Identification of hydrothermal mineralization in Baja California, Mexico from orbit using the Shuttle multispectral infrared radiometer

Data from the Space Shuttle Multispectral IR Radiometer (SMIRR), which is a 10-channel remote sensor designed to record narrow band spectral data in the 0.5-2.4 micron wavelength range, were used to identify and study a previously unreported area of hydrothermal alteration on the Baja California peninsula. Absorption at 2.17 microns, which is diagnostic of the minerals pyrophyllite, dickite, and alunite, was observed in many spectra and the presence of pyrophyllite and dickite was confirmed by X-ray diffraction analysis of field samples. Anomalously high Mo, B, Sn, Zr, and Ag were found in three samples.