Geological Society of America

T165 Structure and Tectonic Studies, from Outcrop to Supercontinent I: In Honor of Ian Dalziel

Tuesday, 24 September 2019
8:00 AM - 12:00 PM
Room 229A, North Building

RODINIA SUPERCONTINENT CONSTRAINTS FROM THE AREQUIPA TERRANE IN SOUTHERN PERU

Paper number: T165-13
Program: Technical Sessions
Time: 11:00 AM – 11:15 AM

Authors

Eben Blake Hodgin Presenting Author
Harvard University, Cambridge, MA
Francis Macdonald
University of California, Santa Barbara, Santa Barbara, CA
James Crowley
Boise State University, Boise, ID
Justin Newmann
UC Santa Barbara, Santa Barbara, CA
Victor Carlotto
Universidad Nacional de San Antonio Abad del Cusco, Cusco

Abstract

Ian Dalziel pioneered work on the Proterozoic configuration of Laurentia, Amazonia, and Kalahari, forming the core of the supercontinent Rodinia. Here we build off this work with new stratigraphic and geochronological constraints from the Arequipa terrane in southern Peru as a missing link to provide new ties between these cratons. Two Cryogenian diamictite and cap carbonate pairs, the Ediacaran Shuram Isotope Excursion, the Precambrian-Cambrian boundary, and an Early Cambrian fossil assemblage are identified in coastal southern Peru, and are used to provide an age model for basin formation. Basement ages, lithostratigraphy, and the timing of basin formation suggest a Kalahari origin of the Arequipa terrane and a connection with the Pampean Orogeny in northwestern Argentina. We propose that the Arequipa terrane rifted from the Kalahari during the Tonian to Cryogenian, was an isolated carbonate platform during the Ediacaran, and was dextrally translated along the Gondwanan margin during the Cambrian. Evidence for final amalgamation of the Arequipa terrane is recorded by Late Cambrian magmatic and metamorphic ages in the Eastern Cordillera of southern Peru.

Geological Society of America Abstracts with Programs. Vol. 51, No. 5

doi: 10.1130/abs/2019AM-340502

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