Chemical mass-wasting of the northern Yucatan Peninsula by groundwater dissolution

Abstract

Research Article| May 01, 1980 Chemical mass-wasting of the northern Yucatan Peninsula by groundwater dissolution Bruce B. Hanshaw; Bruce B. Hanshaw 1U.S. Geological Survey, 431 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar William Back William Back 1U.S. Geological Survey, 431 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar Geology (1980) 8 (5): 222–224. https://doi.org/10.1130/0091-7613(1980)8<222:CMOTNY>2.0.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 Bruce B. Hanshaw, William Back; Chemical mass-wasting of the northern Yucatan Peninsula by groundwater dissolution. Geology 1980;; 8 (5): 222–224. doi: https://doi.org/10.1130/0091-7613(1980)8<222:CMOTNY>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 The northern part of the Yucatan Peninsula is a relatively flat, low-lying carbonate terrane with no geomorphic expressions of stream channels. It is estimated that mean annual recharge to the groundwater system is 150 mm. For the 65,500 km2 study area, mean annual discharge (equivalent to recharge) is 9.8 × 109 m3, or 8.6 × 106 m3 for each 1 km of the 1,100-km-long coastline. In the interior of the peninsula, the recharging water annually dissolves about 37.5 t (metric tons) of calcite per 1 km2. When the groundwater has become saturated with calcite, little additional water-rock interaction occurs until the active mixing (dispersion) zone is reached near the coastline.Theoretical calculations and laboratory experiments have shown that when two waters, each calcite saturated and with different salinities, are mixed, the resulting solution generally becomes undersaturated with calcite and, therefore, is capable of dissolving additional calcite. On the basis of our study of the Xel Ha lagoon on the east coast of Yucatan, we calculate that as much as 1.2 mmol/L additional calcite can be dissolved in the brackish groundwater zone of dispersion. This indicates that if the total solution potential of the amount of water discharging at Xel Ha has focused within the lagoon area, the lagoon could be chemically incised in less than 3,000 yr. We postulate that chemical mass wasting by dissolution in the zone of groundwater mixing is an important geomorphic process in coastal areas of limestone terranes. 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.