Description

Cenote Ik Kil.
Cenote (from the Mayan ts'ono'ot: 'hole with water') is a flooded sinkhole of karstic origin. There are several types of cenotes: open-air, semi-open, and underground or in a cave. This classification is directly related to the age of the cenote, being the mature cenotes those that are completely open and the youngest ones that still keep their dome intact. Like many other geomorphological structures, cenotes are transitory structures that can eventually end up filled and dried, becoming part of what is known as a paleokarst underground river.

Its morphology is typically subcircular, with abrupt walls. Due to the evolution of the karstic massif, the cenote begins as an underground chamber produced by the dissolution of limestone rock by the infiltration of rainwater. Finally, as the cavity increases in size, the cenote may end up coming to the surface due to the collapse of the dome. The cenotes were formed during the times of lowering of the sea level during the glacial pulses of the Pleistocene. Cenotes are, in most cases, widening of complex underground fluvial networks. In these, marine water, denser than fresh, can penetrate through the bottom of the water table. For this reason, there are cenotes in which, after a certain depth, the water changes from fresh to salty, even many kilometers from the coast. This contact surface between fresh and marine water is called the halocline, and it causes interesting visual effects.