanoi (0.85) FO G. parallela (0.95)

FO R. asanoi (1.16) LO Large Gephyrocapsa spp. (1.21) LO H. sellii (1.27) FO Large Gephyrocapsa spp. (1.45)

FO G. oceanica (1.65) FO G. caribbeanica (1.73)

LO D. brouweri (1.97)

LO D. pentaradiatus (2.38) LO D. surculus (2.54)

LO D. tamalis (2.74) LO R. ampla (2.78)

LO R. pseudoumbilicus (3.85)

LO Sphenolithus spp. (3.65)

FO A. amplificus (6.84)

LO D. quinqueramus (5.537)

FO C. rugosus (5.089)

LO Amaurolithus spp. (4.50)

n

r

Radiolarianscompiled from Westberg-Smith and

Riedel (1984), and Haslett (1994, 2004)

LO S. universus (0.27/0.6)

LO A. nosicaae (0.6-0.8)

FO P. hertwigii (0.8/0.94)LO L. neoheteroporos(1.06/1.17)

FO L. neoheteroporos(2.07/2.24)

FO C. davisiana (2.24/2.44)

LO S. peregrina (2.79/2.94)

Bm S. langii

LO F. reinholdii

FO F. doliolus

FO T. convexa

LO F. jouseae

FO F. jouseae

FO T. oestrupiiLO T. miocenica

LO T. convexa

LO C. plicatus

LO C. moronensis

LO Cr. coscinodiscus

LO C. temperei var. d

FO T. miocenica

FO H. cuneiformis

LO A. amplificus (5.999)

mid

dle

n

n

n

r

r

r

Planktonc foraminifers

FO G. inflata (2.09)

FO N. pachyderma (s) encrusted (1.78)

FO G. truncatulinoides (2.08)

LO G. miocenica (2.4)LO N. atlantica (2.41)LO G. puncticulata (2.41)

Bottom acme N. atlantica

Alternating s/d N. acostaensis

LcO G. miotumida group (6.3)First s/d coiling N. acostaensis(6.3)

FaO G. margaritae (6.0)

LO G. nepenthes

FO G. crassaformisFO G. puncticulata (4.52)

LcO G. margaritae (3.98)LO G. margaritae (3.81)

Disappearance G. hirsutm (3.18)LO S. seminulina (3.19)

Replacement G. menardii/G. miotumida (7.24)FcO G. menardii (d) (7.35)s/d coiling change G. scitulaLcO G. menardii (s) (7.51)

N. acostaensis preferentially (s)(7.8-6.3)

FrO N. acostaensis s.s. (10.55)in Neogloboqadrina sp.

LO N. mayeri (11.2)

d/s coiling change inNeogloboquadrina sp. (10.0)

Alternating s/d coiling (9.2-7.8) inNeogloboquadrina sp.

FO N. humerosa (8.2)

FO G. nepenthes (11.6)

FO C. acutus (5.046)

FO T. rugosus (5.231)

LO C. calyculus (9.641)

FO C. calyculus (10.705)

LO A. primus (4.56)

LO C. coalitus (9.694)

FO C. miopelagicus (10.947)


N. acostaensis (d)



N. acostaensis (d)

Mid-latitude Atlantic (DSDP Leg 94)compiled by Baldauf (1987)

Disappearance G. puncticulata (3.57)

Reappearance G. puncticulata (3.31)

Magnetic polarity(Cande and Kent, 1995) EventEvent

Weaver andClement

(1987)Datums

Zone(Martini,1971) Event

Jaramillo

Olduvai

Kaena

Cochiti

Sidufjall

Thvera

Mammoth

Reunion

Nunivak

NN11A

NN10B

NN10A

NN9

NN8

NN7

NN6

NN11B

NN12

NN13/NN14

NN15

NN16

NN17

NN18

NN19

NN20

NN21

NN11C

NN11D

C1

C2

C2A

C3

C3A

C3B

C4

C4A

C5

G. marga-ritae

N. atlantica

G. puncti-culata

N. pachy-derma (s)encrusted

G. inflata

G. bulloides

G. cono-miozea

N. atlantica (d)/N. acostaensis

N. mayeri /O. suturalis

Fragilariopsisdoliolus

Fragilariopsis reinholdii

Alveusmarinum

Fragilariopsis jouseae

Thalassiosira convexa

Nt. porteri-Nt. miocenica

Coscinodiscus yabei

Coscinodiscus moronensis

Craspedodiscus coscinodiscus

1

2

3

4

5

6

7

8

9

10

11

12

0


Figure F9. IODP paleomagnetic coordinate system for archive halves of core sections.

+z

+y

+x

Top

Bottom

Upcor

e

+x = North

+y = East

+z = Downcore



Figure F10. Comparison of TOC contents determined postcruise at the Alfred Wegener Institute (J. Hefter,unpubl. data, 2006) by two independent methods. Grey line = hypothetical 1:1 correlation.

0.0

TO

C (

wt%

) sh

ip

Hole U1312A

TOC (wt%) shore

0.2 0.4 0.6 0.8 1.00.0

0.2

0.4

0.6

0.8

1.0

Hole U1313A

Hole U1314A



Figure F11. Configuration of the wireline logging tool strings used during IODP Expedition 306.

Telemetry

HNGSHostile EnvironmentGamma Ray Sonde

APSAccelerator Porosity Sonde

HLDSHostile EnvironmentLitho-Density Sonde

Caliper

Cablehead

Eccentralizingbow spring

DIT-E Dual Induction Tool

model E

TAP Temperature/Acceleration/

Pressure tool

Cablehead

Telemetry

Centralizer

DSIDipole Sonic Imager

FMSFormation MicroScanner

GPITGeneral PurposeInclinometer Tool

Centralizer

SGTScintillation Gamma Ray

Tool

MGTMulti-Sensor Spectral

Gamma Ray Tool

0.00 m

38.60 m

0.00 m

32.34 m

Tool Zero Tool Zero



Table T1. Calcareous nannofossil events.

Notes: LO = last occurrence, FO = first occurrence.

Species event Zone (base)Age(Ma) Reference

LO Helicosphaera inversa NN21 0.16 Sato et al., 1999FO Emiliania huxleyi 0.25 Sato et al., 1999NN20LO Pseudoemiliania lacunosa 0.41 Sato et al., 1999

NN19

FO Helicosphaera inversa 0.51 Sato et al., 1999LO Reticulofenestra asanoi 0.85 Sato et al., 1999FO Gephyrocapsa parallela 0.95 Sato et al., 1999FO Reticulofenestra asanoi 1.16 Sato et al., 1999LO large Gephyrocapsa spp. 1.21 Sato et al., 1999LO Helicosphaera sellii 1.27 Sato et al., 1999FO large Gephyrocapsa spp. 1.45 Sato et al., 1999FO Gephyrocapsa oceanica 1.65 Sato et al., 1999FO Gephyrocapsa caribbeanica 1.73 Sato et al., 1999LO Discoaster brouweri 1.97 Sato et al., 1999NN18LO Discoaster pentaradiatus 2.38 Sato et al., 1999NN17LO Discoaster surculus 2.54 Sato et al., 1999

NN16LO Discoaster tamalis 2.74 Sato et al., 1999LO Reticulofenestra ampla 2.78 Sato et al., 1999LO Sphenolithus spp. 3.65 Raffi and Flores, 1995LO Reticulofenestra pseudoumbilicus 3.85 Sato et al., 1999LO Amaurolithus primus

NN13/NN144.56 Shackleton et al., 1995

LO Ceratolithus acutus 5.046 Backman and Raffi, 1997FO Ceratolithus rugosus 5.089 Backman and Raffi, 1997LO Triquetrorhabdulus rugosus NN12 5.231 Backman and Raffi, 1997LO Discoaster quinqueramus 5.537 Backman and Raffi, 1997NN11DLO Amaurolithus amplificus 5.999 Backman and Raffi, 1997NN11CFO Amaurolithus amplificus 6.84 Backman and Raffi, 1997Top small Reticulofenestra interval NN11B 7.10 Backman and Raffi, 1997FO Amaurolithus primus 7.392 Backman and Raffi, 1997NN11AFO Discoaster berggrenii 8.281 Backman and Raffi, 1997FO Discoaster loeblichii NN10B 8.43 Raffi and Flores, 1995Base small Reticulofenestra interval 8.788 Backman and Raffi, 1997FO Minylitha convallis NN10A 9.43 Raffi and Flores, 1995LO Discoaster hamatus 9.635 Backman and Raffi, 1997LO Catinaster calyculus

NN99.641 Backman and Raffi, 1997

LO Catinaster coalitus 9.694 Backman and Raffi, 1997FO Discoaster neohamatus 10.45 Backman and Raffi, 1997FO Discoaster hamatus 10.476 Backman and Raffi, 1997FO Catinaster calyculus NN8 10.705 Backman and Raffi, 1997FO Catinaster coalitus 10.794 Backman and Raffi, 1997LO Coccolithus miopelagicus

NN710.947 Backman and Raffi, 1997

LO Discoaster kugleri 11.52 Backman and Raffi, 1997FO Discoaster kugleri 11.831 Backman and Raffi, 1997


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ccurrence, FrO = first rare occurrence. d = dextral, s = sinistral.

Reference Region

Clement, 1987 N. Atlantic

1998 N. Atlantic Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987 N. Atlantic Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987 N. Atlantic Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterraneanl., 1996 Mediterraneanl., 1996 Mediterranean Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987; Lourens et al., 1996 N. Atlantic, Mediterranean Clement, 1987 Mediterranean Clement, 1987 Mediterranean, 1993 N. Atlantic., 2001 N. Atlantic

, 1993, 2001; Hilgen et al., 1995; Krijgsman et al., 1995 Atlantic, Mediterranean

, 1993; Krijgsman et al., 1995 Atlantic, Mediterreanean

, 1993; Krijgsman et al., 1995 Atlantic, 1993 Atlantict al., 1995; Sierro et al., 1993 Mediterranean, Atlantict al., 1999 Mediterranean 1998 N. Atlantict al., 1999 Mediterranean., 2000 Mediterranean., 2000 Mediterranean., 2000 Mediterranean 1998 N. Atlantic

Table T2. Planktonic foraminifer stratigraphic events.

Notes: FO = first occurrence, LO = last occurrence, LcO = last common occurrence, FcO = first common o

Species eventAge(Ma) Polarity interval

FO Neogloboquadrina pachyderma (s) (encrusted)

1.78 Top Olduvai Weaver and

FO Globorotalia truncatulinoides 2.08 Base Olduvai Spezzaferri,FO Globorotalia inflata 2.09 Base Olduvai–Reunion Weaver andLO Globorotalia miocenica 2.4 Reunion–Gauss/Matuyama Weaver andLO Neogloboquadrina atlantica 2.41 Reunion–Gauss/Matuyama Weaver andLO Globorotalia puncticulata 2.41 Reunion–Gauss/Matuyama Weaver andDisappearance Globorotalia hirsuta 3.18 Base Kaena–top Mammoth Weaver andLO Sphaeroidinellopsis seminulina 3.19 Base Kaena–top Mammoth Weaver andReappearance Globorotalia puncticulata 3.31 Lourens et aDisappearance Globorotalia puncticulata 3.57 Lourens et aLO Globorotalia margaritae 3.81 Base Gauss–Cochiti Weaver andLcO Globorotalia margaritae 3.98 Base Gauss–Cochiti Weaver andFO Globorotalia puncticulata 4.52 Nunivak Weaver andFO Globorotalia crassaformis Nunivak Weaver andLO Globgerina nepenthes 4.8–4.89 Sidufjall Weaver andFcO Globorotalia margaritae 6 C3A.1n Sierro et al.Alternating (s/d) Neogloboquadrina acostaensis 6–6.3 Below C3A.1n Hodell et alLcO Globorotalia miotumida group 6.3 Below C3A.1nFirst coiling change Neogloboquadrina

acostaensis (s/d)6.3 Below C3An.1n Sierro et al.

Replacement Globorotalia menardii/Globorotalia miotumida

7.24 Below C3Bn Sierro et al.

FcO Globorotalia menardii (d) 7.35 Below C3Br.1n Sierro et al.Coiling change Globorotalia scitula (s/d) Sierro et al.LcO Globorotalia menardii (s) 7.51 Below C3Br.2n Krijgsman eNeogloboquadrina acostaensis preferentially (s) 6.3–7.8 Krijgsman eFO Neogloboquadrina humerosa 8.2 C4r.2r Spezzaferri,Alternating (s/d) in Neogloboquadrina sp. 7.8–9.2 Krijgsman eCoiling in Neogloboquadrina (d/s) 10 Top C5n.2n Hilgen et alFrO Neogloboquadrina acostaensis s.s. 10.55 C5n.2n Hilgen et alLO Neogloboquadrina mayeri 11.2 Top C5r.2r Hilgen et alFO Globigerina nepenthes 11.6 C5r.3r Spezzaferri,


Table T3. Analytical methods and precisions for interstitial water geochemical measurements.

Note: ICP-AES = inductively coupled plasma–atomic emission spectroscopy.

Table T4. Measurements and specifications for wireline tools.

Notes: All tool and tool string names (except the TAP and MGT tools) are trademarks of Schlumberger. For additional information about toolphysics and use, consult IODP–USIO Science Services, LDEO, at iodp.ldeo.columbia.edu/TOOLS_LABS/tools.html. See Table T5 for expla-nations of acronyms used to describe tool strings and tools. * = not included in each logging run. NA = not applicable.

ParameterPrecision

(%) Method

Cl– 0.1 Titration with AgNO3

SO42– 2.3 Ion chromatography

NH4+ 1.7 Spectrophotometer

Na+ 3.1 ICP-AESK+ 10.8 ICP-AESMg2+ 8.8 ICP-AESCa2+ 6.2 ICP-AESLi+ 2.6 ICP-AESSr2+ 3.6 ICP-AESBa2+ 15.8 ICP-AESMn2+ 2.8 ICP-AESFe2+ 4.5 ICP-AESH3BO3 4.8 ICP-AESH4SiO4 5 ICP-AES

Tool string Tool MeasurementSampling

interval (cm)Approximate vertical

resolution (cm)

Triple combination MGT* Spectral gamma ray 15HNGS‡ Spectral gamma ray 15 51APS Porosity 5 and 15 43HLDT Bulk density 2.5 38DIT-E Resistivity 15 200/150/76TAP Temperature 1 per s NA

Tool acceleration 4 per s NAPressure 1 per s NA

Formation MicroScanner NGT Spectral gamma ray 15 46(FMS)-sonic combination GPIT Tool orientation 0.25 and 15 NA

FMS Microresistivity 0.25 0.5DSI/SDT/LSS/BHC Acoustic velocity 15 107


http://iodp.ldeo.columbia.edu/TOOLS_LABS/tools.html


Table T5. Acronyms and units for wireline tools.

Note: All tool and tool string names (except the TAP tool) are trademarks of Schlumberger. For the complete list of acronyms used in IODP andfor additional information about tool physics and use, consult IODP–USIO Science Services, LDEO, at iodp.ldeo.columbia.edu/TOOLS_LABS/tools.html.

Tool Output Tool name/Explanation of output Unit

APS Accelerator Porosity SondeAPLC Near array porosity (limestone calibrated) %SIGF Formation capture cross section (Sf) Capture unitsSTOF Tool standoff (computed distance from borehole wall) Inches

DIT-E Dual Induction Tool model EIDPH Deep induction resistivity Ω·mIMPH Medium induction resistivity Ω·mSFLU Spherically focused resistivity Ω·m

DSI Dipole Sonic ImagerDTCO Compressional wave delay time (Dt) ms/ftDTSM Shear wave delay time (Dt) ms/ftDTST Stoneley wave delay time (Dt) ms/ft

FMS Formation MicroScannerC1, C2 Orthogonal hole diameters InchesP1AZ Pad 1 azimuth Degrees Spatially oriented resistivity images of borehole wall

GPIT General Purpose Inclinometer ToolDEVI Hole deviation DegreesHAZI Hole azimuth DegreesFx, Fy, Fz Earth’s magnetic field (three orthogonal components) DegreesAx, Ay, Az Acceleration (three orthogonal components) m/s2

HLDT Hostile Environment Litho-Density ToolRHOM Bulk density g/cm3

PEFL Photoelectric effect b/e–

LCAL Caliper (measure of borehole diameter) InchesDRH Bulk density correction g/cm3

HNGS Hostile Environment Gamma Ray SondeHSGR Standard (total) gamma ray gAPIHCGR Computed gamma ray (HSGR minus uranium contribution) gAPIHFK Potassium wt%HTHO Thorium ppmHURA Uranium ppm

NGT Natural Gamma Ray Spectrometry ToolSGR Standard total gamma ray gAPICGR Computed gamma ray (SGR minus uranium contribution) gAPIPOTA Potassium wt%THOR Thorium ppmURAN Uranium ppm

MGT Multi-Sensor Spectral Gamma Ray ToolGR Total gamma radiation gAPI

TAP Temperature/Acceleration/Pressure tool °C, m/s2, psi




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