The Kingston terrane, southern New Brunswick, Canada: Evidence for an Early Silurian volcanic arc

Research Article| August 01, 2002 The Kingston terrane, southern New Brunswick, Canada: Evidence for an Early Silurian volcanic arc Sandra M. Barr; Sandra M. Barr 1Department of Geology, Acadia University, Wolfville, Nova Scotia B0P 1X0, Canada Search for other works by this author on: GSW Google Scholar Chris E. White; Chris E. White 2Nova Scotia Department of Natural Resources, P.O. Box 698, Halifax, Nova Scotia B3J 2T9, Canada Search for other works by this author on: GSW Google Scholar Brent V. Miller Brent V. Miller 3Department 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 Author and Article Information Sandra M. Barr 1Department of Geology, Acadia University, Wolfville, Nova Scotia B0P 1X0, Canada Chris E. White 2Nova Scotia Department of Natural Resources, P.O. Box 698, Halifax, Nova Scotia B3J 2T9, Canada Brent V. Miller 3Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599-3315, USA Publisher: Geological Society of America Received: 16 Aug 2001 Revision Received: 25 Feb 2002 Accepted: 26 Mar 2002 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2002) 114 (8): 964–982. https://doi.org/10.1130/0016-7606(2002)114<0964:TKTSNB>2.0.CO;2 Article history Received: 16 Aug 2001 Revision Received: 25 Feb 2002 Accepted: 26 Mar 2002 First Online: 01 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 Sandra M. Barr, Chris E. White, Brent V. Miller; The Kingston terrane, southern New Brunswick, Canada: Evidence for an Early Silurian volcanic arc. GSA Bulletin 2002;; 114 (8): 964–982. doi: https://doi.org/10.1130/0016-7606(2002)114<0964:TKTSNB>2.0.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 The fault-bounded Kingston terrane of southern New Brunswick consists of felsic and less abundant mafic volcaniclastic rocks and flows and minor interbedded sedimentary rocks of the Kingston Group intruded by mainly granitic plutons and abundant younger mafic sheets. The granitic plutons form about half of the terrane and are characterized by fine grain size and typically granophyric and porphyritic textures, indicative of high-level emplacement. Mafic sheets were emplaced in the granitic plutons and parallel to primary layering in the Kingston Group, which is typically steeply dipping and trends northeast to north-northeast. Hence, in contrast to some earlier interpretations, the Kingston terrane does not consist of a bimodal dike complex. The Kingston Group, granitic rocks, and mafic sheets contain mineral assemblages consistent with metamorphism to upper greenschist–lower amphibolite facies.New U-Pb (zircon) ages of 442 ± 6 Ma from a dacitic tuff unit and 437 ± 10 Ma from a granitic pluton corroborate previous U-Pb dates that had suggested that the volcanic and granitic rocks in the Kingston terrane are Early Silurian, rather than Precambrian, as had been earlier assumed. The felsic volcanic and granitic rocks are interpreted to be comagmatic on the basis of their field relationships and similar U-Pb ages and chemical character. Compositions of both the felsic rocks and less abundant mafic and intermediate and mafic rocks are consistent with calc-alkalic affinity and emplacement in a continental-margin volcanic arc, herein termed the Kingston arc. A U-Pb date of 435 ± 5 Ma was also obtained from compositionally similar granite that forms a dike in an adjacent fault-bounded amphibolite-facies metasedimentary unit. The similarity in age and composition of the granite dike suggests a link between these metasedimentary rocks and the Kingston terrane, possibly as part of an accretionary complex. If so, its location southeast of the Kingston terrane indicates that subduction was to the present northwest. Mafic sheets in the Kingston terrane are tholeiitic but have some arc-like characteristics, consistent with their origin in a former arc setting, but the sheets were likely emplaced in a subsequent extensional setting. The compositional similarity of the mafic sheets to Late Silurian mafic volcanic rocks and plutons of the Coastal Maine magmatic province suggests that they may be related.A possible model for evolution of the Kingston terrane is proposed, wherein the Kingston Group and related granite formed in an Early Silurian arc on the margin of Ganderia, as represented by the New River terrane of late Precambrian and early Paleozoic age. Northwestward subduction culminated in collision between the Kingston arc and a continental block now represented by the Brookville terrane to the southeast. Subsequent transpressive mo tions in the Late Silurian may have been responsible for the crustal- scale extensional environment in which the Coastal Maine magmatic province was formed, including emplacement of mafic dikes into the deformed former Kingston arc. Transpressive motions—related to juxtaposition of the Avalon and Meguma terranes with the previously accreted, more inboard terranes—continued through the Devonian and into the Carboniferous. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.