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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 3. (March)

First Page: 554

Last Page: 554

Title: Deep-Sea Drilling in Antarctic--Late Tertiary Paleoclimatic History: ABSTRACT

Author(s): Sherwood W. Wise

Article Type: Meeting abstract


Bold efforts by Glomar Challenger to drill in little explored regions of the southern ocean and its environs have considerably advanced knowledge of the earth's paleoclimatic history despite notable logistic problems encountered in working at high latitudes. Of special interest has been the discovery of evidence for the initiation of Southern Hemisphere glaciation during the Oligocene (DSDP Site 270) and the documentation of a particularly severe late Miocene glaciation of Antarctica which may have exceeded all others in intensity. Paleontologic evidence for reduced sea levels and sea temperatures associated with late Miocene glaciation was early noted among foram assemblages from New Zealand, and subsequently confirmed by oxygen isotope analysis (DSDP Site 284). Closer t the continent, late Miocene deep-sea sediments are characterized by strong bottom-current winnowing and multiple hiatuses; contained microfossils are highly fragmented and of low diversity (DSDP Sites 266 and 274). Farther away on the Falkland Plateau, the upper Miocene section is more complete but separated from the overlying Pliocene by a marked disconformity produced by a climatically intensified Antarctic Circumpolar Current (DSDP Site 329), whereas in an adjacent basin, the unconformity was probably produced by accelerated Antarctic Bottom-Water flow (DSDP Site 328).

Equally important to the definition of major climatic events has been the establishment of high-latitude biostratigraphic zonations based on prevalent microfossil groups, particularly diatoms, radiolarians, and silicoflagellates. Keyed into paleomagnetics and the less well-represented calcareous microfossil zones, these new high-latitude biostratigraphies set the stage for future exploration in this area.

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Copyright 1997 American Association of Petroleum Geologists