Porosity development in coastal carbonate aquifers

Research Article| March 01, 1989 Porosity development in coastal carbonate aquifers Ward E. Sanford; Ward E. Sanford 1U.S. Geological Survey, M.S. 431, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar Leonard F. Konikow Leonard F. Konikow 1U.S. Geological Survey, M.S. 431, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar Geology (1989) 17 (3): 249–252. https://doi.org/10.1130/0091-7613(1989)017<0249:PDICCA>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 Ward E. Sanford, Leonard F. Konikow; Porosity development in coastal carbonate aquifers. Geology 1989;; 17 (3): 249–252. doi: https://doi.org/10.1130/0091-7613(1989)017<0249:PDICCA>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 Geochemical mixing theory suggests that the mixing of seawater and calcite-saturated fresh ground water can result in a solution that is undersaturated with respect to calcite. Previous studies of the mixing of such waters in carbonate rocks along certain coastlines have indicated that this mixing effect may be responsible for significant amounts of calcite dissolution and porosity development. In this study, potential rates of porosity development by calcite dissolution are assessed by combining geochemical mixing theory with the hydrodynamics of fresh-water-salt-water mixing zones in a coupled reaction- transport model. Results from the reaction-path model PHREEQE are used with a variable-density ground-water flow and solute-transport model to simulate an idealized cross section of a coastal carbonate aquifer. Results of the simulations indicate that the dissolution process is sensitive to fresh-water chemistry, ground-water velocities, and sea-level movement. Dissolution potential was evaluated at three field sites, and evidence from those sites is in general agreement with the simulation results. Dissolution rates indicated by the model show that under the proper conditions this dissolution mechanism can produce significant increases in porosity over relatively short spans of geologic time (tens of thousands of years). 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.