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Multiphase development of the Atacama Planation Surface recorded by cosmogenic 3He exposure ages: Implications for uplift and Cenozoic climate change in western South America

2009; Geological Society of America; Volume: 37; Issue: 1 Linguagem: Inglês

10.1130/g25437a.1

1943-2682

Laura Evenstar, Adrian J. Hartley, Finlay M. Stuart, Anne E. Mather, C. M. Rice, Guillermo Chong,

Geological and Tectonic Studies in Latin America

Research Article| January 01, 2009 Multiphase development of the Atacama Planation Surface recorded by cosmogenic 3He exposure ages: Implications for uplift and Cenozoic climate change in western South America Laura A. Evenstar; Laura A. Evenstar 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Search for other works by this author on: GSW Google Scholar Adrian J. Hartley; Adrian J. Hartley 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Search for other works by this author on: GSW Google Scholar Finlay M. Stuart; Finlay M. Stuart 2Isotope Geosciences Unit, Scottish Universities Environmental Research Centre, East Kilbride G75 0QF, UK Search for other works by this author on: GSW Google Scholar Anne E. Mather; Anne E. Mather 3Department of Geographical Sciences, University of Plymouth, Plymouth, Devon PL4 8AA, UK Search for other works by this author on: GSW Google Scholar Clive M. Rice; Clive M. Rice 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Search for other works by this author on: GSW Google Scholar Guillermo Chong Guillermo Chong 4Departamento de Ciencias Geológicas, Universidad Católica del Norte, Avenida Angamos 0610, Casilla 1280 Antofagasta, Chile Search for other works by this author on: GSW Google Scholar Author and Article Information Laura A. Evenstar 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Adrian J. Hartley 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Finlay M. Stuart 2Isotope Geosciences Unit, Scottish Universities Environmental Research Centre, East Kilbride G75 0QF, UK Anne E. Mather 3Department of Geographical Sciences, University of Plymouth, Plymouth, Devon PL4 8AA, UK Clive M. Rice 1Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, UK Guillermo Chong 4Departamento de Ciencias Geológicas, Universidad Católica del Norte, Avenida Angamos 0610, Casilla 1280 Antofagasta, Chile Publisher: Geological Society of America Received: 29 Feb 2008 Revision Received: 05 Sep 2008 Accepted: 09 Sep 2008 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (1): 27–30. https://doi.org/10.1130/G25437A.1 Article history Received: 29 Feb 2008 Revision Received: 05 Sep 2008 Accepted: 09 Sep 2008 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Laura A. Evenstar, Adrian J. Hartley, Finlay M. Stuart, Anne E. Mather, Clive M. Rice, Guillermo Chong; Multiphase development of the Atacama Planation Surface recorded by cosmogenic 3He exposure ages: Implications for uplift and Cenozoic climate change in western South America. Geology 2009;; 37 (1): 27–30. doi: https://doi.org/10.1130/G25437A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The Atacama Planation Surface is an extensive west-dipping surface developed between 16°S and 27°S along the Pacific margin of South America. It is considered to have formed between 16 and 7.5 Ma and to have important chronostratigraphic significance. Here we present new cosmogenic 3He exposure dates of boulders on the planation surface using pyroxene and amphibole. Exposure ages display good within- and between-site consistency and range from 22 to 1.2 Ma, with ages of ca. 14.6, 7, and 3 Ma recurring at more than one site on the planation surface. The 14.6 Ma peak records the cessation of the main period of planation surface development, but, contrary to popular opinion, the younger ages reflect subsequent modification of the planation surface by alluvial activity. Comparison with other climate proxies for western South America suggests that since 14.6 Ma, a predominantly hyperarid climate, interspersed with short-lived phases of more intense runoff driven by global climate change, has prevailed. The longevity and composite nature of the Atacama Planation Surface suggest that regionally extensive planation surfaces may have a multiphase history, are unlikely to have any chronostratigraphic significance, and cannot be used to reconstruct uplift histories. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.