Protolith provenance and thermotectonic history of metamorphic rocks in eastern Jamaica: Evolution of a transform plate boundary

Abstract

Research Article| March 01, 2014 Protolith provenance and thermotectonic history of metamorphic rocks in eastern Jamaica: Evolution of a transform plate boundary David P. West, Jr.; David P. West, Jr. † 1Department of Geology, Middlebury College, Middlebury, Vermont 05753, USA †E-mail: dwest@middlebury.edu Search for other works by this author on: GSW Google Scholar Richard N. Abbott, Jr.; Richard N. Abbott, Jr. 2Department of Geology, Appalachian State University, Boone, North Carolina 28608, USA Search for other works by this author on: GSW Google Scholar Betsy R. Bandy; Betsy R. Bandy 3Ministry of Science, Technology, Energy and Mining, Kingston, Jamaica Search for other works by this author on: GSW Google Scholar Michael J. Kunk Michael J. Kunk 4U.S. Geological Survey, MS 926 National Center, Reston, Virginia 20192, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2014) 126 (3-4): 600–614. https://doi.org/10.1130/B30704.1 Article history received: 30 Mar 2012 rev-recd: 17 Sep 2013 accepted: 11 Oct 2013 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation David P. West, Richard N. Abbott, Betsy R. Bandy, Michael J. Kunk; Protolith provenance and thermotectonic history of metamorphic rocks in eastern Jamaica: Evolution of a transform plate boundary. GSA Bulletin 2014;; 126 (3-4): 600–614. doi: https://doi.org/10.1130/B30704.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Two fault-bounded sequences of metamorphic rocks are exposed in the Blue Mountains of eastern Jamaica. Westphalia Schist is dominated by amphibolite facies hornblende schist and mica schist. Mt. Hibernia Schist is dominated by blueschist-greenschist facies metabasalts. New whole-rock geochemistry and 40Ar/39Ar ages clarify the tectonic setting of the protoliths, timing of post-metamorphic cooling, and evolution of the northern margin of the Caribbean plate.Westphalia Schist is geochemically variable, with mafic igneous protoliths or volcaniclastic sedimentary protoliths. Regardless of the protolith, the trace-element geochemistry is consistent with an island-arc tectonic environment. These rocks most likely represent metamorphosed equivalents of the regionally extensive Early Cretaceous Greater Antilles arc that is preserved discontinuously along the present-day northern margin of the Caribbean plate. Mt. Hibernia Schist shows little geochemical variability, with an igneous protolith of subalkaline basaltic composition. Flat rare-earth-element patterns and flat extended trace-element patterns are consistent with an enriched mid-ocean ridge basalt or oceanic plateau environment. However, in terms of immobile elements, Mt. Hibernia Schist is geochemically indistinguishable from nearby ca. 90 Ma basalt of the Bath-Dunrobin Formation, which is a product of Caribbean plate–forming ocean plateau magmatism; i.e., Caribbean large igneous province. Hence, an ocean plateau environment is inferred for the Mt. Hibernia protolith.The Westphalia and Mt. Hibernia Schists are currently juxtaposed along the Blue Mountain fault, yet were subjected to very different subduction-related metamorphic histories. Stratigraphic relationships require that the metamorphic rocks were uplifted, and exposed at the surface by the Early Paleocene. 40Ar/39Ar ages indicate that the two units were affected differently by burial metamorphism related to Paleocene–Early Eocene transtensional tectonics. Final juxtaposition of Westphalia Schist and Mt. Hibernia Schist was accomplished through a combination of vertical and horizontal displacements during Neogene transpression along the Plantain Garden fault. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.