Cenozoic climatic change in Antarctica recorded by volcanic activity and landscape evolution
A long-lasting Cenozoic record (similar to 50 m.y.) of alkaline igneous rocks characterizes northern Victoria Land, Antarctica, Landscape analysis allows distinction between older volcanic and intrusive rocks with well-developed alpine topography sculptured by wet-based glaciers, and younger volcani...
| Main Authors: | , |
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| Other Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
1999
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| Subjects: | |
| Online Access: | http://hdl.handle.net/11568/189463 http://geology.gsapubs.org/content/27/7/617.full.pdf+html?sid=7f27f59c-da83-483e-9852-4a8f4572ba98 |
| Summary: | A long-lasting Cenozoic record (similar to 50 m.y.) of alkaline igneous rocks characterizes northern Victoria Land, Antarctica, Landscape analysis allows distinction between older volcanic and intrusive rocks with well-developed alpine topography sculptured by wet-based glaciers, and younger volcanic cones lacking these features. Many K-Ar and Rb-Sr dates testify that the erosion that formed the alpine landscape ceased between ca, 8.2 and 7.5 Ma, Since ca, 8 Ma, morphological evolution has been driven by cold-based glaciers; warm-based glaciers were no longer active. That this change affected a 300-km-long coastal area suggests a persistent cause of global significance. Glacier dynamics control landscape shaping as a function of ice thickness and temperature, which are driven by climatic conditions. In this view, a significant climatic change occurred in northern Victoria Land between 8.2 and 7.5 Ma. The perfectly preserved serrated alpine ridges, with their delicate spires, testify that no warm-based ice sheets overrode the region after 7.5 Ma and that polar conditions held sway in the Pliocene and Pleistocene Epochs. |
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