The caves of the Naica Mine (Chihuahua, Mexico) contain some of the World's most impressive secondary hypogene speleologenetic processes actually mainly known for their gypsum crystals that in the last ten years have attracted attention of scientific community. In fact, the Naica cave patterns are not interpreted as strictly hypogene, but could have formed in a first stage by dissolution in meteoric water conditions along fractures, faults and bedding plains affecting the carbonate massif and, only later, superimposed by hypogenic features related to the mobilization of the polysulphide mineralization that filled the karst voids. The ore deposits in Naica is of hydrothermal origin, resulted from the presence of a magmatic activity that took place about 26 million years ago, probably corresponding with the last magmatic stages in the Sierra Madre Occidental. Intrusion of this body and interaction with connate water of the sedimentary sequence created a hydrothermal system with high metal transport capacity brines. The interaction between hot water of meteoric origin (rising along main fault of Sierra de Naica mountain) and anhydrite lens, formed in the limestone during later stage of ore body formation, led to the formation of rare and complex speleothems. For these reasons, since 2006 Naica caves are part of a multidisciplinary research project that covers main research fields, such as geology, physics, biology, and more recently, detailed studies have been carried out including mineralogy, geochemistry and hydrogeology. A review on the state of the art knowledge on hypogenic features of Naica caves is presented.
Multidisciplinary study of the caves of Naica (Mexico): a review.
Laura Sanna;
2013
Abstract
The caves of the Naica Mine (Chihuahua, Mexico) contain some of the World's most impressive secondary hypogene speleologenetic processes actually mainly known for their gypsum crystals that in the last ten years have attracted attention of scientific community. In fact, the Naica cave patterns are not interpreted as strictly hypogene, but could have formed in a first stage by dissolution in meteoric water conditions along fractures, faults and bedding plains affecting the carbonate massif and, only later, superimposed by hypogenic features related to the mobilization of the polysulphide mineralization that filled the karst voids. The ore deposits in Naica is of hydrothermal origin, resulted from the presence of a magmatic activity that took place about 26 million years ago, probably corresponding with the last magmatic stages in the Sierra Madre Occidental. Intrusion of this body and interaction with connate water of the sedimentary sequence created a hydrothermal system with high metal transport capacity brines. The interaction between hot water of meteoric origin (rising along main fault of Sierra de Naica mountain) and anhydrite lens, formed in the limestone during later stage of ore body formation, led to the formation of rare and complex speleothems. For these reasons, since 2006 Naica caves are part of a multidisciplinary research project that covers main research fields, such as geology, physics, biology, and more recently, detailed studies have been carried out including mineralogy, geochemistry and hydrogeology. A review on the state of the art knowledge on hypogenic features of Naica caves is presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
