Determination of the ground water divide in the karst aquifer of Yucatan, Mexico, combining geochemical and hydrogeological data

Abstract

The aquifer of the peninsula of Yucatan is a karstic aquifer characterized by its high permeability. Karst features such as underground channels and caverns (cenotes) are widely present throughout the peninsula. However, there is an accumulation of cenotes along a circular line, the Ring of Cenotes. The ring is related to the crater of Chicxulub, a buried impact structure that dates from the Kff boundary. The Ring of Cenotes represents on several segments a high permeability zone and is assumed to act as an underground river that collects ground water and brings it to its two intersection points with the coast line near Celestun and Dzilam de Bravo. Based on hydrogeological data, a dividing zone is described that hydraulically separates two segments of the Ring. Using the S04/Cl ratio as a natural tracer, ground water flow directions in the study area are described. Combining the results, the location of the ground water divide of the underground river system is found at the southern part of the study area, crossing the Ring of Cenotes near the village of Abala.