Mexico’s Yucatan Peninsula is one of the world’s most fascinating geological and ecological wonders. First shaped by the impact of a huge asteroid several million years ago, the region has also been shaped by a variety of climatic and geologic events over the course of time, making the true history of the Yucatan Peninsula difficult to understand.
This uncertainty is due in part to a need for additional investigative excavations to understand the unique geology of the Yucatan platform, which has minimal exposed rock strata and semi-inaccessible inland terrain, thanks to the countless acres of lush tropical jungle. Much of the data that has been collected dates back to the early 1970s, when Petroleos Mexicanos (PEMEX) was looking for oil reserves in the Yucatan Peninsula and drilled a number of exploratory wells. In addition to providing information about oil the drill sites showed that the entire area rested atop an enormous limestone platform that slopes toward the Mexican Caribbean Sea, where it is necessary to travel quite a way offshore before reaching deep water.
The limestone platform of the Yucatan Peninsula is honeycombed with many caves and sinkholes, which are known as cenotes, and there are no major rivers to be found above ground in the entire region. In fact, groundwater can be found anywhere from 5 to 50 feet below the surface throughout most of the Yucatan Peninsula.
Also of interest, more than 10,000 years ago the large drop in sea levels during the last Ice Age, caused the world’s oceans to crest at anywhere from 100 to 300 feet below their current levels, meaning that many of the underground caves and rivers of Mexico’s Yucatan platform would have been dry. As the Ice Age came to an end and the planet began to warm up, the glaciers melted and sea levels began to rise, flooding the area once again and creating the many underground rivers we can find today. In addition, a variety of artifacts have been found in the caves, some dating back as many as 7,000 years.