Research Article| May 01, 1990 Stratigraphy and provenance of strata along the San Marcos fault, central Coahuila, Mexico JAMES W. McKEE; JAMES W. McKEE 1Department of Geology, University of Wisconsin-Oshkosh, Oshkosh, Wisconsin 54901 Search for other works by this author on: GSW Google Scholar NORRIS W. JONES; NORRIS W. JONES 1Department of Geology, University of Wisconsin-Oshkosh, Oshkosh, Wisconsin 54901 Search for other works by this author on: GSW Google Scholar LEON E. LONG LEON E. LONG 2Department of Geological Sciences, The University of Texas at Austin, Austin, Texas 78713 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1990) 102 (5): 593–614. https://doi.org/10.1130/0016-7606(1990)102<0593:SAPOSA>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 JAMES W. McKEE, NORRIS W. JONES, LEON E. LONG; Stratigraphy and provenance of strata along the San Marcos fault, central Coahuila, Mexico. GSA Bulletin 1990;; 102 (5): 593–614. doi: https://doi.org/10.1130/0016-7606(1990)102<0593:SAPOSA>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 Stratigraphic and petrologic studies, supported by geologic mapping north of the San Marcos fault (central Coahuila), indicate that as much as 3,000 m of coarse Upper Jurassic and Lower Cretaceous detritus was derived from south of the fault. Two coarse Jurassic submarine conglomerate units (Las Palomas and Sierra El Granizo beds of the La Casita Formation) reflect separate episodes of displacement. Younger Jurassic eolianite and marine sandstone (Colorado and Tanque Cuatro Palmas beds of the La Casita Formation) record subsequent (Tithonian) fault inactivity. Neocomian rejuvenation of the fault produced alluvial deposits (San Marcos Formation); finer-grained, paralic or marine strata that are distal and suprajacent, and manifest the same faulting, are the La Mula Formation. Interruption of Neocomian displacement is indicated by a tongue of carbonate (Padilla and Barril Viejo Formations) that divides the San Marcos into upper and lower members.The principal source of this detritus was the wildflysch of the late Paleozoic, arcproximal Las Delicias basin and the plutonic rocks that cut it. Rb-Sr ages on clasts and from outcrops of granitic rocks are Triassic and probably reflect late-stage magmatism within the Las Delicias arc. Although this arc supplied most of the detritus to the Las Delicias basin, Devonian ages on some clasts reveal that an unknown source area lay somewhere nearby during the late part of the Paleozoic Era.The San Marcos fault may have served as part of the system of transform faults that connected sea-floor-spreading ridges of the Atlantic with those of the Pacific. If so, then the Jurassic units record periods of Jurassic activity and inactivity of that system. Neocomian displacment may have been caused by subsequent isostatic adjustment. 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.