Granite genesis and mafic-felsic magma interaction in the lower crust

Abstract

Research Article| December 01, 2010 Granite genesis and mafic-felsic magma interaction in the lower crust G.C. Koteas; G.C. Koteas 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA Search for other works by this author on: GSW Google Scholar M.L. Williams; M.L. Williams 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA Search for other works by this author on: GSW Google Scholar S.J. Seaman; S.J. Seaman 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA Search for other works by this author on: GSW Google Scholar G. Dumond G. Dumond 2Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA Search for other works by this author on: GSW Google Scholar Author and Article Information G.C. Koteas 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA M.L. Williams 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA S.J. Seaman 1Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA G. Dumond 2Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA Publisher: Geological Society of America Received: 11 Jan 2010 Revision Received: 15 Jun 2010 Accepted: 01 Jul 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (12): 1067–1070. https://doi.org/10.1130/G31017.1 Article history Received: 11 Jan 2010 Revision Received: 15 Jun 2010 Accepted: 01 Jul 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation G.C. Koteas, M.L. Williams, S.J. Seaman, G. Dumond; Granite genesis and mafic-felsic magma interaction in the lower crust. Geology 2010;; 38 (12): 1067–1070. doi: https://doi.org/10.1130/G31017.1 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 SocietyGeology Search Advanced Search Abstract Field observations from an exposed section of deep continental crust, the Athabasca granulite terrane (AGT), Saskatchewan, Canada, provide a view of granite genesis and a mechanism for deep-seated contamination of felsic and mafic magmas. The 1.9 Ga Chipman mafic dike swarm was emplaced into the Chipman Tonalite (ca. 3.3 Ga) and the megacrystic Fehr granite (ca. 2.6 Ga) at a crustal depth of ∼40 km. The Fehr granite shows evidence for extensive partial melting and generation of granitic leucosome. Mafic dikes and granitic leucosome display magma mingling and mixing textures similar to those widely described from shallow crustal exposures. The AGT provides a view of a dynamic, heterogeneous, and locally fertile deep crust. Mantle-derived mafic magma promotes extensive partial melting of fertile granitoids, which in turn filter and entrap later mafic dikes and sills. The result is almost inevitable mingling and hybridization (i.e., contamination) of mafic and felsic end members. This interaction of magmas in the deep crustal environment may account for the isotopic and compositional signatures of igneous rocks at shallower crustal levels that typically record contamination of crustal melts by mantle material and vice versa. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.