2002 Denver Annual Meeting (October 27-30, 2002)

Paper No. 13
Presentation Time: 4:40 PM

APPLICATION OF HIGH-ALTITUDE INFRARED SPECTRAL DATA IN HYDROTHERMAL ALTERATION MAPPING AND INTERPRETATION, NORTHERN PATAGONIA MOUNTAINS, ARIZONA


BERGER, Byron R., KING, Trude V.V., MORATH, Laurie C. and PHILLIPS, Jeffrey D., U.S. Geol Survey, Federal Center MS964, Denver, CO 80225-0046, bberger@usgs.gov

Data from NASA’s AVIRIS (Airborne Visible Infrared Imaging Spectrometer) sensor were used to map the spatial distribution of hydrothermal minerals in the northern Patagonia Mountains, Arizona. Integration with geologic and potential field geophysical data allowed the rapid delineation of hydrothermal alteration and mapping of alteration assemblages and mineral zoning patterns. Large areas of advanced-argillic, argillic, and phyllic alteration occur in the study area as well as several porphyry-style copper deposits, copper-gold veins, and polymetallic veins and replacement deposits. Three published hydrothermal alteration studies derived from field and laboratory data allow comparison of the AVIRIS sensor data to these more traditional approaches to alteration assemblage mapping and target delineation. One of these was conducted above the unexposed Red Mountain porphyry copper deposit and two studies were above the unexposed Sunnyside porphyry copper deposit. The high-altitude AVIRIS data yield lateral and vertical alteration zoning patterns comparable to the more traditional methods of study, provide a better mapping of the spatial distribution of advanced-argillic mineral assemblages, and are superior to traditional field methods in respect to the rapidity with which alteration mapping and interpretation can be accomplished. Conditions that limit the mapping capabilities of the AVIRIS sensor include dense vegetation, deep shadows, and cloud cover.