Tephra layers as correlation tools of Neogene coal-bearing strata from the Kenai lowland, Alaska

Abstract

Research Article| March 01, 1995 Tephra layers as correlation tools of Neogene coal-bearing strata from the Kenai lowland, Alaska Linda M. Reinink-Smith Linda M. Reinink-Smith 1Mineral Industry Research Laboratory and Department of Geology and Geophysics, University of Alaska Fairbanks, Fairbanks, Alaska 99775 Search for other works by this author on: GSW Google Scholar Author and Article Information Linda M. Reinink-Smith 1Mineral Industry Research Laboratory and Department of Geology and Geophysics, University of Alaska Fairbanks, Fairbanks, Alaska 99775 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1995) 107 (3): 340–353. https://doi.org/10.1130/0016-7606(1995)107<0340:TLACTO>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Linda M. Reinink-Smith; Tephra layers as correlation tools of Neogene coal-bearing strata from the Kenai lowland, Alaska. GSA Bulletin 1995;; 107 (3): 340–353. doi: https://doi.org/10.1130/0016-7606(1995)107<0340:TLACTO>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 Thirty-two tephra layers, exposed in coal beds of the Miocene and Pliocene Beluga and Sterling Formations along the shores of the Kenai lowland on the northwestern Kenai Peninsula, Alaska, were studied in detail to improve the geochronology and regional correlation of the Sterling Formation and test prior correlations that were based on palynology and physical tracing of beds over short distances. Published radiogenic isotope data suggest an age span of ∼4 m.y. for the Sterling Formation at this location but give discordant ages for individual samples depending on dating techniques.A crystal-rich tephra layer near the middle of the section was traced across the Kenai lowland as one or two ash falls based on stratigraphic position, inertinite contents of adjacent coal, geochemical and mineralogical analyses, and individual characteristics. A pumice-rich layer deposited near the top of the Sterling Formation is preserved at two localities on the northwestern and southeastern sides of the Kenai lowland. Geochemical similarities, similar glass morphologies, and an absence of opaque phases characterize this layer as a single ash fall and allow correlation. On a regional scale, these correlations concur with previous correlations and show that a shallow anticline with a northwest-southeast–trending axis extends across the Kenai lowland. 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.