The volcanogenic massive sulfide and sedimentary exhalative deposits of the Guerrero Terrane, Mexico.

Abstract

More than 60 volcanogenic massive sulfide and sedimentary exhalative deposits are located in the composite upper Jurassic-lower Cretaceous Guerrero terrane of western Mexico. The deposits range from less than 100,000 metric tons up to 6 million metric tons. Most of the deposits are Zn-Pb-Cu Kuroko type and are located within the Zihuatanejo and Teloloapan subterranes. The Guanajuato and Calmalli, Baja California, deposits are Zn-Cu. The Cu type Copper King, Guerrero, deposit is located in the Papanoa complex. Arroyo Seco, Michoacan, is the only Pb-type and can be classified as a sedimentary-exhalative deposit. The sulfides lenses have suffered metamorphism. The δ³⁴S values of Teloloapan deposits are mainly negative. The mean δ³⁴S values of the deposits of Zihuatanejo subterrane are mainly positive. Lead isotopic data suggest that the source of metals for the Zihuatanejo, Teloloapan and Huetamo Tertiary epigenetic deposits of the Guerrero terrane was a combination of metal sources e.g. the Mesozoic crust, the middle-Tertiary volcanic rocks, and the Sierra Madre Oriental. Guanajuato, Zacatecas, Fresnillo, and Real de Angeles districts are located at the suture zone between Guerrero terrane and Sierra Madre Oriental that could have provided channels for hydrothermal systems that extracted metals from different sources.