March 12, 2003
The above photo shows a cenote (say-no-tay) in the Yucatan Peninsula of Mexico. Cenotes are sinkholes formed from acidic water flowing through underground rivers in the limestone bedrock of the area. There are several different stages of cenote formation. Initially, the softer limestone is dissolved away leaving an underground cavern with a thin roof in what is called a solution cavern. In a young cenote, the roof collapses, leaving a huge water-filled hole. In a mature cenote, such as the Sacred Cenote shown above, thousands of years of erosion have worn down the limestone, partially filling the sinkhole. The Sacred Cenote is located near the ancient Mayan city of Chichèn Itzà, on the Yucatan Peninsula of Mexico. At one time it was used for animal and human sacrifices to appease the rain god, Chac, and the jaguar spirit, Balam. The word cenote comes from the Mayan word dzonot. Cenotes were very important to the Mayan people, and in addition to being places of sacrifice, were an important source of drinking and irrigation water.