Simple-shear conjugate rift margins of the Argentine Precordillera and the Ouachita embayment of Laurentia

Abstract

Research Article| July 01, 1999 Simple-shear conjugate rift margins of the Argentine Precordillera and the Ouachita embayment of Laurentia William A. Thomas; William A. Thomas 1Department of Geological Sciences, University of Kentucky, Lexington, Kentucky 40506-0053 Search for other works by this author on: GSW Google Scholar Ricardo A. Astini Ricardo A. Astini 2Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas, y Naturales, Universidad Nacional de Córdoba, Avenida Vélez Sársfield 299 C.C. 395, 5000 Córdoba, Argentina Search for other works by this author on: GSW Google Scholar GSA Bulletin (1999) 111 (7): 1069–1079. https://doi.org/10.1130/0016-7606(1999)111<1069:SSCRMO>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation William A. Thomas, Ricardo A. Astini; Simple-shear conjugate rift margins of the Argentine Precordillera and the Ouachita embayment of Laurentia. GSA Bulletin 1999;; 111 (7): 1069–1079. doi: https://doi.org/10.1130/0016-7606(1999)111<1069:SSCRMO>2.3.CO;2 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 Argentine Precordillera was rifted from the Ouachita embayment of Laurentia during Cambrian time. The Ouachita rifted margin along the Texas promontory of Laurentia exhibits a narrow zone of transitional crust, a lack of synrift rocks, and a thin passive-margin succession, indicating slow and limited postrift subsidence. In contrast, data from the western margin of the Precordillera suggest more extensive synrift sediment accumulations and document a thick passive-margin succession, indicating more rapid and relatively greater postrift subsidence than along the Ouachita margin of Laurentia. Passive-margin deposition began in latest Early Cambrian time around the Precordillera, but it did not begin before latest Middle Cambrian time around the Ouachita embayment. The contrasts in structure and stratigraphy are best explained by an asymmetric rift system in the context of simple-shear, low-angle–detachment models for continental rifting. Differences in subsidence rates and inferred crustal structure suggest that the rifted margin of the Ouachita embayment represents an upper-plate configuration, whereas the conjugate margin on the western Precordillera represents a lower-plate configuration. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.