San Martín Mine, San Martín-Sabinas District, San Martín, Mun. de Sombrerete, Zacatecas, Mexico
|Latitude & Longitude (WGS84):||23° 39' 48'' North , 103° 44' 45'' West|
|Latitude & Longitude (decimal):||23.66333,-103.74583|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
|Name(s) in local language(s):||Mina San Martin|
The San Martin Mine was operated by Grupo Mexico until the late 2000s when it closed due to labor unrest. It remains closed as of today (2012). The San Martin Mine exploits the southeastern part of the same skarn orebody actively exploited by Industrias Penoles through their Sabinas Mine. The property boundary between the two companies dovetails irregularly through the western part of the skarn body and the mineralogy is essentially identical on both sides of the boundary so there is no geological difference between the two mines. However, the San Martin Mine got started going deep 25 years before Sabinas so was operating at much deeper levels at any given time. This means minerals characteristic of the upper levels of the system (apophyllite, stilbite, stibnite) came out of Sabinas 20 years or so after they came out of San Martin. Since San Martin closed in the late 2000s all specimens from the district have come from Sabinas.
Most of the minerals seen from San Martin are primary species, but oxidation affected the deposit from the surface to about the 150 m level. Most of the oxides were mined out long ago, but small prospect and high-grade pits dot the surface and oxide minerals can be found there. These oxide minerals reflect their sulfide precursors with chrysocolla and azurite seen around the peripheries and adamite and conichalcite and cerussite towards the intrusive contact.
Prior to 1948 the San Martin Mine exploited narrow high-grade veins that cut the skarn and extend beyond it. These structures continue to depth and appear to be the principal feeders for the sulfide mineralization stage. At great depth (>18 Level) these structures contain massive sulfide mineralizaation consisting of almost pure chalcopyrite and bornite, locally laced by late native silver. They can also be traced upwards to the top of Cerro La Gloria where they show classic epithermal brecciation and mineralization textures such as quartz pseudomorphs after bladed calcite. Some of these mines produced some of the richest silver ores ever produced in Mexico outisde of Batopilas and the district was recognized as the source of the wealth that allowed Mexico to free itself from Spanish rule in the early 1800s.
Many specimens from the Sabinas Mine and probably San Martin as well bear an erroneous "Noria Mine" or "La Noria de San Pantaleon" label, often from Blue Sky Minerals, which brought out a lot of material from the district in the 90s. Specimens younger than 1975 cannot have come from La Noria and since the Sabinas Shaft and Ramp lie over a kilometer from the Noria Shaft and the Sabinas mine workings have never been accessible through the Noria workings there is no justification for labeling them as Noria. La Noria de San Pantaleon was the small mine colony at the headframe of the Noria Mine. This settlement shows on government maps but was largely abandoned by the 1980s. in 1999 there were only one or two habitable buildings left. If one desires a nearby community for location attribution "San Martin" which is the miners town of several hundred people 2 kilometers from the Sabinas installations,is a better choice than San Pantaleon.
28 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
66 - 100.5 Ma