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Antipodean fugitive terranes in southern Laurentia; how Proterozoic Australia built the American West

George M. Gibson and D. C. Champion
Antipodean fugitive terranes in southern Laurentia; how Proterozoic Australia built the American West
Lithosphere (August 2019) 11 (4): 551-559

Abstract

Paleoproterozoic arc and backarc assemblages accreted to the south Laurentian margin between 1800 Ma and 1600 Ma, and previously thought to be indigenous to North America, more likely represent fragments of a dismembered marginal sea developed outboard of the formerly opposing Australian-Antarctic plate. Fugitive elements of this arc-backarc system in North America share a common geological record with their left-behind Australia-Antarctic counterparts, including discrete peaks in tectonic and/or magmatic activity at 1780 Ma, 1760 Ma, 1740 Ma, 1710-1705 Ma, 1690-1670 Ma, 1650 Ma, and 1620 Ma. Subduction rollback, ocean basin closure, and the arrival of Laurentia at the Australian-Antarctic convergent margin first led to arc-continent collision at 1650-1640 Ma and then continent-continent collision by 1620 Ma as the last vestiges of the backarc basin collapsed. Collision induced obduction and transfer of the arc and more outboard parts of the Australian-Antarctic backarc basin onto the Laurentian margin, where they remained following later breakup of the Neoproterozoic Rodinia supercontinent. North American felsic rocks generally yield Nd depleted mantle model ages consistent with arc and backarc assemblages built on early Paleoproterozoic Australian crust as opposed to older Archean basement making up the now underlying Wyoming and Superior cratons.


ISSN: 1941-8264
EISSN: 1947-4253
Serial Title: Lithosphere
Serial Volume: 11
Serial Issue: 4
Title: Antipodean fugitive terranes in southern Laurentia; how Proterozoic Australia built the American West
Affiliation: Australian National University, Research School of Earth Sciences, Canberra, A.C.T., Australia
Pages: 551-559
Published: 20190801
Text Language: English
Publisher: Geological Society of America, Boulder, CO, United States
References: 79
Accession Number: 2019-065672
Categories: Solid-earth geophysics
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus.
N42°00'00" - N84°00'00", W141°00'00" - W52°00'00"
S90°00'00" - S61°00'00", W180°00'00" - E180°00'00"
Secondary Affiliation: Geoscience Australia, AUS, Australia
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 2019
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