Dolomitization of Holocene Mg-calcite supratidal deposits, Ambergris Cay, Belize

Research Article| February 01, 1987 Dolomitization of Holocene Mg-calcite supratidal deposits, Ambergris Cay, Belize S. J. MAZZULLO; S. J. MAZZULLO 1Geological Consultants, Midland, Texas 79701 Search for other works by this author on: GSW Google Scholar A. M. REID; A. M. REID 1Geological Consultants, Midland, Texas 79701 Search for other works by this author on: GSW Google Scholar J. M. GREGG J. M. GREGG 2St. Joe Minerals Corp., Viburnum, Missouri 65566 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1987) 98 (2): 224–231. https://doi.org/10.1130/0016-7606(1987)98<224:DOHMSD>2.0.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 S. J. MAZZULLO, A. M. REID, J. M. GREGG; Dolomitization of Holocene Mg-calcite supratidal deposits, Ambergris Cay, Belize. GSA Bulletin 1987;; 98 (2): 224–231. doi: https://doi.org/10.1130/0016-7606(1987)98<224:DOHMSD>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 Dolomitized crusts and associated sediments 845–2925 yr old on Ambergris Cay, Belize, Central America, compose a significant portion of the Holocene sediment section on many supratidal flats. The dolomitic sections are as thick as 0.7 m and contain an average of 70% calcic dolomite. Dolomite occurs as a replacement of high-Mg calcite micrite matrix and allochems, and as passively precipitated cements. Isotopic analyses suggest that dolomitization appears to be promoted primarily by reactions of the magnesian calcite supratidal sediments with essentially near-normal marine waters. The effects of seasonal influxes of meteoric and hybrid fluids, however, are also clearly evident in the crusts as indicated by isotopes, dolomite-crystal etching, the selective leaching of aragonite, and the local loss of Mg2+ from the host micrite and included skeletal fragments. The amounts, rapid rates of dolomitization, and initial Mg-calcite mineralogy of the sediments make the Ambergris Cay supratidal flats exceptional in the Holocene, and this area may be a model for the genesis of some ancient peritidal dolomites. 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.