Abstract The Zimapán Mining District. in the Zimapán municipality, western Hidalgo State. is located at geographic coordinates 20±47'N and 99±24'W. Access is by Federal Highway 85 (Mexico-Laredo) at m 207 (Fig. 1). Unpaved roadways lead from the village of Zimapán to the district's main mine areas at Carrizal, 7 km northwest. and E1 Monte, 8 km north (Fig. 2); Zimapán has all the basic services as well as a light-aircraft runway.

Abstract This study presents a regional structural analysis and a stratigraphic study in Hidalgo and Querétaro states, east-central Mexico, where strata of the Sierra Madre Oriental foreland fold-and-thrust belt are structurally juxtaposed against Middle (?) and Upper Jurassic back-arc sequences. Rocks of the San Juan de la Rosa Formation were apparently affected by major compressive deformation during the Early Cretaceous (Nevadian?) and Laramide orogenies. Toward the east, the style of deformation is that of a typical foreland fold-and-thrust belt, whose major thrust faults are located at the Zimapán Basin margins flanked by the El Doctor and Valles-San Luis Potosí carbonate platforms. Below the El Doctor thrust, at least seven thrust faults are exposed that crosscut the middle Cretaceous rocks and the enveloping Upper Jurassic-Lower Cretaceous and Upper Cretaceous marly shaly beds in the form of a duplex. The style of deformation between the two carbonate platforms is probably thin-skinned. Speculative, semibalanced cross sections indicate an average shortening between the Zimapán Basin margins of 39.4% of its initial width. Depth to the sole thrust is estimated to be about 2000 m below the present sea level.