Eyles, Nicholas; Daniels, James; Osterman, Lisa E.; Januszczak, Nicole (1999): Ocean Drilling Program Leg 178 (Antarctic Peninsula); sedimentology of glacially-influenced continental shelf "topsets" and "foresets". Geological Society of America (GSA), Boulder, CO, United States, In: Anonymous, Geological Society of America, 1999 annual meeting, 31 (7), 56, georefid:2001-006844
Abstract:
The glacially-influenced Cenozoic continental margin of Antarctica has a large-scale internal structure that consists of flat-lying "topsets" recording episodic aggradation of the continental shelf, resting on seaward-dipping, wedge-shaped "foresets" formed by the progradation of the continental slope. Ocean Drilling Program Leg 178 (February-April 1998) drilled two sites (1097, 1103) through the outer Antarctic Peninsula Pacific continental shelf into strata no older than late Miocene or early Pliocene (<4.6 Ma). Site 1097 lies on the outer shelf and reached a maximum depth drilled of 420 m below the sea floor (mbsf). Strata consist of thick intervals of massive diamictite, containing large amounts of reworked and abraded marine microfauna, interpreted as tills produced by subglacial re-working of marine sediments. Tills are separated by bioturbated muds with dropstones and contain a diverse in situ fauna. The sedimentary record at Site 1097 is consistent with aggradation of a "topset" by till deposition alternating with open marine sedimentation. Site 1103, close to the shelf edge, reached a depth of 363 mbsf through massive and chaotically-stratified diamictites with graded siltstones consistent with deposition on a slope "foreset" and progradation of the continental slope by deposition of debrites and turbidites.
Coverage:
West: -77.3000 East: -56.3000 North: -63.0000 South: -77.0000
West: NaN East: NaN North: NaN South: NaN
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