Cenozoic tectonic history of the South Georgia microcontinent and potential as a barrier to Pacific-Atlantic through flow

Carter, Andrew; Curtis, Mike; Schwanethal, James. 2014 Cenozoic tectonic history of the South Georgia microcontinent and potential as a barrier to Pacific-Atlantic through flow. Geology, 42 (4). 299-302. https://doi.org/10.1130/G35091.1

Before downloading, please read NORA policies.

Preview

Text
Geology-2014-Carter-G35091.1.pdf - Published Version
Available under License Creative Commons Attribution.
Download (1MB) | Preview

Official URL: http://dx.doi.org/10.1130/G35091.1

Abstract/Summary

Cenozoic opening of the central Scotia Sea involved the tectonic translation of crustal blocks to form the North Scotia Ridge, which today is a major topographic constriction to the flow of the deep Antarctic Circumpolar Current that keeps Antarctica thermally isolated from warmer ocean waters. How this ridge developed and whether it was a topographic barrier in the past are unknown. To address this we investigated the Cenozoic history of the South Georgia microcontinental block, the exposed part of the ridge. Detrital zircon U-Pb geochronology data confirm that the Cretaceous succession of turbidites exposed on South Georgia was stratigraphically connected to the Rocas Verdes backarc basin, part of the South America plate. Apatite thermochronometry results show that South Georgia had remained connected to South America until ca. 45–40 Ma; both record a distinct rapid cooling event at that time. Subsequent separation from South America was accompanied by kilometer-scale reburial until inversion ca. 10 Ma, coeval with the cessation of spreading at the West Scotia Ridge and collision between the South Georgia block and the Northeast Georgia Rise. Our results show that the South Georgia microcontinental block could not have been an emergent feature from ca. 40 Ma until 10 Ma.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1130/G35091.1
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Environmental Change and Evolution
ISSN:	0091-7613
Date made live:	19 Feb 2014 14:57 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/504940

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1130/G35091.1

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Environmental Change and Evolution

ISSN:

0091-7613

Date made live:

19 Feb 2014 14:57 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/504940