16 Tectonics of the U.S. Cordillera, SWEAT Connection and Beyond I: A Session in Honor of Eldridge Moores
Friday, 29 April 2005
1:15 PM - 5:20 PM
SWEATING IT OUT IN ANTARCTICA, WITH ALL DUE RESPECT TO ELDRIDGE MOORES
Paper number: 16-5
Program: SYMPOSIA SESSIONS
Time: 2:20 PM – 2:40 PM
Authors
Abstract
In recent years additions and refinements have been made to the long-held, general model of the development of the Ross orogen. It is now recognized that a major discontinuity in the trends of the orogen occurs at Byrd Glacier. To the north in Victoria Land, mounting evidence suggests all of the metasedimentary and metavolcanic sequences are Neoproterozoic, while to the south from the central Transantarctic Mtns to the Pensacola Mtns the majority of the sequences are Early-Middle Cambrian. Detrital zircon data from this region have shown that much of the sedimentation previously assigned to Neoproterozoic is Cambrian. A model to be developed is that of a ribbon continent, >1,000 km long, colliding with the Antarctic margin to the south of Byrd Glacier in the latest Neoproterozoic-early Early Cambrian. New detrital zircon data from Victoria Land show a spike at 2.2-2.3 Ga. The one location along the west side of Laurentia where such a provenance is found is the Peace River arch in B. C. Alternatively, rocks of this interval are widespread throughout South America and Africa, suggesting counterparts to a dangling Antarctica.