This metallogenic province covers 420,880 km2 (Salas, 190, p. 69–77) and coincides with the huge Mexican Geosyncline, a miogeosyncline extending from Alaska through the western United States and crossing the Mexican border in the vicinity of Ciudad Juarez (Chihuahua) to form the Sierra Madre Oriental.
The Sierra is a chain of elongated mountains formed by large synclines in Jurassic and middle Cretaceous limestones and intercalated clastic sedimentary rocks several thousand meters thick; in some areas (Cañon del Novillo, west of Ciudad Victoria,Tamaulipas) the Mesozoic section is unconformable over Precambrian metamorphic rocks, schists, and gneisses. Figure 1 shows the extent of the province, interrupted at its southern end by the Neo-Volcanic Axis, as seen on the ERTS-1 Satellite image mosaic.
The large folds and faults in Mesozoic limestones trend generally northwest except between Torreon (Coahuila) and Monterrey (Nuevo León) where the Great Mexican Geosyncline deviates at the southern end of the Coahuila paleopeninsula and structures are almost east-west. The hinge of this deviation, trending east-west to northwest, and the Tertiary intrusives, coincide with the Concepcion del Oro Mining District (Zacatecas).
Figures & Tables
Economic Geology, Mexico
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.