Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California?

Research Article| June 01, 2002 Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California? G. Lang Farmer; G. Lang Farmer 1Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80309-0399, USA Search for other works by this author on: GSW Google Scholar Allen F. Glazner; Allen F. Glazner 2Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar Curtis R. Manley Curtis R. Manley 2Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2002) 114 (6): 754–768. https://doi.org/10.1130/0016-7606(2002)114<0754:DLDTLC>2.0.CO;2 Article history received: 15 Nov 2000 rev-recd: 10 Oct 2001 accepted: 03 Dec 2001 first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation G. Lang Farmer, Allen F. Glazner, Curtis R. Manley; Did lithospheric delamination trigger late Cenozoic potassic volcanism in the southern Sierra Nevada, California?. GSA Bulletin 2002;; 114 (6): 754–768. doi: https://doi.org/10.1130/0016-7606(2002)114<0754:DLDTLC>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract New chemical and isotopic data demonstrate that Pliocene volcanic rocks in the Kings and San Joaquin volcanic fields in the central Sierra Nevada, California, are more potassic, trend toward more mafic compositions, and have distinctly lower εNd values than Miocene volcanic rocks found anywhere in the southern half of the mountain range. The Pliocene magmatism apparently tapped a low-εNd (−6 to −8), K-metasomatized mantle not involved in Sierran magmatism at any other time in the Cenozoic. Published isotopic data from upper-mantle xenoliths entrained in Miocene and Pliocene volcanic rocks reveal that the only low-εNd mantle in the lithospheric column beneath the central Sierra prior to the Pliocene magmatism was shallow-level, K-metasomatized, spinel peridotite. Melting at such shallow levels in the mantle lithosphere could have been triggered by delamination of deeper parts of the mantle lithosphere, followed by uplift of the remaining continental lithosphere and its heating by upwelling asthenosphere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.