DETERMINING THE CRITICAL MINERAL POTENTIAL OF THE WICHITA MOUNTAINS

The Wichita Mountains of Southern Oklahoma consist of knobs and hills exposing Cambrian to Proterozoic age igneous bodies and Cambrian to Ordovician carbonate and shale, surrounded by Pennsylvanian age primarily clastic sedimentary basin units fed by proximal erosion of the range. Deeper mafic units are abundant as well, as found in local outcrops and highlighted by steep magnetic intensity gradients in USGS airborne geophysics. Many of these units are enriched in the critical minerals found in the USGS’s Earth-MRI database, though the precise mechanisms and distribution of this mineralization is uncertain. Working with the USGS Earth-MRI program, the Oklahoma Geological Survey (OGS) is conducting new and compilation mapping across eight 7.5’ quadrangles across the Wichitas. Conducting such work can be perceived as exploration for resource extraction, causing consequent environmental impact. Apache, Chickasaw, Caddo, Comanche, and Kiowa nations make up much of the community in the region, and therefore OGS worked with experts in tribal engagement to better understand the nature of these tribal areas and build communications with tribal leaders. Additionally, much of the region comprises military installations and wilderness areas, requiring multiple levels of communication. Our message was that the project is to explain the fundamental scientific nature and support a broad national assessment mission – as opposed to mineral exploration – to the stewards of these areas, with all data provided to the public which will in turn benefit local stakeholders. Along with the geologic mapping schema (GeMS) Level 3 and final GeoPDF map products, data released will include bulk-rock geochemical analysis from up to 200 samples. We also collect data with a hand-held X-ray fluorescence (XRF) device. Elemental data include titanium enrichment in mafic dikes associated with the GMLC. Pegmatite-aplite features observed in the Quanah, Lugert, and Reformatory Granites show a more evolved composition than the host granites, increasing the likelihood of economic critical mineral potential. Future work will focus on timing and mechanisms of critical mineral paragenesis within previously mined areas and throughout the broader region impacted by igneous and hydrothermal processes, as well as sedimentary recycling.