MINERAL PATTERN IDENTIFICATION AT TWO HYDROTHERMAL AREAS USING ASTER DATA

Minerals resulting from hydrothermal alteration are important indicators of processes occurring at and below the Earth's surface. Remote sensing data has increased the practicality of identifying spatial patterns of mineral types and compositions at the Earth's surface, and to use these patterns to investigate active and past near-surface processes. In this study, we have used ASTER data to search for hydrothermal mineral assemblages in two areas: Mickey Hot Springs, in the Alvord Basin of southeast Oregon, and Leach Hot Springs, in Grass Valley, Nevada. ASTER data was used in combination with published data on fault locations and orientations search for evidence that the active zones of hydrothermal discharge in the two areas have migrated over time, indicating a time-sequence of evolution in the faults controlling the surface expressions of the respective springs. The identification of these types of spatial correlations in mineral distributions may be useful in future studies of hydrothermal system evolution in fault-controlled systems.