Geology of the Bowers Supergroup, Central Bowers Mountains, Northern Victoria Land
- Edmund Stump
Published Online: 16 MAR 2013
Copyright 1986 by the American Geophysical Union.
Geological Investigations in Northern Victoria Land
How to Cite
Wodzicki, A. and Robert, R. (1986) Geology of the Bowers Supergroup, Central Bowers Mountains, Northern Victoria Land, in Geological Investigations in Northern Victoria Land (ed E. Stump), American Geophysical Union, Washington, D. C.. doi: 10.1002/9781118664957.ch3
- Published Online: 16 MAR 2013
- Published Print: 1 JAN 1986
Print ISBN: 9780875901978
Online ISBN: 9781118664957
- Geology—Antarctic regions—Victoria Land
The Bowers Supergroup is at least 6.5 km thick and consists of Solidarity, Molar, and Glasgow formations of the Middle Cambrian Sledgers Group; Middle Cambrian to Early Ordovician Mariner Group; and Middle Ordovician Leap Year Group. The Solidarity Formation is at least 0.4 km thick and consists of submarine tholelites. The Molar Formation is up to 2.7 km thick and consists of slope facies turbidites in the southwest and shelf facies sediments in the northeast. Sediment provenance was from coeval Glasgow Formation and a continental landmass northeast of a southwest sloping basin. The Glasgow Formation is up to 2.7 km thick and consists of tholeiitic and calc-alkaline basalts to rhyolites erupted along a magmatic arc probably related to eastward subduction. The Mariner Group is a regressive marine sequence deposited during tectonic quiescence. The Leap Year Group rests unconformably on the Mariner and Sledgers groups and consists of up to 2.5 km of molasse, derived in part from Granite Harbour Intrusives. The Bowers Supergroup was folded about N30°W axes, metamorphosed to prehnite-pumpellyite facies, then tectonically juxtaposed by strike slip faults against Wilson and Robertson Bay terranes. Deposition of the Leap Year Group, folding, metamorphism, and faulting occurred between about 490 and 430 Ma and resulted from a collison between Wilson and Bowers terranes during the Ross Orogeny in northern Victoria Land. Between 420 and 384 Ma, refolding about N60°E axes and normal faulting occurred during the Borchgrevink Event. The three terranes became stitched by the time postorogenic Admiralty Intrusives were emplaced.