Beyond whole-rock geochemistry of shales: The importance of assessing mineralogic controls for revealing tectonic discriminants of multiple sediment sources for the Ouachita Mountain flysch deposits

Abstract

Research Article| July 01, 2000 Beyond whole-rock geochemistry of shales: The importance of assessing mineralogic controls for revealing tectonic discriminants of multiple sediment sources for the Ouachita Mountain flysch deposits Matthew W. Totten; Matthew W. Totten 1Department of Geology and Geophysics, University of New Orleans, New Orleans, Louisiana 70148, USA Search for other works by this author on: GSW Google Scholar Mark A. Hanan; Mark A. Hanan 1Department of Geology and Geophysics, University of New Orleans, New Orleans, Louisiana 70148, USA Search for other works by this author on: GSW Google Scholar Barry L. Weaver Barry L. Weaver 2School of Geology and Geophysics, University of Oklahama, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2000) 112 (7): 1012–1022. https://doi.org/10.1130/0016-7606(2000)112<1012:BWGOST>2.0.CO;2 Article history received: 09 Dec 1998 rev-recd: 13 Oct 1999 accepted: 17 Nov 1999 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 Matthew W. Totten, Mark A. Hanan, Barry L. Weaver; Beyond whole-rock geochemistry of shales: The importance of assessing mineralogic controls for revealing tectonic discriminants of multiple sediment sources for the Ouachita Mountain flysch deposits. GSA Bulletin 2000;; 112 (7): 1012–1022. doi: https://doi.org/10.1130/0016-7606(2000)112<1012:BWGOST>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 origin of the Ouachita Mountains has been the focus of significant debate for decades. Considerable confusion also exists concerning the provenance of the Carboniferous flysch of the Ouachitas.Trace-element geochemistry of shales from the Stanley Group delineates the provenance of the sediments and provides clues to the plate tectonic evolution of the southern continental margin during Mississippian time. Th/Sc and Cr/Th ratios indicate a cratonic source for the majority of the Stanley Group sedimentary rocks. However, in several samples, low Th/Sc ratios and high Cr/Th ratios suggest a contribution from a mafic source. Using element ratio diagrams, all of the samples plot along a curve consistent with a two-component mixing model, consisting of a dominant felsic and a subordinate mafic source.The heavy-mineral fraction of these shales sequester many of the trace elements used in whole-rock studies. Monazite is ubiquitous in trace amounts and is the probable site for much of the rare earth elements in the whole rock. The occurrence of monazite almost exclusively in sialic igneous rocks implies that Sm/Nd isotopic signatures are not sensitive to sediment input from more mafic sources. In some Stanley shale samples, chromite and Mn oxides were identified and positively identify an oceanic crustal component as a source of Stanley Group sediment. The results of this study emphasize the importance of determining the mineralogic sites of trace elements, and realization of specific mineralogic contributions from mafic or sialic tectonic provenances. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.