Sedimentary patterns in the late Quaternary Southern Ocean

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doi: 10.1016/j.dsr2.2007.07.025
Author(s): Diekmann, Bernhard
Author Affiliation(s): Primary:
Alfred Wegener Institute for Polar and Marine Research, Potsdam, Federal Republic of Germany
Other:
Indiana University-Purdue University Indianapolis, United States
University of Salamanca, Spain
Volume Title: Paleoceanography and paleoclimatology of the Southern Ocean; a synthesis of three decades of scientific ocean drilling
Volume Author(s): Warnke, Detlef, editor; Filippelli, Gabriel M.; Flores, José-Abel
Source: Paleoceanography and paleoclimatology of the Southern Ocean; a synthesis of three decades of scientific ocean drilling, edited by Detlef Warnke, Gabriel M. Filippelli and José-Abel Flores. Deep-Sea Research. Part II: Topical Studies in Oceanography, 54(21-22), p.2350-2366. Publisher: Elsevier, Oxford, International. ISSN: 0967-0645
Note: In English. Based on Publisher-supplied data; illus., incl. geol. sketch maps
Summary: The spatial and temporal distribution of biogenic and lithogenic sediments in the late Quaternary Southern Ocean reflects the zonal character of the Antarctic Circumpolar Current and is basically controlled by glacial dynamics in Antarctica, sea-ice distribution, temperature gradients, wind patterns, and thermohaline ocean circulation. Carbonate patterns in most places reveal a decline in biogenic carbonate preservation during glacial periods, mainly attributed to a reduced influx of North Atlantic Deep Water and increased ocean stratification, which modified deep-water chemistry towards more corrosivity. An important lithological feature of the Southern Ocean is the Circumpolar Opal Belt, which today is situated between the Polar Front and the seasonal sea-ice limit to the south. During the glacial periods the opal belt shifted to the north in response to a wider sea-ice extension that reduced light availability and diatom productivity to the south. Biosiliceous productivity to the north likely was fueled by detrital iron supplied by aeolian dust input and/or hemipelagic processes. Lithogenic fluxes generally increased during the glacial periods. Provenance studies on the origin and dispersal of detrital materials suggest combined effects of low sea-level stands, increased glaciogenic input, and enhanced current transport to have caused elevated detrital fluxes. The relative and absolute contribution of aeolian dust is difficult to decipher and awaits further clarification by integrated provenance studies of both marine sediments and more reference materials from the potential terrestrial source areas. Ice-rafted debris (IRD) represents a minor fraction of lithogenic sediments, but can be used to infer both Antarctic ice-sheet dynamics and the fate of both sea-ice and iceberg survival in the distal Southern Ocean. Future work should be concentrated on a better identification of IRD origin in terms of volcaniclastic influences, the distinction of east and west Antarctic sediment sources, and sea-ice versus iceberg transportation. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Antarctic Circumpolar Current; Atlantic Ocean; Cape Basin; Carbonate sediments; Cenozoic; Circumpolar opal belt; Clastic sediments; Debris; Dust; Framework silicates; Glaciation; Ice rafting; Leg 177; Marine environment; Marine sediments; ODP Site 1089; ODP Site 1094; Ocean Drilling Program; Ocean circulation; Opal; Paleoenvironment; Quaternary; Sediments; Silica minerals; Silicates; South Atlantic; Southern Ocean; Upper Quaternary
Coordinates: S405611 S405611 E0095338 E0095338
S531049 S531049 E0050749 E0050749
Record ID: 2010080330
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands