Continental mafic magmatism of different ages in the same terrane: Constraints on the evolution of an enriched mantle source

Abstract

Research Article| April 01, 2007 Continental mafic magmatism of different ages in the same terrane: Constraints on the evolution of an enriched mantle source J. Brendan Murphy; J. Brendan Murphy 1Department of Earth Sciences, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5, Canada Search for other works by this author on: GSW Google Scholar Jaroslav Dostal Jaroslav Dostal 2Department of Geology, St. Mary's University, Halifax, Nova Scotia B3H 3C3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information J. Brendan Murphy 1Department of Earth Sciences, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5, Canada Jaroslav Dostal 2Department of Geology, St. Mary's University, Halifax, Nova Scotia B3H 3C3, Canada Publisher: Geological Society of America Received: 07 Jun 2006 Revision Received: 23 Nov 2006 Accepted: 27 Nov 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2007) 35 (4): 335–338. https://doi.org/10.1130/G23072A.1 Article history Received: 07 Jun 2006 Revision Received: 23 Nov 2006 Accepted: 27 Nov 2006 First Online: 09 Mar 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. Brendan Murphy, Jaroslav Dostal; Continental mafic magmatism of different ages in the same terrane: Constraints on the evolution of an enriched mantle source. Geology 2007;; 35 (4): 335–338. doi: https://doi.org/10.1130/G23072A.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 The Antigonish Highlands, Nova Scotia, are within the Avalon terrane of the northern Appalachians and contain four distinct episodes of rift-related magmatism: Neoproterozoic, Cambrian, Middle Ordovician, and Late Devonian. All four magmatic suites are composed of basalts and subordinate crustally derived felsic rocks. The mafic rocks of these suites, which do not appear to be significantly contaminated by continental crust, display similar geochemical and Sm-Nd isotopic characteristics consistent with an enriched mantle source that was metasomatically enriched prior to the oldest rifting event, probably between 0.8 and 1.1 Ga. These data also imply that the Avalonian crust and its subcontinental lithospheric mantle remained coupled during four magmatic events. Because the earliest phases of magmatism occurred when Avalonia was located along the Gondwanan margin, and the latest phases after Avalonia accreted to Laurentia, the coupling of crust and mantle in the Antigonish Highlands suggests that the migration of Avalonia did not completely detach its lithospheric mantle from its crustal cover. This study demonstrates the importance of comparing magmatism of different ages in the same terrane. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.