Abstract
This study uses bulk X-ray diffraction (XRD), heavy mineral analysis and analysis of detrital modes of the Sirius Group and related Upper Cenozoic deposits to evaluate their provenance. The data suggest that deposition of the Sirius Group occurred as a result of long-term glacial denudation of the Transantarctic Mountains. Such a conclusion is in contrast with the traditional view of deposition on a pre-existing high relief glacial topography during one relatively short-term phase of glacial expansion by the East Antarctic Ice Sheet. Two petrofacies are distinguished, which have different geomorphological settings and paleo-ice flow directions. One petrofacies includes much material from the higher elevated sedimentary sequences of the Transantarctic Mountains and represents overriding of the mountains and deposition of part of the Sirius Group during of after the late Oligocene to early Miocene. The second petrofacies is characterized by a large input from crystalline basement sources and represents active erosion and deposition in glacial troughs during the Neogene. The second petrofacies of the Sirius Group shows similarities to the record from Dry Valley Drilling Project core 11 (DVDP-11), which indicates that East Antarctic ice was last flowing through the Dry Valleys in the late Miocene to early Pliocene.
Original language | English |
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Pages (from-to) | 263-290 |
Number of pages | 28 |
Journal | Sedimentary Geology |
Volume | 144 |
Issue number | 3-4 |
DOIs | |
State | Published - 2001 |
Keywords
- Cenozoic
- East Antarctica
- Glaciation
- Heavy mineral analysis
- Provenance
- Sirius Group
- X-ray diffraction analysis