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Author: Laura Margaret Brady 520 North Park Ave Phone: (520) 930 4040 A process for integrating remote sensing and spatial data analysis to accurately map and monitor small-scale to medium-scale mining in a semiarid climate within Patagonia and southern Santa Rita Mountains is described. Areas selected for this study include the drainage basins for Harshaw Creek, Flux Canyon, Humboldt Canyon, and the Sonoita Creek. Numerous mines, prospects, waste dumps, and tailing piles are abandoned within these basins, but large parts of the region are mineralized and remain largely undisturbed. Altered but unmined exposures contain extensive quart-sericite-pyrite and clay alteration zones. Maps of soils, sediments, water, and vegetation effects can be used as input into a model that accounts for the identification of dispersion features of waste piles and erosion of mineralized rock and soils in mountainous watersheds. Water is an important and incredibly valuable resource in this area. This issue is exemplified by problems associated with CERCLA in efforts to provide cleanup to degraded areas. Sites of degraded water (low pH, elevated metals) are coincident and influenced by man-made and natural processes. However, distinct enhancements in contaminant levels in water and sediments are indicated where recent rock exposure has been cleared and subsequently eroded. The variances in anthropocentric effects are currently undefined. This study will attempt to identify the chemical composition and variance within several watershed components to compare with man-made alterations. A watershed scale erosion model in GIS is used to estimate sediment yield from four separate watershed systems. The model results will provide insight into the point and nonpoint causes and sources of sediment yield to the drainage system. Several alternative ways the pattern could be used to develop mitigation strategies are discussed. |
