A Little Piece of Texas in Antarctica? Geographic and Environmental Implications

Join Zoom Meeting
Join this presentation In-Person: BEG Building 130, Main Conference Room 1.202 Or Via Zoom

Meeting ID: 932 0137 7630
Passcode: 013011

Presenter

lan W.D. Dalziel, Ph.D.
Senior Research Scientist
Institute for Geophysics
Professor of Earth and Planetary Sciences
Jackson School of Geosciences
The University of Texas at Austin

Description

The Ellsworth Mountains form part of one of four crustal blocks that comprise West Antarctica. Restoration of the late Paleozoic-early Mesozoic Gondwanide fold belt places the block on the ‘outboard’ Pacific side of the Coats Land crustal block of the East Antarctic craton, a likely former fragment of Laurentia. The Precambrian basement of the Ellsworth-Whitmore mountains block is indistinguishable from that of south-central and south-western Texas and the overlying Neoproterozoic-Cambrian strata on both continents reflect two-stage continental rifting and late Cambrian continental separation. The detrital zircon population of those strata of the Ellsworths is virtually identical to that of Cambrian sandstones of Texas and therefore of likely Laurentian provenance. The Ellsworth-Whitmore Mountains crustal block of West Antarctica is hence also of likely Laurentian derivation, originally part of a proposed former ‘Ellsworth-Coats Land promontory’ separated from its parent craton during the late Cambrian and subsequently overlain by the Gondwana supercontinental sedimentary cover. This has global paleogeographic and paleoenvironmental implications for the hypothetical Pannotia supercontinent,  Cambrian global environment and the initial radiation of multicellular life.

(Dalziel, I.W.D., Loewy, S.L., Dickerson, P.W., and Malone, J.R., Geosphere, in review)