Abstract The mineralogy of a leach cap over a subeconomic Mo-Cu porphyry deposit in the Grizzly Peak caldera in the central Colorado Rocky Mountains provides evidence of mineralization and indications of natural acid drainage potential. Airborne hyperspectral imaging (HSI) remote sensing is used to construct a spatially complete map of the leach-cap iron and clay minerals within the mineralized, acid-generating alteration zone. The mixtures of jarosite, goethite, and hematite provide direct indications of mineralization and acid source locations. The clay minerals illite (sericite), kaolinite, dickite, and pyrophyllite further characterize the alteration and appear to correlate with acid seeps. The illite chemistry is analyzed by mapping chemical substitutions of iron for aluminum and is highly correlated with acid sources. When integrated with mapped and interpreted structures, the controls on the acid drainage are revealed.

Abstract The Colorado Geological Survey is a participant in the Southwest Regional Partnership on Carbon Sequestration project. The primary goal of the project is to determine an optimum strategy for minimizing greenhouse gas intensity in the southwestern United States. The Southwest Regional Partnership is led by the New Mexico Institute of Mining and Technology and comprises a large diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. In 2000, carbon dioxide (CO 2 ) emissions in Colorado exceeded 83.5 mmt (92 million tons) and are projected to increase by 2.4% per year through 2025. Nearly 76% of these emissions results from activities in the utility and transportation sectors. Power generation in the state relies primarily on coal, and as a result, 38 mmt (42 million tons) of CO 2 , or 46% of the total emissions in Colorado, is emitted from power plants in the utility sector. These stationary point sources afford the possibility of capture and separation of CO 2 for transport to and storage at nearby sinks. The remaining 54% of Colorado’s emissions result from the transportation, industrial, residential, and commercial sectors. Although CO 2 sink potential is widely distributed across the state, characterization efforts focused on seven pilot study regions defined on the basis of maximum diversity in potential sequestration options relatively close to large CO 2 sources. Using both geologic and mineralization options, carbon storage capacity within these regions is an estimated 653 billion t (720 billion tons). With the availability of suitable technology, the pilot areas have the potential of providing a long-term storage solution based on 2000 CO 2 emission levels. The highest CO 2 sequestration capacity potential for Colorado lies within the oil, gas, coalbed, and saline aquifer reservoirs of the Denver, Cañon City, Piceance, and Sand Wash basins. Further site-specific investigations are required to determine both the technical and economic feasibility of implementing carbon storage projects in any one of these areas.