Geochemistry of Upper Cambrian-Lower Ordovician black shale along a northeastern Appalachian transect

Abstract

Research Article| July 01, 1993 Geochemistry of Upper Cambrian-Lower Ordovician black shale along a northeastern Appalachian transect LES R. FYFFE; LES R. FYFFE 1New Brunswick Department of Natural Resources and Energy, Geological Surveys Branch, P. O. Box 6000, Fredericton, New Brunswick, Canada E3B 5H1 Search for other works by this author on: GSW Google Scholar RON K. PICKERILL RON K. PICKERILL 2Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick, Canada E3B 5A3 Search for other works by this author on: GSW Google Scholar Author and Article Information LES R. FYFFE 1New Brunswick Department of Natural Resources and Energy, Geological Surveys Branch, P. O. Box 6000, Fredericton, New Brunswick, Canada E3B 5H1 RON K. PICKERILL 2Department of Geology, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick, Canada E3B 5A3 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1993) 105 (7): 897–910. https://doi.org/10.1130/0016-7606(1993)105<0897:GOUCLO>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation LES R. FYFFE, RON K. PICKERILL; Geochemistry of Upper Cambrian-Lower Ordovician black shale along a northeastern Appalachian transect. GSA Bulletin 1993;; 105 (7): 897–910. doi: https://doi.org/10.1130/0016-7606(1993)105<0897:GOUCLO>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 SocietyGSA Bulletin Search Advanced Search Abstract Samples of Upper Cambrian to Lower Ordovician black shale, collected in a transect extending across the Canadian Appalachians from the Humber Zone in Quebec, the Gander and Avalon Zones in New Brunswick, to the Meguma Zone in Nova Scotia, were analyzed for 40 elements, including rare earths. These geochemical data lend support to previously established plate-tectonic models of the region. They also provide information on provenance and depositional environments of sediments that are too fine grained for more traditional mineralogical and sedimentological studies.Generally high Al2O3 contents, high Al/Ti values, and steep rare-earth-element (REE) distribution patterns are consistent with a continental-margin depositional setting for shale from the Humber and Meguma Zones on opposite sides of the Iapetus ocean. Generally higher K2O contents, lower La/Th values, and lower absolute REE abundances distinguish shale of the Humber Zone deposited on the Laurentian margin from that deposited in the Meguma Zone on the Gondwanan margin. High La/Th values indicate a similar Gondwanan source for shale from both the Meguma and Avalon Zones. Shale from the Gander Zone contains less Al2O3 at increasing distances from its boundary with the Avalon Zone. Low Al/Ti and less fractionated REE distribution patterns suggest a greater component of volcanic detritus in shale of the Avalon and Gander Zones. The presence of distinctive Balto-Scandian signatures (high U, V, and Mo) in shale of the Avalon and northwestern Gander Zones is possibly related to deposition in isolated peri-Gondwanan back-arc basins during a highstand of sea level. 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.