El Oro, Mexico
History
Mining
| 1529 | First records of mining was by Spanish in the Borda Coronas Area |
| 1700s | Cornish Tin miners arrive in El Oro and restart mining of the Spanish discoveries |
| 1880s - 1929 | El Oro Bonanza Mining Period: El Oro Mining, Esperanza Mining, Mexican Mining discover and mine the San Rafael Vein & others |
1900 |
Dos Estrellas Mining Co drives adit and discovers Veta Verde |
1929 |
San Rafael mine floods and production stopped |
| 1929 - 1938 | Dos Estrellas Mining Co. continues to mine Veta Verde, bankrupt in 1938 following a tailings dam slide |
| 1938 - 1959 | Mexican government hands over the district to the Workers Cooperative. Mining of backfill and pillars continued until 1959 on an ad hoc basis with processing plant located in Borda /Coronas area. Production appears to be minimal but no records exist |
Exploration
| 1969 - 1971 | More Mines Limited; Drilling Total: 2 holes, 513m - no results kept |
| 1983 - 1990 | Luismin drilled the surrounding areas for new veins 33 drill holes / 7064m completed with the Buen Despacho, Zona Oriente. Cortaduras, San Francisco de Reyes, Pomoca targets tested |
| 1993 | Hillsborough - San Rafael remnant resource definition drilling Total of 12 drill holes / 3008m |
| 1996 - 1997 | Teck - IP Geophysical Survey and Geochemical Surface Sampling Program - Veta San Rafael & Verde, Zona Oriente Drilling of IP targets mostly identified dykes not veins: 13 drill holes, 3069 m - Veta Verde, Zona Oriente, Cortaduras targets tested |
| 2003 - 2004 | Placer Dome - San Rafael Vein Drilling Total: 11 drill holes, 5021m Geochemical Surface Sampling Program Oriente |
| 2007 | Minera CCM S.A. de C.V. (Candente) Geophysical Program: Resistivity NASTM Regional Geochemical sampling Drilled 4096m in 11 holes underneath old mine workings in four veins: 8 holes hit targets and 7 mineralized structures intersected |