Lecture 5: Sedimentology: a refresher on rivers, deltas...

Lecture 5: Sedimentology: a refresher on rivers, deltas and shallow 

marine sediments

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Models of Basin Fill

…….two key texts….. CD…..rivers, deserts, estuaries, deltas, shorelines, shelves, deep sea

Examine and reviewthese sedimentary environments……………….

•Briefly•wrtWestern Eire•Allied Sedimentology GEOL440 notes on website

Deltas

Bhattacharya 2006

Bhattacharya 2006

Bhattacharya 2006

Bhattacharya 2006

Peyto Lake Canada

Bhattacharya 2006

Bhattacharya 2006

Bhattacharya 2006

Prograding mouth bar succession

Homogenous mud, finely laminated or bioturbated, marine fauna… representing shelf deposit

Silty/sandy slump sheet… representing redeposited(distal) mouth bar sediment

60-1

50 m

Finely laminated mud, bioturbation, marine fauna, contorted bedding… representing prodelta deposit

Interbedded mud/sand, wave & current ripple x-lam., parallel/lenticular lam., bioturbation,

contorted bedding, possible cut & fill… representing distal mouth bar deposit

Well-sorted sand, planar & ripple x-lam., tangential x-bedding (bar crest); poorly sorted sand/silt, cut & fill, small-scale trough x-bedding (bar back); large

channel fills near top (distributary channel)

Clean sand, low- & high-angle 3D strat.… representing beach & dune deposits

Mississippi delta

Danube Delta

Ganges-Brahmaputra delta, Bangladesh 100 km

Tide‐dominated delta facies successionOrd River delta, Australia

Bioturbated mud passing into interbeddedmud‐silt‐sand, marine fauna

... representing open shelf to prodelta succession

Bidirectional x‐bedded sand, mud drapes, tidalbundles, reactivation surfaces, scours/channel fills

... representing migrating tidal current ridges& inter‐ridge channel fills on delta front

Alternating sand‐silt‐mud, x‐lam., “flaser‐linsen”bedding, small channel fills, brackish‐water fauna 

... representing tidal flat facies on delta plainErosive, FU sand with herringbone x‐strat., mud

drapes, tidal bundles, ripple x‐lamination... representing tidal channel on delta plain

Bhattacharya 2006

Pulham 1989

Delta?Delta type?

Basinal processes?Flow depths?Paleoflow?

Allo and auto cyclic controls

Boyd et al., 2006

Boyd et al., 2006

Major clastic coastal environments

Shoreline accumulation through progradation

Clifton, 2006

Beach - Offshore

Clifton, 2006

TraceFossils

USC website

Body and trace fossils……

Clifton, 2006

Sea‐levelcontrol on facies

Clifton, 2006

Clifton, 2006

Shallow marine/shoreface?Basinal flows?

Cyclicity

Rivers

Bridge, 2006

Rivers ‐channel scale

Bridge, 2006

Bridge, 2006

Bridge, 2006

Bridge, 2006

Bridge, 2006

Bridge, 2006

Williams & Soek, 1993

Channel type?Paleoflow?

Channel stacking?Controls?

References

See GEOL440 Sedimentology lectures (see website)Chapters by Bridge, Bhattacharya, Clifton and Boyd et al., in Facies Models Revisited 

Davies, S.J. and Elliott, T., 1996, Spectral gamma ray characterization of high resolution sequence stratigraphy: Examples from upper Carboniferous fluvio‐deltaic systems, County Clare, Ireland, in Howell, J.A., and Aitken, J.F., eds., High resolution sequence stratigraphy: Innovations and applications: Geological Society of London Special Publication 104, p. 25‐35.Pulham, A.J., 1989, Controls on internal structure and architecture of sandstone bodies within Upper Carboniferous fluvial‐dominated deltas, County Clare, western Ireland, inWhateley, M.K.G., and Pickering, K.T., eds., Deltas: Sites and traps for fossil fuels: Geological Society of London Special Publication 41, p. 179‐203.Williams, H., and Soek, H.F., 1993. Predicting reservoir sandbody orientation from dipmeter data; The use of sedimentary dip profiles from outcrop studies, in Flint, S.S., and Bryant, I.D., eds., The geological modelling of hydrocarbon reservoirs and outcrop analogues: Special Publication of the International Association of Sedimentologists, v. 15, p. 143‐156. 

Next week

•basinal shales, turbiditesand deep‐sea sediments BUT…………………………