Depth and mineralogy of the magma source or pause region for the Carboniferous Liberty Hill pluton, South Carolina

Abstract

Research Article| June 01, 1988 Depth and mineralogy of the magma source or pause region for the Carboniferous Liberty Hill pluton, South Carolina J. Alexander Speer J. Alexander Speer 1Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695-8208 Search for other works by this author on: GSW Google Scholar Author and Article Information J. Alexander Speer 1Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695-8208 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1988) 16 (6): 521–524. https://doi.org/10.1130/0091-7613(1988)016<0521:DAMOTM>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. Alexander Speer; Depth and mineralogy of the magma source or pause region for the Carboniferous Liberty Hill pluton, South Carolina. Geology 1988;; 16 (6): 521–524. doi: https://doi.org/10.1130/0091-7613(1988)016<0521:DAMOTM>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 SocietyGeology Search Advanced Search Abstract Use of Al content geobarometry on clinopyroxene inclusions in plagioclase from the Carboniferous Liberty Hill pluton, South Carolina, yields pressure estimates of 8-10 kbar. Amphibole crystallization pressures are 3.1-4.7 kbar; contact metamorphic pressures are 4.5 kbar. Clinopyroxenes could be early crystallization products from the melt, restite crystals from the source region, xenocrysts from the magma conduit walls, or xenocrysts from a more mafic magma. Compositional uniformity of granitoid clinopyroxenes but dissimilarity with those in contemporaneous gabbroids is evidence against a xenocrystic origin. The deeper depths are interpreted as either the source region or a pausing place important in the crystallization history of the magma during its ascent to the upper crust. Early crystallization assemblage of the granitoid, and possibly the assemblage of the source region, was amphibole + clinopyroxene ± plagioclase-bearing. An amphibolitic lower crustal source is consistent with the Sr and O isotopic and rare-earth-element studies of this and many other similar-age granitoids in the southern Appalachians. 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.