Interglacial collapse of Crary Trough-mouth fan, Weddell Sea, Antarctica; implications for Antarctic glacial history

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doi: 10.2110/jsr.69.1276
Author(s): Bart, Philip J.; De Batist, Marc; Jokat, Wilfried
Author Affiliation(s): Primary:
Louisiana State University, Department of Geology and Geophysics, Baton Rouge, LA, United States
Other:
University of Gent, Belgium
Alfred Wegener Institute for Polar and Marine Research, Federal Republic of Germany
Volume Title: Journal of Sedimentary Research
Source: Journal of Sedimentary Research, 69(6), p.1276-1289. Publisher: Society of Economic Paleontologists and Mineralogists, Tulsa, OK, United States. ISSN: 1527-1404
Note: In English. 69 refs.; illus., incl. sketch maps
Summary: In this study, we investigate the stratigraphy of a trough-mouth fan in the Weddell Sea to determine possible relationships between basin-floor stratigraphy and glaciation on Antarctica. Seismic data from the basin floor show a deep, broad, and elongate erosional channel filled by thick chaotic-facies deposits, basin-floor fans, and channel-levee deposits. From seismic-stratigraphy analysis of basin-floor stratigraphy, we infer that this channel formed by large-volume mass wasting sourced from poorly sorted glacial sediments from Crary Trough-Mouth Fan and Dronning Maud Land slopes. Correlation to ODP Leg 113 Site 693 suggests that the mass wasting of the slopes occurred in the early Pliocene. We surmise that collapse occurred during an early Pliocene interglacial and was related to major drawdown of the antarctic ice volume. Collapse was probably triggered by rebound and relative sea-level fall, a mathematically predicted geoidal effect related to antarctic ice-volume reduction. The record of this major ice-volume reduction is not manifest in the trough-mouth fan but rather is manifest in the basin-floor stratigraphy as a major backfilled erosional channel, which extends far beyond the trough-mouth fan.
Year of Publication: 1999
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Antarctic Ocean; Cenozoic; Collapse structures; Crary Trough; Depositional environment; Glacial environment; Glaciomarine environment; Interglacial environment; Lithostratigraphy; Lower Pliocene; Marine environment; Marine sediments; Neogene; Pliocene; Sediments; Seismic stratigraphy; Southern Ocean; Submarine fans; Tertiary; Weddell Sea
Coordinates: S700000 S700000 W0400000 W0400000
Record ID: 2000002585
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by SEPM (Society for Sedimentary Geology), Tulsa, OK, United States