<title>Digital image processing for lithological and alteration mapping using SPOT multispectral data: a case study of Pariz area, Kerman Province, Iran</title>

Abstract

Tertiary porphyry deposits in Iran are an important source of Cu, Mo and locally Au. Most of the known porphyry Cu deposits are located in the Central Iranian Volcanic Belt(CIVB). Pariz area is located within this belt and is chosen as a test area to evaluate remote sensing data at one such area, and use of these data in exploration of the other parts of CIVB. Eight known mineralization sites were chosen in the area, which are mainly porphyry type. SPOT images in XS mode are used to study geology as well as hydrothermal alteration in the Pariz area, where soil and vegetation cover is substantially poor. Different approaches such as band ratioing, principal component analysis, I-S-H decorrelation processing, digital filtering and hybrid composite were used to enhance the diagnostic features associated with the lithologies as well as the hydrothermal alteration. Color combinations of the principal components, I-S-H transformation and 2/1 ratio have proved to be the best image enhancement techniques for geological studies in such areas. Lineament analysis has shown that the areas with known ore occurrence and the hydrothermally altered areas are closely associated with the higher photolineament factor values. Comparison of geophysical and remote sensing data has shown that there is a good correlation between the airborne geophysical and remote sensing data in the area.

The application of advanced space-borne thermal emission and reflection (ASTER) radiometer data in the detection of alteration in the Chadormalu paleocrater, Bafq region, Central Iran

“…orthoclase, albite, quartz). Ranjbar et al (2001) applied different approaches, such as band ratioing, principal component analysis, I-S-H (IntensitySaturation-Hue), decorrelation processing, digital filtering and hybrid composite to enhance the diagnostic features associated with different lithologies, as well as hydrothermal alteration minerals in the Pariz area, Central Iran. Beratan et al (1997) have applied ground, Landsat TM and AVIRIS data to the mapping of alteration.…”