Transformation of aragonite-dominated lime muds to microcrystalline limestones

Abstract

Research Article| July 01, 1984 Transformation of aragonite-dominated lime muds to microcrystalline limestones Zakaria Lasemi; Zakaria Lasemi 1Department of Geology, University of Illinois, Urbana, Illinois 61820 Search for other works by this author on: GSW Google Scholar Philip A. Sandberg Philip A. Sandberg 1Department of Geology, University of Illinois, Urbana, Illinois 61820 Search for other works by this author on: GSW Google Scholar Author and Article Information Zakaria Lasemi 1Department of Geology, University of Illinois, Urbana, Illinois 61820 Philip A. Sandberg 1Department of Geology, University of Illinois, Urbana, Illinois 61820 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1984) 12 (7): 420–423. https://doi.org/10.1130/0091-7613(1984)12<420:TOALMT>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 Email Tools Icon Tools Get Permissions Search Site Citation Zakaria Lasemi, Philip A. Sandberg; Transformation of aragonite-dominated lime muds to microcrystalline limestones. Geology 1984;; 12 (7): 420–423. doi: https://doi.org/10.1130/0091-7613(1984)12<420:TOALMT>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 SocietyGeology Search Advanced Search Abstract Scanning electron microscopy of textures in several well-lithified Pleistocene "micrites" (mixed micrite and microspar) from south Florida and the Bahamas shows significant diagenetic alteration of the lime-mud precursors. The dominance of aragonite in those precursor muds is supported by the surprising presence of abundant aragonite relics in the neomorphic calcite crystals (confirmed by Feigl stain, X-ray and electron diffraction). Polished, very lightly etched surfaces of neomorphic calcite crystals, even in the microspar, show aragonite relics and pits, both absent in coexisting void-fill cements. Similarities between micrite and microspar crystals indicate their common origin through a one-step neomorphic process of calcitization. That is, the mud did not first calcitize to micrite and then alter to microspar by aggrading neomorphism. This conclusion has more general implications for the interpretation of the origins of other, older microsparitic carbonates. Both early calcitization and concurrent early meteoric cementation were significant in producing the Florida-Bahamas "micrites" studied, which have low porosities similar to those found in most ancient fine-grained limestones. These low porosities, despite the absence of significant overburden, indicate that major porosity reduction without compaction can occur in calcitized aragonite-dominated muds. 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.