GSA 2020 Connects Online

Paper No. 198-2
Presentation Time: 1:45 PM

CONSTRAINTS FROM THE AREQUIPA TERRANE ON THE NEOPROTEROZOIC-CAMBRIAN RIFT HISTORY OF LAURENTIA


HODGIN, Eben B., Earth and Planetary Sciences, University of California Berkeley, Berkeley, CA 94720; Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138, MACDONALD, Francis A., Earth Science, University of California, Santa Barbara, CA 93106-9630, CROWLEY, James L., Department of Geosciences, Boise State University, Boise, ID 83725, BUATOIS, Luis A., Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada, CARLOTTO, Victor, Universidad Nacional de San Antonio Abad del Cusco, Avenida de la Cultura, 733, Cusco, 921, Peru and HANSON, Richard E., Department of Geology, Texas Christian University, Fort Worth, TX 76129

As a commonly proposed missing link between eastern Laurentia and western Amazonia, the Arequipa Terrane (Central Andes, western South America) can be used to test the configuration of the supercontinent Rodinia and the timing of its breakup. The tectonic history of the Arequipa Terrane is captured in a >4 km thick Cryogenian to early Cambrian succession on its western margin containing two Cryogenian diamictite and cap carbonate pairs, an Ediacaran carbonate-dominated passive margin developed across a west-facing hinge zone, and overlain by a late Ediacaran to early Cambrian foreland basin. The lithostratigraphy, timing of basin formation events, and provenance of the succession suggest rift-related linkages between the Kalahari craton and southeastern Laurentia. Thus, we propose that the Arequipa Terrane shared successful Tonian-Cryogenian rifted margins with Kalahari and southeastern Laurentia, was an isolated terrane in the Ediacaran, and collided with southwestern Amazonia in the late Ediacaran to early Cambrian Pampean Orogeny. The tectonic history of the Arequipa Terrane is consistent with Tonian-Cryogenian breakup of Rodinia, fails to support a late Ediacaran to early Cambrian rift-related linkage to southern or eastern Laurentia, and does not support the existence of the supercontinent Pannotia.