Early opening of Drake Passage: regional seismic stratigraphy and paleoceanographic implications
Summary The tectonics and distribution of seismic units of the central and southern Scotia Sea are described based on multichannel seismic profiles and magnetic anomalies. Recently acquired profiles suggest that spreading in the Drake Passage was active prior to 30.9 Ma, although the tectonics of th...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.516.7632 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea057.pdf |
| Summary: | Summary The tectonics and distribution of seismic units of the central and southern Scotia Sea are described based on multichannel seismic profiles and magnetic anomalies. Recently acquired profiles suggest that spreading in the Drake Passage was active prior to 30.9 Ma, although the tectonics of the area suggests that rifting of the margins and shallow gateways existed well before that time. After breakup, the Scotia Sea developed from several spreading centers that produced ocean basins. Five main seismic units are identified in the Cenozoic sedimentary section. The three youngest units exhibit similar seismic facies and are correlated at regional scale. These deposits contain a variety of contourite drifts resulting from the interplay between the northeastward flow of the Weddell Sea Deep Water, the Antarctic Circumpolar Current and the complex bathymetry. The three units were deposited after the Middle Miocene connection between the Scotia Sea and the Weddell Sea was established. |
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