La Negra Mine is located in the Maconí Mining District, Querétaro State, in the eastern part of the Sierra Guanajuato Gorda (Fig. 1). The nearest important town is Querétaro, 215 km southwest of the mine unit; the nearest village is Maconí, 5 km away from the mine. Access to La Negra Mine is from Querétaro on the Cadereyta-Maconi road, which takes about 2 hours. The nearest railroad station is San Nicolás, 120 km away on the México-Querétaro railroad. The mine is at an elevation of 2,000 m.
This summary is based mostly on work by José E. Gaytán- Rueda (1975), presently the Director of Peñoles Group Exploration-Mines; the Special Studies group of Industrias Peñoles, S. A., Exploration Division; and unpublished reports by the unit's Geological Department.
Figures & Tables
This volume was developed, produced, and privately printed in Mexico, in Spanish, by the late Ing. G.P. Salas in 1988, as a Mexican contribution to the Geology of North America, with the understanding that it would be translated into English for inclusion in the set. The translation is by Dr. Cecily Petzall of Caracas, Venezuela, with considerable figure translation and redrafting provided by GSA. Salas worked on the volume until his death, with much valuable help from Ing. Hugo Cortez Guzmán. The result is a valuable English-language synthesis of the information available to Salas in the early to mid-1980s about the geothermal, coal, and metal-mining sectors (and some non-metallic resources) of the economic geology of Mexico.