Preliminary results of the Deep Freeze 85 marine geologic and geophysical survey of the Antarctic Peninsula continental shelf and South Orkney Plateau
Seismic profiles from the South Orkney Plateau show a relatively thick (>0.7 seconds), laminated sequence resting on block faulted acoustic basement and deformed strata. This represents the rifting of the plateau from the Antarctic Peninsula and subsequent pelagic sedimentation. A glacial erosional surface and associated glacial trough were identified on the platform, and possible basal till collected in at least one piston core. Seismic lines from the continental shelf north of the South Shetland Plateau show gently folded reflectors that have been truncated by a widespread erosional unconformity and probable moraines situated near the shelf edge. A line across the Bransfield Strait, a modern back-arc basin, shows the structural features of the basin and thick (>1.0 second) laminated sediments within the center of the basin. One of several deep channels which dissect the shelf was surveyed, but the origin of these features remains uncertain. Geophysical data and piston cores were acquired in several of the bays and fjords of the peninsula region. This is the first detailed survey of Antarctic bays and fjords. The preliminary results show striking differences in sedimentation between Antarctic fjords and those of Arctic and Subarctic regions, the most important difference being the limited role of meltwater runoff in the supply of sediment to Antarctic fjords.
- Research Organization:
- Rice Univ., Houston, TX (USA)
- OSTI ID:
- 6676254
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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