Himalayan-like Crustal Melting and Differentiation in the Southern North American Cordilleran Anatectic Belt during the Laramide Orogeny: Coyote Mountains, Arizona.

This article focuses on the petrogenesis and metamorphic history of the Pan Tak Granite in the Coyote Mountains, southern Arizona, as a representative of the North American Cordilleran Anatectic Belt formed during the Laramide orogeny (c. 80–40 Ma). Detailed geochemical, isotopic, and zircon petrochronological analyses reveal a three-stage crystallization sequence from 62 to 42 Ma involving prograde metamorphism and melt generation, peak metamorphism with zircon dissolution (53–51 Ma), and subsequent cooling and fractional crystallization producing two-mica granite and leucogranite phases. The Pan Tak Granite formed by fluid-deficient melting of meta-igneous Jurassic and Proterozoic source rocks, with heat supplied by radiogenic decay following crustal thickening, heat transfer from the Laramide continental arc, and deformation-related shear and viscous heating. These findings highlight the similarity between this Cordilleran anatectic belt and the Himalayan leucogranite belt, suggesting that thickened, low-relief orogenic plateaus with high heat flow and limited erosion are key environments for prolonged crustal melting in Cordilleran orogens.