Last Remnants of Cenozoic Vegetation and Organic-Walled Phytoplankton in the Antarctic Peninsula's Icehouse World
© 2011 by the American Geophysical Union. A late Oligocene, a middle Miocene, and two adjacent Pliocene sections were sampled off the coast of the Antarctic Peninsula in shelf sediments on the Joinville Plateau, Weddell Sea. Drilling was conducted from the research vessel icebreaker Nathaniel B. Pal...
| Main Authors: | , |
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| Format: | Text |
| Language: | unknown |
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LSU Digital Commons
2013
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| Online Access: | https://digitalcommons.lsu.edu/geo_pubs/1055 https://doi.org/10.1029/2010SP000996 |
| Summary: | © 2011 by the American Geophysical Union. A late Oligocene, a middle Miocene, and two adjacent Pliocene sections were sampled off the coast of the Antarctic Peninsula in shelf sediments on the Joinville Plateau, Weddell Sea. Drilling was conducted from the research vessel icebreaker Nathaniel B. Palmer during the 2006 SHALDRIL campaign. The drill holes recovered sediment cores that each span a short interval of time because of extensive sea ice constraints during drilling. Despite this limitation, the palynomorphs extracted from these sediments help constrain the region's past environmental conditions during three periods of the icehouse world and confirm that tundra vegetation persisted in the Antarctic Peninsula up to at least 12.8 Ma. The terrestrial palynological data reflect southern beech and conifer-dominated woodlands and tundra during the Oligocene, with reduction to pockets of tundra with probably stunted beech and podocarp conifers by the middle Miocene. During both the Oligocene and the Miocene, the phytoplankton were dominated by small sea ice-tolerant opportunistic species taking advantage of the migration of most dinoflagellate cysts to more hospitable parts of the ocean. By the Pliocene, only limited pockets of vegetation may have existed. |
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