ABSTRACT
This demonstrates the geochemical significance of the mixing zone and formulates a hypothesis for the geomorphic evolution of part of the eastern coastline of the Yucatan, a stretch extending ~ 100 km from near Puerto Morelos southwest to Tulum. Combining geochemical theory with the cyclic flow of the mixing zone demonstrates which part of the groundwater regime is subsaturated and therefore has the greatest potential for porosity development. The mixed groundwater became subsaturated with respect to calcite and dissolved the limestone. A scientific and engineering need to understand the physics of seawater encroachment into coastal aquifers has had a significant impact on development of the science of hydrogeology. Geologic significance of subsaturation can be emphasized by remembering that every marine limestone containing freshwater has been subjected to dissolution and diagenesis caused by the mixing zone phenomenon at least once.
