Pleistocene uplift and palaeoenvironments of Macquarie Island:evidence from palaeobeaches and sedimentary deposits
Macquarie Island (54°30′S, 159°00′E) is an emergent part of the Macquarie Ridge Complex. A number of landforms, including palaeobeaches now above sea level were formed by marine erosion during uplift of the island. Two lines of evidence are considered: direct dating of raised beaches by the thermolu...
| Main Authors: | , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
1996
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| Subjects: | |
| Online Access: | https://researchers.mq.edu.au/en/publications/06d1efa1-ec15-4aca-965a-56cac25d25f9 http://www.scopus.com/inward/record.url?scp=0030427819&partnerID=8YFLogxK https://eprints.utas.edu.au/14429/ |
| Summary: | Macquarie Island (54°30′S, 159°00′E) is an emergent part of the Macquarie Ridge Complex. A number of landforms, including palaeobeaches now above sea level were formed by marine erosion during uplift of the island. Two lines of evidence are considered: direct dating of raised beaches by the thermoluminescence method, and cross-matching of the world sea-level sequence with the altitudinal sequence of beaches. An average rate of uplift for the island of 0.8 mma -1 is calculated. At this rate, 4000 m of Macquarie Ridge uplift would have taken about five million years and the top of the island may first have emerged some 700 to 600 ka. During the six Pleistocene glacial-interglacial cycles since then, there has been periglacial rather than glacial activity on cold uplands, but conditions suitable for vegetation of the present type persisted close to sea level. |
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