Stable-isotope record of organic carbon from an evolving carbonate banktop, Bight of Abaco, Bahamas

Abstract

Research Article| August 01, 1990 Stable-isotope record of organic carbon from an evolving carbonate banktop, Bight of Abaco, Bahamas Kenneth A. Rasmussen; Kenneth A. Rasmussen 1Curriculum in Marine Sciences, 12-5 Venable Hall, CB 3300, University of North Carolina, Chapel Hill, North Carolina 27599-3300 Search for other works by this author on: GSW Google Scholar Robert I. Haddad; Robert I. Haddad 2NASA-Ames Research Center, Moffett Field, California 94035 Search for other works by this author on: GSW Google Scholar A. Conrad Neumann A. Conrad Neumann 1Curriculum in Marine Sciences, 12-5 Venable Hall, CB 3300, University of North Carolina, Chapel Hill, North Carolina 27599-3300 Search for other works by this author on: GSW Google Scholar Geology (1990) 18 (8): 790–794. https://doi.org/10.1130/0091-7613(1990)018<0790:SIROOC>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Kenneth A. Rasmussen, Robert I. Haddad, A. Conrad Neumann; Stable-isotope record of organic carbon from an evolving carbonate banktop, Bight of Abaco, Bahamas. Geology 1990;; 18 (8): 790–794. doi: https://doi.org/10.1130/0091-7613(1990)018<0790:SIROOC>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 SocietyGeology Search Advanced Search Abstract The stable-isotope composition (δ13C) of total organic carbon (TOC) was measured as a function of depth throughout a 217-cm-thick sequence of Holocene carbonate sediment within the Bight of Abaco lagoon, Little Bahama Bank. Biofacies and lithofacies analyses indicate progressive banktop submergence and paleoenvironmental response during Holocene sea-level rise. Stable-isotope values shift markedly from -27.7‰ within the 7900 B.P. paleosol at the base of the core to -11.1‰ at the present-day sediment-water interface. An abrupt excursion toward heavy-isotope values records the first establishment of Thalassia seagrass upon open-marine flooding. A multitracer approach, combining biofacies, lithofacies, and stable-isotope analysis of TOC confirms that the dramatic +17‰ shift observed in δ13C was a direct result of sea-level rise and associated environmental changes over the banktop; there is little evidence of spurious diagenetic overprint. Stable-isotope analyses of organic carbon may enhance the reconstruction of carbonate sequences by revealing a distinctive geochemical signature of banktop flooding, including the onset of growth of otherwise unpreservable Thalassia seagrass. 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.