Técnicas de procesamiento de imágenes en la exploración de yacimientos minerales de origen hidrotermal.

Abstract

Satellite images were used to identify aseas with hydrotherzna]ly altered rocks that may be related with epithermal mineral deposits. A TM image from an area located in the westem border of the Mexican Volcanic Belt that hosts precious metals and opal deposits. The mineralization is the result of dic hydrothermal activity linked with the Física de la Tierra, 7,105-137. Servicio de Publicaciones. Universidad Complutense, 1995 nfr 106 J. R. Ruiz-A rtnenta R. M. Pral-Ledesma y processes that formed the Sierra Madre Occidental during the Tertiary. Topographic features make exploration difficult, and the use of satellite images is necessary to establish target areas for detailed mapping. Samples were collected to characterize arcas with hydrothermal alteration, and the localities were used as control points to evaluate the results from the processing of the TM image. Principal components analysis was used in the image processing in order to differentiate the areas that contain hydrothermally altered rocks from arcas covered with different types of vegetation that do not contain rocks with hydrothermal alteration minerals or their weathering products. The comparison of the resulis obtained after the processing of the TM ituage with the data collected in the fleld yielded a good correlation. AII the control points weic identified in the processed images. and the erroneous identification of crop fields and young lava flows in the early stages of processing was avoided in the last stage wit.h the overlay of the images where oxide atid hydroxyls `vete highlighted.