|Coordinates:||22.9934 N -98.1615 W|
|No:||110 (list of all attractions)|
|Category:||Sinkholes, Lakes, bays and streams|
|Address:||North America, Mexico, Tamaulipas, southern part of the state, 12 km north-west from Aldama town|
|Alternate names:||Cenote Verde|
One of comparatively large sinkholes in the unique Sistema Zacatón karst field is Poza Verde.
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 a double bottom
Poza Verde has a diameter of 120 - 150 m. It is hard to access - beautiful blue water is encircled by tall limestone cliffs.
Water in this lake is somewhat cooler than in neighboring cenotes - 28 - 29° C. Unlike to other sinkholes nearby, water here is stratified, with chemocline. Surface water is not acidic. Thus Poza Verde seems to be more like a "normal lake".
Depth of sinkhole is 40 - 48 m what is comparatively little if compared to neighbouring sinkholes. There have been attempts without success to find any large side passages. Bottom of sinkhole is extremely level.
This is explained by the fact that the bottom of sinkhole is several metres thick travertine lid formed at some earlier time when water level was considerably lower. Below this lid there is located another void filler with thermal water.