Tectonic and Metallogenetic History of Mexico

Abstract

Mexico is widely known to be a richly endowed country in both metallic and industrial mineral deposits, the exploitation of which has constituted an economic activity of paramount importance for centuries. This paper presents an analysis of the time and space distribution of over 200 mineral deposits, which is based on the available absolute and relative ages of mineralization and constitutes a modified and updated version of the analysis of Camprubí (2009). Pre-Jurassic ore deposits are relatively scarce and of subordinate economic significance. These include Ti-bearing anorthosites and rare element pegmatites in intracratonic environments, barite sedi-mentary-exhalative (sedex) deposits, and ultramafic-mafic Cr-Cu-Ni(-platinum group element [PGE]) deposits in oceanic environments. Since the Jurassic, the metallogenic evolution of Mexico can be understood as a product of the evolution of two major regions: the Pacific margin and the Gulf of Mexico. The Mesozoic evolution of the Pacific margin is characterized by rifting and separation of the Guerrero composite terrane from the North American continent and the initiation of arc magmatism in an extensional continental margin setting. The ore deposits emplaced in this period are mostly polymetallic volcanogenic massive sulfide (VMS) and Cr-Cu-Ni(-PGE) deposits associated with ultramafic-mafic complexes. These occur dominantly near the boundaries of the Guerrero composite terrane. Porphyry-type deposits emplaced in the mid-Cretaceous are subordinate and, apparently, small. These likely formed in island arcs that were later accreted to the mainland.