Tectonic influence on sedimentation along the southern flank of the late Paleozoic Magdalen basin in the Canadian Appalachians: Geochemical and isotopic constraints on the Horton Group in the St. Marys basin, Nova Scotia

Abstract

Research Article| July 01, 2000 Tectonic influence on sedimentation along the southern flank of the late Paleozoic Magdalen basin in the Canadian Appalachians: Geochemical and isotopic constraints on the Horton Group in the St. Marys basin, Nova Scotia J. Brendan Murphy J. Brendan Murphy 1Department of Geology, St. Francis Xavier University, P.O. Box 5000, Antigonish, Nova Scotia B2G 2W5, Canada Search for other works by this author on: GSW Google Scholar GSA Bulletin (2000) 112 (7): 997–1011. https://doi.org/10.1130/0016-7606(2000)112<997:TIOSAT>2.0.CO;2 Article history received: 23 Jun 1998 rev-recd: 13 Aug 1999 accepted: 17 Sep 1999 first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation J. Brendan Murphy; Tectonic influence on sedimentation along the southern flank of the late Paleozoic Magdalen basin in the Canadian Appalachians: Geochemical and isotopic constraints on the Horton Group in the St. Marys basin, Nova Scotia. GSA Bulletin 2000;; 112 (7): 997–1011. doi: https://doi.org/10.1130/0016-7606(2000)112<997:TIOSAT>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 Late Devonian–Early Carboniferous St. Marys basin in mainland Nova Scotia, Canada, consists of Horton Group intracontinental clastic rocks that were deposited along the Avalon-Meguma terrane boundary during the waning stages of the Acadian orogeny and prior to terminal collision in the Appalachian orogen. These rocks represent the earliest stages of deposition along the southern flank of the composite Magdalen basin (Late Devonian to Permian) that extends over much of Maritime Canada and oversteps terrane boundaries in the Canadian Appalachians. As such, the Horton Group represents deposition in an episutural basin.The Horton Group in the St. Marys basin predominantly consists of 3000–4000 m of clastic sedimentary rocks deposited in fluviatile and lacustrine nearshore environments.Geochemical analyses of clastic rocks reveal a range of SiO2 content (60–94 wt%), high total rare earth elements and initial 87Sr/86Sr, and strongly negative ϵNd(t) (t = 360 Ma). The signature of the passive margin to active continental margin implied by standard discrimination diagrams probably is inherited largely from rocks in the source region and is not an indication of the setting in which the basin formed. Although the data indicate that some lithologies contain a minor Avalonian basement component, the geochemical and isotopic signatures of the sedimentary rocks reveal mixed sources that can be attributed largely to uplift and erosion of Meguma terrane metasedimentary and granitoid rocks immediately to the south of the St. Marys basin. Regional syntheses indicate that this uplift occurred before and during Horton Group deposition and was coeval with dextral ramping of the Meguma terrane over the Avalon terrane along the southern flank of the Magdalen basin. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.