2004/01/01 by Staci L. Loewy, Staci Loewy, James N. Connelly +2 · 7 citations
Earth and Planetary Sciences · #Geological and Geochemical Analysis #Geological and Tectonic Studies in Latin America #earthquake and tectonic studies
paper · doi:10.1130/b25226.1
Research Article| January 01, 2004 An orphaned basement block: The Arequipa-Antofalla Basement of the central Andean margin of South America Staci L. Loewy; Staci L. Loewy 1Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar James N. Connelly; James N. Connelly 1Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Ian W.D. Dalziel Ian W.D. Dalziel 2Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA and Institute for Geophysics, The University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Staci L. Loewy 1Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA James N. Connelly 1Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA Ian W.D. Dalziel 2Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78712, USA and Institute for Geophysics, The University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759, USA Publisher: Geological Society of America Received: 01 Aug 2002 Revision Received: 27 Jun 2003 Accepted: 06 Jul 2003 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2004) 116 (1-2): 171–187. https://doi.org/10.1130/B25226.1 Article history Received: 01 Aug 2002 Revision Received: 27 Jun 2003 Accepted: 06 Jul 2003 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Staci L. Loewy, James N. Connelly, Ian W.D. Dalziel; An orphaned basement block: The Arequipa-Antofalla Basement of the central Andean margin of South America. GSA Bulletin 2004;; 116 (1-2): 171–187. doi: https://doi.org/10.1130/B25226.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The Arequipa-Antofalla Basement, a Proterozoic crustal block exposed along the central Andean margin, provides a key to interpreting the pre-Andean history of South America. New U/Pb geochronology and whole-rock Pb and Nd isotope geochemistry from the Arequipa-Antofalla Basement refine the tectonic history and delineate three distinct crustal domains that decrease in age from north to south. The northern domain of southern Peru and western Bolivia contains juvenile Paleoproterozoic 2.02–1.79 Ga intrusions that were metamorphosed at 1.82–1.79 Ga. The Mesoproterozoic central domain in northernmost Chile contains a significant Mesoproterozoic juvenile component that incorporates Paleoproterozoic crust from the northern domain. Rock units from both the northern and central domains were metamorphosed between 1.20 and 0.94 Ga, with coeval magmatism occurring only in the central domain. The southern domain in northern Chile and northwestern Argentina comprises Ordovician rocks, derived from a mix of juvenile material and older crust. Similar Ordovician magmatism (476–440 Ma) also occurred in the northern and central domains followed by metamorphism at ca. 440 Ma.Based on this refined geologic and tec tonic characterization of the Arequipa- Antofalla Basement and comparison with that of Amazonia, we conclude that: (1) the isolated exposures of the Arequipa-Antofalla Basement comprise a single basement block with multiple domains, (2) the Arequipa-Antofalla Basement was not derived from Amazonia, and (3) the Arequipa-Antofalla Basement accreted onto Amazonia during the 1.0 Ga Sunsás Orogeny. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.