Hydrogeology of the Yucatán Peninsula.

Abstract

The northern Yucatan Peninsula, Mexico is a partially emergent carbonate platform with an extensive continental shelf. Mesozoicand Cenozoic-era limestone, dolomite, and anhydrite overlie deeply buried Paleozoic-era crystalline and sedimentary rocks. The peninsular aquifer system has developed in nearly horizontal, highly-permeable rocks that are dominantly Tertiary period limestones and dolostones. These are thinly covered by Holocene and Pleistocene epoch carbonate rocks and sediments along the coast, as well as by a thin cover of soil inland. Rocks are both porous and permeable, and permeability exists on two scales: cavernous (fracture) and intergranular (porous medium). Exceptionally permeable zones are developed along faults, perhaps generated by Eocene epoch Caribbean plate movements in the east and, in the northwest, by crustal relaxation and/or basin loading caused by the impact of a large meteorite or comet (Hildebrand et al. 1995). An additional prominent fault, the Ticul Fault Zone (Figure 7.1), whose origin is difficult to assign to a specific tectonic event, is present in the northwest portion of the peninsula. These faults are important as channels for groundwater movement.