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Holocene ooids of Aitutaki Atoll, Cook Islands, South Pacific

2009; Geological Society of America; Volume: 37; Issue: 11 Linguagem: Inglês

10.1130/g30332a.1

1943-2682

Eugene C. Rankey, Stacy Reeder,

Geological and Geophysical Studies

Research Article| November 01, 2009 Holocene ooids of Aitutaki Atoll, Cook Islands, South Pacific Eugene C. Rankey; Eugene C. Rankey 1Department of Geology, 1475 Jayhawk Blvd., 120 Lindley Hall, University of Kansas, Lawrence, Kansas 66045, USA Search for other works by this author on: GSW Google Scholar Stacy Lynn Reeder Stacy Lynn Reeder 2Schlumberger-Doll Research, One Hampshire Street, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Eugene C. Rankey 1Department of Geology, 1475 Jayhawk Blvd., 120 Lindley Hall, University of Kansas, Lawrence, Kansas 66045, USA Stacy Lynn Reeder 2Schlumberger-Doll Research, One Hampshire Street, Cambridge, Massachusetts 02139, USA Publisher: Geological Society of America Received: 21 Apr 2009 Revision Received: 28 May 2009 Accepted: 02 Jun 2009 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (11): 971–974. https://doi.org/10.1130/G30332A.1 Article history Received: 21 Apr 2009 Revision Received: 28 May 2009 Accepted: 02 Jun 2009 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Eugene C. Rankey, Stacy Lynn Reeder; Holocene ooids of Aitutaki Atoll, Cook Islands, South Pacific. Geology 2009;; 37 (11): 971–974. doi: https://doi.org/10.1130/G30332A.1 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 Although oolitic sands are widespread throughout the Phanerozoic carbonate rock record, and they are abundant in some modern shallow-marine carbonate systems, recent ooids have not been recognized from any locality in the Pacific Basin. On Aitutaki Atoll (Cook Islands, South Pacific), oolitic sands occur in water depths of 2.1–6.3 m within the lagoon and, less abundantly, on shallower reef aprons. Most ooids are between 150 and 300 μm in diameter, have between 1 and 25 concentric to irregular laminae, and occur with peloids and skeletal grains. Cortical laminae include Mg-calcite crystals with radial, tangential, and random orientations. The occurrence and distribution of oolitic sands on Aitutaki are facilitated by a convergence of hydrodynamic and chemical factors. Wave-driven currents, combined either with flow separation over a sharp increase in depth at the reef apron–lagoon interface or with oceanward flow in the lee of islands, serve to transport ooids without flushing them from the system. Here, pH, alkalinity, and carbonate supersaturation are at some of the highest levels in the tropical Pacific. The restricted occurrence of Holocene oolitic sands in areas of the Pacific and Atlantic Basins with elevated pH and total alkalinity reflects the importance of carbonate saturation thresholds in limiting the spatial distribution of these sands in modern shallow-marine settings. These recent examples are consistent with interpretations of the importance of these variables in determining the distribution, abundance, and cortical mineralogy of oolitic sands throughout the Phanerozoic stratigraphic record of carbonate accumulation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.