Application of remote sensing techniques in alluvial sampling design for exploration of placer deposits in the semi-arid areas
Abdul Hamid Amiri
Assistant Professor, Department of Geology, Islamic Azad University of Shiraz, Iran,
E-mail: amirihamid@yahoo.com
Hojjatollah Ranjbar
, Associate Professor, Department of Mining Engineering, Shahid Bahonar University of Kerman, Ker,man, Iran.
E-mail: h.ranjbar@mail.uk.ac.ir
Mehdi Honarmand
Kerman office of industries and mines, Kerman, Iran
E-mail: mehdihonarmand167@yahoo.com
Abstract
Alluvial sediments are important for exploration of gold, diamond, ilmenite, etc. It is important to search for such kind of deposits by using ground sampling. The important question is that, where to collect samples? One has to have a comprehensive knowledge of the regional geology, the type of expected source rocks, the geomorphic and climatic factor and the type of deposits considered for exploration. By refereeing to the geological maps, one can not classify the alluvial deposits based on their source rocks. They are usually classified according to their type (silt, clay, gravel, sand etc.) or according to their age (quaternary, Recent etc.). As the alluvial deposits are composed of different assemblages of minerals, it is possible to map the alluvial deposits based on their source lithologies by using multispectral satellite images. In the arid and semi-arid types of climate it is much easier to separate different alluvial deposits according to their source lithologies. In this study Both ASTER and ETM+ data are used to show that the source lithologies and the spatial distribution of their alluvial deposits can be clearly mapped by different image processing techniques. Once this is done, the sampling design should be very cost effective. Shahre-e-Babak and Kahnouj areas which are located in Kerman province in Iran are chosen as test areas to show the capability of remote sensing technique for the exploration of alluvial deposits.
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