Geology of Cuevas del Aguila
Cuevas del Aguila is located in a hill of dolomite rocks that formed on a Cambrian carbonate marine platform more than 500 million years ago.
This type of rock is soluble under environmental conditions, and in contact with water can produce cavities through a slow geological process.
The circulation of groundwater related to the Avellaneda and Arenas rivers formed a series of cavities around the water table in the subsoil. The widening of these cavities produced a series of collapses of the bedrock, giving rise to the large rooms that form this cave. The last significant collapses occurred more than 75 thousand years ago.
The cave boasts a stunning array of colors and textures, setting it apart from other caves in the Iberian Peninsula, which often exhibit more monotony. This uniqueness stems from the intricate evolution—a result of repeated phases of creation and destruction—of the formations, lending a remarkable diversity to the subterranean panorama. The cave's complexity reflects a gradual yet ceaseless evolution, a testament to its ongoing transformation.
Formations
Cuevas del Águila boasts a rich array of speleothems, including stalagmites, stalactites, columns, and flowstones, as well as anthodites, eccentrics, needles, shields, and even moonmilk. This diversity in crystalline growth arises from variations in the cave's microclimate and the unique conditions in which these formations develop.
The current and past climate
The Cave has a stable atmosphere with a temperature that varies from 15 to 17ºC and a relative humidity of 100%. In the last 30 years, the temperature has changed by 2ºC as a result of the changes in the environment. Its stalagmites have revealed that the cause of the maximum extent of the glaciers in Gredos, which occurred 26 thousand years ago, were produced by a high rainfall in the region over a very cold period. Due to their special characteristics, scientists have been using Cuevas del Aguila for more than five years as a natural laboratory to study current and past climate changes.
