Late Precambrian Chuar Group, Grand Canyon, Arizona

Abstract

Research Article| April 01, 1973 Late Precambrian Chuar Group, Grand Canyon, Arizona TREVOR D. FORD; TREVOR D. FORD 1Department of Geology, University of Leicester, Leicester, England Search for other works by this author on: GSW Google Scholar WILLIAM J. BREED WILLIAM J. BREED 2Museum of Northern Arizona, Flagstaff, Arizona 86001 Search for other works by this author on: GSW Google Scholar Author and Article Information TREVOR D. FORD 1Department of Geology, University of Leicester, Leicester, England WILLIAM J. BREED 2Museum of Northern Arizona, Flagstaff, Arizona 86001 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1973) 84 (4): 1243–1260. https://doi.org/10.1130/0016-7606(1973)84<1243:LPCGGC>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation TREVOR D. FORD, WILLIAM J. BREED; Late Precambrian Chuar Group, Grand Canyon, Arizona. GSA Bulletin 1973;; 84 (4): 1243–1260. doi: https://doi.org/10.1130/0016-7606(1973)84<1243:LPCGGC>2.0.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 Chuar Group is exposed in tributary canyons to the Colorado River over an area some 15 mi (24 km) long and 4 mi (6 km) wide. The rocks are faulted against Paleozoic rocks by the Butte fault on the east, and unconformably overlain by Paleozoic rocks to the west. The group is 6,610 ft (2,013 m) thick and has been divided into three formations and seven members. The lower two formations, Galeros (below) and Kwagunt (above) are predominantly argillaceous with subordinate thin limestone beds, while the highest, Sixty Mile Formation, is mostly coarse breccia. Stromatolites are present at three horizons, one of them biohermal. The form-genera Inzeria, Baicalia, and Boxonia indicate an upper Riphean age. The mega-planktonic fossil Chuaria occurs near the top of the Kwagunt Formation. The Chuar rocks are probably younger than any other Precambrian rocks in Arizona. They may be contemporary with rocks below the Cambrian in eastern California, and with the Windermere Formation of the northern Cordillera. 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.