evaluation of accuracy lineament extraction from satellite image for mineral exploration at Tarom region, Zanjan

One of the common used of the remote sensing in mineral exploration is applying the landsat and Aster satellite image in order to extract tectonic lineaments. In the current study, as well as analyzed the RS data and lineament extracted by the these satellite image and comparing with field data, result indicated in the small region the lineament extracted from satellite image attitude are discordance with filed data result, and are not applicable in detailed mineral exploration . Since in satellite image cannot distinguish and separate between ridges and valley lines and also roads and fractures from tectonic lineaments. The mentioned problem is obvious in all image, but it is about 50% lower in landSAT 8 pictures in comparison with aster. The study region is located at Tarom area, Zanjan, Iran, which is target for exploration of copper ore deposite, for many years. The field investigations and analyzing the resulted samples shown development of the poly metallic ore deposit in this region, which have been created due to tectono-magmatic process. Scientific findings indicated, this types of ore deposits are affected by mineral substitution in fractural systems due to expansions, contractions and tectonic tensions. Our investigation revealed identification of fracture pattern have an important role to exploaration of ore deposits in the region. In order to have a better insight, 370 samples for fracture have been taken from 3 various stations within 85 m2 area, in a region with an area about 40 km2, and the yield data were analyzed and after exerting the required filters, the resulted rose diagram have been compared with the diagrams derived from satellite image and also the lithologic and tectonic structures of thin sections. The results have shown the large amount of disagreement between the satellite images derived diagrams and the combined data results. On the base of landsat 8 satellite pictures, the explored lineaments are divided to 2 main groups with a dominant directions N025E and N045E, but the field investigations have depicted that the dominant direction of fractures are N12.5E, N7.5E and N17.5E. as a result these types of satellite image may not be preferred to be used for the mentioned aim at large scales.