Late Oligocene and early Miocene glacimarine sedimentation in the SW Ross Sea, Antarctica; the record from offshore drilling

Author(s): Hambrey, Michael J.; Barrett, Peter J.; Powell, Ross D.
Author Affiliation(s): Primary:
University of Wales, Centre for Glaciology, Aberystwyth, United Kingdom
Other:
Victoria University of Wellington, New Zealand
Northern Illinois University, United States
Volume Title: Glacier-influenced sedimentation on high-latitude continental margins
Volume Author(s): Dowdeswell, Julian A., editor; Ó Cofaigh, Colm
Source: Glacier-influenced sedimentation on high-latitude continental margins, edited by Julian A. Dowdeswell and Colm Ó Cofaigh. Geological Society Special Publications, Vol.203, p.105-128. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719 CODEN: GSLSBW
Note: In English. 77 refs.; illus., incl. 1 plate, 2 tables, sketch maps
Summary: Recent offshore drilling in the SW Ross Sea has recovered three cores with a cumulative thickness of 1500 m of Oligocene-early Miocene strata. Together with data from earlier drilling, notably from the CIROS-1 drillhole 70 km to the south (702 m of core), the cores record shallow marine glacigenic sedimentation at the margin of a rift basin bordering a mountain range that was breached by outlet glaciers from an ice sheet. This paper focuses on the late Oligocene-early Miocene record, which preserves sedimentary facies that represent warmer glacier ice and climatic conditions than are evident in the Antarctic today. Strata were cored near the South Victoria Land coast, and sedimentary facies include diamictite, conglomerate, breccia, sandstone, silstone, mudstone and rhythmite. Facies associations, combined with seismic stratigraphic data, indicate an alternating proximal and distal marine record of glacigenic sedimentation, including phases of glacier grounding and variable degrees of iceberg rafting. Reworking by gravity-flow processes and near-shore submarine currents is also evident. These facies, together with evidence for periglacial vegetation, provide evidence of a late Oligocene-early Miocene climatic regime resembling that in the high-Arctic today. Thus, the climate was transitional between cool-temperate conditions of early Oligocene and cold-polar conditions of Quaternary time.
Year of Publication: 2002
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Antarctica; Basins; Boreholes; Cenozoic; Cores; Currents; Deep Sea Drilling Project; Deformation; Depositional environment; Drilling; Faults; Glacial environment; Glacial geology; Glacial sedimentation; Glaciation; Glaciers; Glaciomarine sedimentation; Gravity flows; Ice movement; Ice sheets; Lithofacies; Lithostratigraphy; Lower Miocene; Marine sedimentation; Mass movements; Miocene; Models; Neogene; Ocean Drilling Program; Ocean currents; Offshore; Oligocene; Paleoclimatology; Paleoenvironment; Paleogene; Rift zones; Ross Sea; Sedimentary rocks; Sedimentary structures; Sedimentation; Seismic stratigraphy; Sequence stratigraphy; Shallow-water environment; Soft sediment deformation; Southern Ocean; Tertiary; Upper Oligocene; Victoria Land
Coordinates: S780000 S770000 E1670000 E1620000
Record ID: 2003068250
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