Time-transgressive and extension-related basaltic volcanism in southwest Utah and vicinity

Research Article| October 01, 1997 Time-transgressive and extension-related basaltic volcanism in southwest Utah and vicinity Stephen T. Nelson; Stephen T. Nelson 1Woodward-Clyde Federal Services, 1180 Town Center Drive, Las Vegas, Nevada 89134 Search for other works by this author on: GSW Google Scholar David G. Tingey David G. Tingey 2Department of Geology, Brigham Young University, Provo, Utah 84602 Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen T. Nelson 1Woodward-Clyde Federal Services, 1180 Town Center Drive, Las Vegas, Nevada 89134 David G. Tingey 2Department of Geology, Brigham Young University, Provo, Utah 84602 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1997) 109 (10): 1249–1265. https://doi.org/10.1130/0016-7606(1997)109<1249:TTAERB>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 Email Permissions Search Site Citation Stephen T. Nelson, David G. Tingey; Time-transgressive and extension-related basaltic volcanism in southwest Utah and vicinity. GSA Bulletin 1997;; 109 (10): 1249–1265. doi: https://doi.org/10.1130/0016-7606(1997)109<1249:TTAERB>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 Late Cenozoic (<15 Ma) basaltic rocks define two temporally and spatially distinct magmatic belts in southwest Utah that are located in the Basin and Range Province, the transition zone, and into the Colorado Plateau interior. The belts share certain time-space-composition characteristics and are dissimilar in others. The north-south Black Rock–Grand Canyon belt (generally 2.5–0 Ma) exhibits no province-wide time-space patterns, but shows distinct space-composition variations involving both lithospheric and asthenospheric magma sources. Magmatism is inferred to have occurred in response to east-west extension, and the composition of the basalts is compatible with maximum thinning and extension by pure shear of the mantle lithosphere occurs near the transition zone.In contrast, the Pahranagat–San Rafael belt (15–3.5 Ma) exhibits a northeastward time-space progression of magmatism. The magmatic migration vector is similar to the Yellowstone trend, suggesting the ultimate influence of a fixed heat or magma source in the asthenosphere, although the basalts record apparent lithospheric signatures. Basalts from this belt are progressively more isotopically primitive and more alkaline into the Colorado Plateau. These chemical variations can be interpreted as a change in the mantle source, depth or degree of partial melting, or decreasing crustal contamination to the northeast. 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.