AN INTEGRATED GEOLOGIC AND GEOPHYSICS APPROACH TO MINERAL POTENTIAL MAPPING OF CLIMAX-TYPE PORPHYRY MO MINERALIZATION IN COLORADO

An overview of the Climax-type (high-F) porphyry Mo genetic model is presented with special consideration given to the spatial representation of mineral system components from the deep to shallow crust and their mappable expressions. This information was used to build spatial-conceptual predictor maps of the Climax-type mineral system in Colorado, which is host to three world class Climax-type deposits and a resulting mineral potential map. Unlike data-driven models which require training data (i.e., mineral occurrences), conceptual-driven models do not rely on training data and may be applied with little to no adjustment. Spatial-conceptual predictor maps were created from mapped geology, interpreted deep geology, interpreted tectonic domains, interpreted hydrothermal alteration from hyperspectral ASTER satellite data, crustal depth from EarthScope USArray data, gravity data, and magnetic data. A key component of the mineral potential model was the use of multiscale magnetic edge data to act as a proxy for structural and lithological elements of the Climax-type mineral system at a range of vertical scales and in areas of unfavorable cover lithology.

The resulting mineral potential map highlights areas of known Climax-type and Mo mineralization and other areas that meet all the spatial-conceptual criteria for Climax-type deposits, including areas of known Au-Ag, Cu, and Pb-Zn mineralization. The mineral potential model emphasizes a strong spatial relationship between Tertiary Climax-type mineralization and Precambrian basement domain boundaries, particularly where they are intersected by Late Cretaceous-Tertiary Laramide-associated structures, the edge of the Tertiary Rio Grande Rift, or San Juan volcanic field calderas. Presumably, structures and metamorphic or rheologic contrasts at major Precambrian domain boundaries and intersecting younger structures increased bulk crustal permeability relative to surrounding rock permitting melts to preferentially travel and evolve from the deep to the shallow crust. This relationship suggests that a first-order deep to shallow crustal plumbing system is an important factor in the formation of Climax-type porphyry deposits, particularly where major plumbing systems overlap.