Stratigraphy and Petrology of Permian and Triassic Fluvial Deposits in Northern Victoria Land, Antarctica
- Edmund Stump
Published Online: 16 MAR 2013
Copyright 1986 by the American Geophysical Union.
Geological Investigations in Northern Victoria Land
How to Cite
Collinson, J. W., Pennington, D. C. and Kemp, N. R. (1986) Stratigraphy and Petrology of Permian and Triassic Fluvial Deposits in Northern Victoria Land, Antarctica, in Geological Investigations in Northern Victoria Land (ed E. Stump), American Geophysical Union, Washington, D. C.. doi: 10.1002/9781118664957.ch9
- Published Online: 16 MAR 2013
- Published Print: 1 JAN 1986
Print ISBN: 9780875901978
Online ISBN: 9781118664957
- Geology—Antarctic regions—Victoria Land
The Beacon Supergroup in northern Victoria Land is represented by three formations, an unnamed Upper Carboniferous-Lower Permian diamictite, the Takrouna Formation of Permian age, and an Upper Triassic unit, which is herein named the Section Peak Formation. The diamictite unit occurs sporadically in the Lanterman Range, the Morozumi Range, and the Neall Massif area. A maximum thickness of 350 m has been reported from the Lanterman Range, where the diamictite is demonstrably of glacial origin. No definite glacial features were observed in the diamictite at other localities. The Takrouna Formation, a predominantly sandstone unit with subsidiary noncarbonaceous and carbonaceous mudstone, occurs in the lower Rennick Glacier region in the Freyberg Mountains, Lanterman Range, Morozumi Range, and Helliwell Hills. The maximum known thickness is about 300 m. The Section Peak Formation, which is dominated by coarse sandstone, occurs in the upper Rennick Glacier region along the margin of the polar plateau. The Section Peak Formation is less than 100 m thick in the study area, although it may be considerably thicker to the south at Timber Peak on the Priestley Glacier. Both Permo-Carboniferous and Triassic units rest directly on lower Paleozoic basement rocks in their respective areas of outcrop. Permian and Triassic sandstones are similar in appearance because they were both deposited by sandy braided stream systems, but they are compositionally distinct. Takrouna sandstones contain quartz, feldspar, and a minor lithic component derived from local basement rocks, Section Peak sandstones contain quartz, feldspar, and volcanic rock fragments that were derived from a calc-alkaline volcanic terrane. Diamictites and the Takrouna Formation were deposited in the Rennick basin, a troughlike depression that coincides with the modern graben now occupied by the Rennick Glacier. Section Peak deposition began only after the Rennick basin had been filled by sediments by the Late Triassic.