AAPPPPEENNDDIIXX AA SEDIMENTARY SEQUENCES

Fichter, L.S. & Poché, D.J., 1993

Fichter, L.S. & Poché, D.J., 1993

Fichter, L.S. & Poché, D.J., 1993

AAPPPPEENNDDIIXX BB DEPOSITIONAL ENVIRONMENTS AND FACIES

Ideal Carbonate Dominated systems TRANSITIONAL MARINE

Allochems & matrix

Tidal Flat (Super- & Intertidal)

Lagoon or Subtidal

Reef Shelf Deep Shelf Basin Floor

Reef Rock (Boundstone)

small patch reefs typical, but see below

Micrites pure; + oo-, pel- & intra micrudite

bio- (all), pel-, oo- compact mound or framework

fossil-, bio-, pelmicrites

typical; sparse bio-

Sparites sparmicrite & micsparite

bio-, oosparite

Dolomites typical in evaporite basins Chert nodular forms nodular forms nodular forms bedded form

Salt / Gypsum typical in arid climates

typical in arid climates

shallow basin

Colour light gray light & dark gray light gray light – medium gray, green, brown

dark gray - black

Sequences or most typical deposit

Supertidal: mudcracks, algal laminations; pure massive micrite;

gypsum

Intertidal: sand bars,

herringbone, flat-pebble

conglomerate, wavy / lenticular

bedding, channels, stromatolites

large variety of interbedded rock

types

micrites & biomicrites

dominant with storm wash-in of

calcarenite, oomicrite &

oosparite

whole shell coquinas

massive mounds of bound fossils

without bedding

may be biomicrite mounds or piles of fossil (spar) hash

hummocky units of bio- & pelmicrite interbedded with

micrite or

thick beds or x-beds of bio- &

oosparite or

megarippled biosparmicrite &

pelmicrite

very even, millimetre scale

laminations or

massive micrites

Typical structures

/ conditions broken, abraded fossil-sand bars

often interbedded with clastics

slumps, debris flows & turbidites

of fossil debris

often interbedded with shale / silt

Fossils stromatoporoids, algal laminates, snails, ostracods

snails, arthropods, clams, sponges

coral, bryozoa, echinoderms,

stromatoporoids, red algae

echinoderms, cephalopods, coral,

brachiopods, arthropods

rare swimming / floating types

Trace fossil community

Glossi-fungites Cruziana prominent

Trypanites Cruziana, burrowed

Zoophycus

Other Birdseye glauconite, phosphate

pyrite

Ideal Clastic Dominated Long Systems

TERRESTRIAL TRANSITIONAL MARINEMeandering River Shelf Sediment

size & texture

Alluvial Fan

Braided River Alluvial plain Channel

Delta Complex

Lagoon or Delta Bay

Beach / Barrier Island

Desert Dunes

Tidal Flat Storm Domin.

Tidal Domin.

Sub-Marine Fan

Deep Shelf, Basin Floor

Breccia v. course;immature

Conglom- erate

course – medium; immature

v. course – medium; immature

mud pebbleat base of point bar

short systemsonly

lag gravels lag gravels wacke congl. in TA

Arenite v. course;immature

v. course – medium; immature

medium –fine; some

matrix

channel mouth sand

bars

storm wash in

beds

medium – coarse; v. clean

quartz sand

fine – medium; v. well sorted

medium

Wacke sandstone

fine sands typical levee & crevasse

splay

flood wash in beds

typical fine –medium

common fine – coarseTABC

Siltstone typical at top of point bar sequence

levee & crevasse

splay

typical typical typical typicalT

common in small FUS D

Shale usually silty bay fill typical typical typical typicalTE

typical

Colour red, pink,brown

red, pink, brown, gray

red, tan, brown

red, tan, brown

grey to black; white

grey to black

white white, tan,reddish

grey to black

greenish to tan

greenish to tan

gray to dark gray

dark gray to black

Sequences massivedeposits or thick CUS

& FUS cycles

unsorted, unstratified debris

flows

laminated silts with thin

crevasse splay & levee sands; beds often dip

slightly

Bay: multiple FUS in overall CUS

Lagoon: dark,

organic-rich muds

Swash Zone: parallel

laminations gently dipping

seaward

Shoaling Wave

Zone: most kinds of

ripples & x-beds

v. large-scale x-beds 10’s–100’s

m high

calcrete /

silcrete soils

no one ideal sequence:

wavy, flaser, lenticular, bedding, abundant

small ripples, x-

beds, oscillation

ripples, mudcracks, herringbone

x-bedding

v. large-scale

planar x-beds

thinnly laminated

shales; CUS to

thin silts at top

Structures matrix

supported gravel

grain supported

gravel

climbing ripples

many variants

rippled, x-bedded channel

mouth bar cut by river;

coal cap

Lagoon: storm

wash in from

barrier; lamination or planar

x-beds

if gravel beach, gravel grain-

supported and imbricated

grains v. round and

spherical; x-bed foresets

strongly curved

may be confused with dune or braided river sand

bodies

matrix supported TA gravel;

fluid escape structures; flute, tool

marks

extreme low

energy; low oxygen

Fossils rare treesor

vertebrates

rare trees or vertebrates

plant fragments

tree frag’s, vertebrates

plant frag’s, many sparse invertebrate

types

coquina, brackish animals,

plant frag’s

Tree trunks, coquina

rare vertebrates

diverseabundant

marine vertebrates

sparse marine fossils

rare floaters / swimmers

rare floaters /

swimmers

Trace fossils

Scoyenia, roottraces

Cruziana Skolithos vertebratetracks

Glossi-fungites

Cruziana abundant

Cruziana Nerites Zoophycus

Other slumps,loading

thin coals evaporites common

evaporites (arid)

phosphate, glauconite

phosphate phosphate,pyrite

RREEFFEERREENNCCEESS Atkins, Barbara C. and Johnson, Jeffrey A. (1988): The Earth: Problems and Perspectives,

Blackwell Scientific Publications, Palo Alto.

Collison, J.D. and Thompson, D.B. (1982): Sedimentary Structures, George Allen and Unwin Ltd., London

Klein, C. and Hurlbut, C. S., Jr. (1993): Manual of Mineralogy, Revised 21st Edition, John Wiley & Sons, New York.

Leeder, M.R. (1982): Sedimentology – Process and Product, George Allen and Unwin Ltd., London

Nesse, William D. (1991): Introduction to Optical Mineralogy, Oxford University Press, New York.

Prothero, Donald R. & Schwab, Fred (1996): Sedimentary Geology – An Introduction to Sedimentary Rocks and Stratigraphy, W. H. Freeman and Company, New York.

Ren, P., Bornhold, B. & Prior, D. (1996): Seafloor Morphology and Sediment Processes, Knight Inlet, British Columbia in Sedimentary Geology 103, Elsevier Science B.V., Amsterdam

Tucker, Maurice E. (1996): Sedimentary Rocks in the Field, John Wiley & Sons, New York.