Anatomy of a bioclastic grainstone megashoal (Middle Silurian, southern Ontario) revealed by ground-penetrating radar (1993)

Research Article| March 01, 1993 Anatomy of a bioclastic grainstone megashoal (Middle Silurian, southern Ontario) revealed by ground-penetrating radar Brian R. Pratt; Brian R. Pratt 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada Search for other works by this author on: GSW Google Scholar Andrew D. Miall Andrew D. Miall 2Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Brian R. Pratt 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada Andrew D. Miall 2Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1993) 21 (3): 223–226. https://doi.org/10.1130/0091-7613(1993)021<0223:AOABGM>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Brian R. Pratt, Andrew D. Miall; Anatomy of a bioclastic grainstone megashoal (Middle Silurian, southern Ontario) revealed by ground-penetrating radar. Geology 1993;; 21 (3): 223–226. doi: https://doi.org/10.1130/0091-7613(1993)021<0223:AOABGM>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 Porous grainstones deposited as offshore carbonate sand shoals are important hydrocarbon reservoirs, but little is known about their internal architecture and its effect on reservoir heterogeneity. The Middle Silurian Amabel Formation, exposed along the Niagara Escarpment of southern Ontario, provides an unparalleled opportunity to examine such a deposit in three dimensions with photomosaics and ground-penetrating radar. The Amabel is a dolomitized bioclastic grainstone unit up to 25 m thick, composed mainly of crinoid ossicles. It thins and grades westward to thin-bedded argillaceous dolostones. Although previously assumed to be reefal, the undulating and oblique bedding that dominates the internal geometry was caused by vertical and lateral accretion on hummocky topography and scour surfaces. Some scours are huge—as much as 15 m deep—and attest to the dramatic nature of sediment movement by storms and hurricanes. Ground-penetrating radar successfully detects the large-scale bedding pattern and, in conjunction with outcrop observations, has potential for mapping the three-dimensional architecture of ancient lithified deposits. 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.