|Coordinates:||23.0008 N -98.1636 W|
|No:||115 (list of all attractions)|
|Category:||Sinkholes, Lakes, bays and streams|
|Values:||Geology, Biology, Unexplained|
|Address:||North America, Mexico, Tamaulipas, southern part of the state, 13 km north-west from Aldama town|
|Depth:||2 - 4 m, below one more void deeper than 45 m|
One of the largest sinkholes in the unique Sistema Zacatón is Poza Tule. This sinkhole has a diameter of some 200 - 250 m.
Sistema Zacatón is area with incredible characteristics unparalleled in the world. In total this area contains some 20 unusual features - sinkholes, caves, springs created by deep groundwater heated by volcanic processes. Karstification processes here continue today as well - acidic groundwater continues to strip away the limestone and deposits it in unusual travertine formations.
Sinkhole with triple bottom
Rims of Poza Tule are enclosed with a belt of dense reed vegetation, the plain bottom is covered with a shallow water. This waterbody was reached after hard cutting through bush in March, 2002.
Geophysical investigations showed that below the shallow pool is located travertine layer with thickness fluctuating from less than 2 m to more than 4 m. Below this travertine lid is up to 45 m deep water-filled void. Below it there is the next travertine lid - second cap!
Such sealed voids full with thermal water may serve as ideal isolated habitats for anoxic bacteria from the previous ice age times.