Writers : Navai.Iraj and Mehdizadeh Tehrani .Simin
Refference : Geosciences Scientific Quarterly Journal,No.:13,P.:14
Publishing Year : 1373

Abstract :
From a review of existing literature, there seems to have been inadequate attention paid to date to the moduilty of the units of Quaternary alluvial deposits and their relationship to their source rocki. This study was carried out with the earn of attempting to demonstrate to the geological community the possibility of using satellite muhispectral data to bring to light certain aspect of this process.
For this purpose a 54 kmx50 Km. Subecen. of a cloud free Landsat TM Image acquired in 1990 of the area around P.afsanjan in south Iran was selected. The area in this subscene Is almost wholly covered by the 1:100,000 Map Produced by the Geological Survey of Iran in 1971. The analysis was carried out using the 6 bands digital `TM' data.
Of the various combinations attempted, the combination of TM bands 1,3 and 5 on the Red, Green and Blue was selected for optimum discrimination of geological deposits.
In this band combination, many lithologloal units were easily dIstinguishable from each ether. In the case of alluvial deposits it was most Interesting to note the alluvial material examined, exhibited almost exactly the same colour as the source rocks from Which they were derived. As a consequence, it was quite possible to differentiate the alluvial deposits according to their source.
The Importance of such capability Is of course most apparent in cases of minerals exploration. In other words by distinguishing the source, it would be possible to delineate an area of high concentration of minerals derived from a source in which that is present in a low.grade and in disseminated form. Example of such situations that Immediately come to mind are gold exploration In placer deposits and exploration for uranium minerals, whose solubility and subsequent redeposition in alluvial deposits makes them ideal for such a technique.
Furthermore, with view to the possibility of distinguishing such surface deposits, the utilization of such technique for exploration of building materials, specially those without the presence of undesirable, contaminants such as cypsum or salt, becomes a necessity.
Subject List : Alluvial deposites