Naica, Mun. de Saucillo, Chihuahua, Mexico
|Latitude & Longitude (WGS84):||27° 51' North , 105° 30' West|
|Latitude & Longitude (decimal):||27.85, -105.5|
|Other/historical region names associated with this locality:||Gibraltar, Maravillas, Lepanto, Siglo XX|
Some caves encountered in and near the workings of the Naica Mine are famous for giant gypsum crystals (up to 14 m in length!), among them "Cave of Swords" within the old Gibraltar Mine workings and "Cave of Crystals" at about 480m depth in the main Naica Mine workings.
Note that the upper level oxide workings of the Gibraltar, Maravillas, Lepanto, Siglo XX etc. Mines were incorporated into the Naica Mine in the mid-1950s and for the most part sealed off and abandoned. Although the name Gibraltar Shaft survives within the Naica Mine, Gibraltar (and other old mine names) no longer bear any relation to the current workings (now dominantly well below the 500 m level). Pretty much any specimen mined since the 1950s...except for crystals taken from the Cave of the Swords (and most of the gypsum crystals that have come out in that period came from caverns other than the Cave of the Swords) should be simply labeled Naica Mine, Naica, ... etc.
Distinctive sharp gypsum crystals on a dark brown hard limestone matrix come from the Chubasco Breccia Body, probably a collapsed solution cave/pipe. Chubasco lies at the end of a long exploration heading driven to chase a geophysical anomaly. There was no ore present and the drift was closed off permanently.
2015: Rumors that the Cave of the Crystals is flooded are false. Strong water inflow was encountered in deep workings in early 2015 and some of the mine has been allowed to flood, but this does not affect the Cave. Work is underway on a work-around and the mine should be back in production before long.
Mineral ListMineral list contains entries from the region specified including sub-localities
|Quaternary0 - 2.588 Ma||Quaternary sedimentary rocks|
|Early Cretaceous100.5 - 145 Ma||Early Cretaceous sedimentary|
Includes 1uK in Sverdrup Basin in Canadian Arctic Islands
|Early Cretaceous100.5 - 145 Ma|
References for regional geology:
Data provided by Macrostrat.org
Garrity, C.P., and Soller, D.R.,. Database of the Geologic Map of North America: adapted from the map by J.C. Reed, Jr. and others (2005). U.S. Geological Survey Data Series 424 .
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
Instituto Nacional de Estadística, Geografía e Informática. Conjunto de Datos Vectoriales Geológicos. Continuo Nacional. Escala 1:1’000,000.
88 valid minerals.