This page kindly sponsored by Peter Megaw
In a regional geological and mineralogical perspective, Santa Eulalia is the largest of a number of similar Carbonate Replacement Deposits that occur in a 2200 km long belt running from Hidalgo State to the Chihuahua-U.S.A. border…and into the USA (Megaw et al., 1988). This belt of deposits includes many of Mexico’s most prolific specimen-producing mines such as: Ojuela, Naica, Concepcion del Oro, Los Lamentos, San Carlos, San Pedro Corralitos, Charcas and Sabinas-San Martin. That these deposits are prolific specimen producers stems from aspects of their primary genesis and subsequent oxidation that create abundant open space during times when crystal growth potential is high. Additionally, the largest Carbonate Replacement Deposits characteristically underwent multiple stages or pulses of mineralization and oxidation, which results in mineralogical overprinting and the creation of a wide range of pseudomorphs. Santa Eulalia is especially well endowed in this regard.
The Sierra Santa Eulalia consists of Cretaceous carbonate and evaporite strata deformed into a broad, north-northwest-trending, doubly-plunging anticline with generally gentle dips. These rocks were subsequently deeply eroded and unconformably buried by a southward-thickening succession of early- and mid-Tertiary volcaniclastic and caldera-related volcanic rocks. Pre and intra-mineral intrusive dikes and sills are important ore localizers and mineralization is closely linked in time and space to distinctive felsite intrusions. Post-mineral faulting or deformation is minimal, so erosion and oxidation from meteoric waters is all that has happened to the ores since their deposition.
The mining district is divided into the West and East Camps, based on a combination of geography, production and style of mineralization. The West Camp (a.k.a. The Main Mineral Zone; Prescott, 1916 and Hewitt, 1968) lies on the western flank of the range and is characterized by massive sulfide manto and chimney orebodies with local, high-level iron-calcic skarns. The East Camp (a.k.a. the San Antonio mine area) lies on the eastern fringe of the range and is characterized by bilaterally symmetrically zoned, intrusion-cored skarns with peripheral massive sulfide manto bodies. The 2.5km wide intervening zone, known as the Middle Camp, contains minor mineralization and saw limited production, but is generally considered barren. The ultimate source of the district mineralization is actively being sought, but remains elusive.
Mineral ListMineral list contains entries from the region specified including sub-localities
184 entries listed. 149 valid minerals.
Localities in this Region
The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Prescott, 1916, AIME Transactions, Hewitt, 1943, 1968, AIME Transactions, Megaw and others, 1988, Economic Geology