The metallogenic evolution in Mexico during the Mesozoic, and its bearing in the Cordillera of Western North America

The above configuration of metallogenic events and provinces occurred in response to drastic changes in the general tectonomagmatic regime: from magmatism associated with Jurassic to Albian synvolcanic extensional unroofing (magmatic oceanic realm for ore deposits) to a contractional continental volcanic arc thereafter (magmatic continental-subaerial realm for ore deposits). The transition from these metallogenic magmatic realms occurred between the mid-Aptian and mid-Cenomanian, and Mexico represents the last region in the Cordillera of western North America in which such transition occurred-it was predated by similar processes in Alaska and Canada between the Lower Jurassic and the Middle-Upper Jurassic, and in the southwestern USA between the Middle-Upper Jurassic and the Lower Cretaceous. Such southward and cratonward (eastward) progression was accompanied by orogenic pulses, which overlap in NE Mexico as thin-skinned Sevier structures were followed by thick-skinned Laramide structures, and were largely controlled by flattening of the subducted slabs. Laramide orogenic pulses played a key role in the formation of orogenic gold deposits, but are also responsible for the mobilization of basinal brines that ultimately led to the formation of MVT and red-bed deposits, although several of such deposits might have formed earlier, and others are post-orogenic.