U-Pb geochronology and geochemistry of the McCoy Mountains Formation, southeastern California: A Cretaceous retroarc foreland basin

Research Article| January 01, 2004 U-Pb geochronology and geochemistry of the McCoy Mountains Formation, southeastern California: A Cretaceous retroarc foreland basin Andrew P. Barth; Andrew P. Barth 1Department of Geology, Indiana University–Purdue University, Indianapolis, Indiana 46202, USA Search for other works by this author on: GSW Google Scholar Joseph L. Wooden; Joseph L. Wooden 2U.S. Geological Survey, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Carl E. Jacobson; Carl E. Jacobson 3Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011, USA Search for other works by this author on: GSW Google Scholar Kelly Probst Kelly Probst 4Department of Geology, Indiana University–Purdue University, Indianapolis, Indiana 46202, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Andrew P. Barth 1Department of Geology, Indiana University–Purdue University, Indianapolis, Indiana 46202, USA Joseph L. Wooden 2U.S. Geological Survey, Menlo Park, California 94025, USA Carl E. Jacobson 3Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011, USA Kelly Probst 4Department of Geology, Indiana University–Purdue University, Indianapolis, Indiana 46202, USA Publisher: Geological Society of America Received: 06 Nov 2002 Revision Received: 23 May 2003 Accepted: 24 Jun 2003 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2004) 116 (1-2): 142–153. https://doi.org/10.1130/B25288.1 Article history Received: 06 Nov 2002 Revision Received: 23 May 2003 Accepted: 24 Jun 2003 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Andrew P. Barth, Joseph L. Wooden, Carl E. Jacobson, Kelly Probst; U-Pb geochronology and geochemistry of the McCoy Mountains Formation, southeastern California: A Cretaceous retroarc foreland basin. GSA Bulletin 2004;; 116 (1-2): 142–153. doi: https://doi.org/10.1130/B25288.1 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 timing of deposition of fluvial sediments now forming the >7-km-thick McCoy Mountains Formation is one of the key uncertainties in reconstructing the Mesozoic paleogeography of southern California and western Arizona. Ion-microprobe U-Pb geochronologic data for individual zircons from nine sandstones from the McCoy Mountains type section and six associated igneous rocks provide significant new constraints on the tectonic setting and the timing of deposition within the northwest-trending McCoy basin. U-Pb zircon data from a metavolcanic rock of the underlying Dome Rock sequence in the Palen Mountains confirm that the McCoy Mountains Formation was deposited after regional Middle to Late Jurassic arc magmatism. U-Pb zircon data from a Late Cretaceous granodiorite intruding the formation in the Coxcomb Mountains confirm that the formation was deformed and metamorphosed prior to 73.5 ± 1.3 Ma. Populations of detrital zircons vary systematically with both rock type and stratigraphic height; lithic arkoses predominantly derived from the west have consistently more abundant younger zircons than do litharenite sandstones predominantly derived from the north, and the youngest zircons yield maximum depositional ages that decrease from 116 Ma near the base to 84 Ma near the top of the section. The detrital-zircon data permit a Late Jurassic age for the basal, comparatively quartz-rich sandstone. However, the data further suggest that >90% of the formation was deposited between middle Early and middle Late Cretaceous time. These results are consistent with the hypothesis that most of the McCoy Mountains Formation represents a retroarc foreland basin, deposited behind the active, evolving Cretaceous Cordilleran continental- margin magmatic arc that lay to the west and in the foreland of the actively deforming Cretaceous Maria fold-and-thrust belt. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.