The Kalatereshm is an area in north of Iran which covers some part of Torud magmatic belt. The area of this belt is about 2000 square kilometers and most of the mines in this particular area are of Copper, lead and Zinc. The Synthesis process is done by the Analysis Hierarchy Process (AHP) and Index Overlay (IO) methods. Of previous studies on the area, various companies providing Geological maps and in particular the company of Jiangxi providing its own geochemical maps can be mentioned. The reasons for doing this research and its innovation in Kalatereshm’s sheet can be justified as to be valuable and the fact that we would be able to save in time and cost by doing so. Previous case studies on this particular region lacked the necessary use of an advanced software and method. The informational layers included geochemical layers (the second and first ratings were given to Copper and Lead respectively by weighting based on AHP method), geology layer (the fourth and second ratings were given to Copper and Lead respectively by weighing based on AHP method), fault layer (the first and fourth ratings were given to Copper and Lead respectively by weighting based on AHP method), satellite imagery layer (the third rating was given to both Copper and Lead by weighting based on AHP method) and the more applicable areas for field exploration and detailed procedures of exploration had been determined (the mentioned ratings were delineated by each element’s respective weight in each layer and their importance in the Synthesis of informational layers).
Mineral prospectivity analysis and quantitative resource estimation have been recognized as important when integrating multi-source geology spatial data in recent years. The statistical and mathematical approaches developed recently for multi-resource geological spatial data integration include Weights-of-Evidence (WoE) and logistic regression [
Mineral prospectivity modeling seeks to delineate areas that are likely to hosts mineralized zones. This is accomplished through the process recognition criteria, creating maps of this recognition criterion (predictor maps) and weighting and combining these maps to produce the final prospectivity map [
Integration with other specialized program for Geophysical data and image processing is easily done with GIS. Raster images, such as Satellite imagery or Geophysical images can then be displayed in GIS and overlaid with vector data such as Geology, Faults and Geochemical samples. Mineral targeting can be done based on multi evidence maps analysis, either using qualitative or quantitative methods [
GIS has the potential for storing, updating, retrieving, displaying, processing, analyzing and integrating various geospatial data [
GIS can produce mineral potential maps easily and integrates the results of different investigations such as Geological, Geophysical and Geochemical studies [
Mineral deposits are extraordinary anomalies in the earth that provide us with perhaps the clearest evidence for the past flow of solutions through faults, fractures and porous rocks that, in the process, dissolved, transported and concentrated elements of economic interest [
The past quarter century has been major advances in the understanding of the genesis Mississippi-Valley- Type (MVT) Lead-Zinc deposits. Until the early 1980s many workers believed that plate tectonics played no direct role and that MVT mineralization required little more than the presence of platform carbonates. Recent studies have shown instead that most (though not all) MVT deposits were produced by enormous fluid systems that migrate thorough foreland basins, driven by gravity from an adjacent orogenic belt (e.g. Graven, 1985; Ge and Graven, 1992; Appold and Graven, 1999; Leach et al., 2001a) [
The purpose of this research is to provide potential maps from Lead and Copper applicable areas which are done by the synthesis of informational layers that illustrates areas which have potential for advanced exploration.
The Kalatereshm’s 1:100,000 geological sheet is located on the 54˚ to 54˚30' eastern longitude and on the 35˚ to 35˚30' northern latitude. The area is about 2500 square kilometers. This region is located in south of Damghan and east of Semnan, and covers the southwest part of Torud 1:250,000 sheet (
A Geological map has been published by the national oil company of Iran which is in scale of 1:100,000. The 1:250,000 map has been provided by the Geology organization of Iran by M. Alavinaeini et al., in the year of 1978. From the two mentioned maps, one can find the overall Geology information, the process of outcrop, the structural elements and the position of the area being analyzed in the structural zones. The map of Torud in 1:250,000 scale has been provided by the M. Alavinaeini et al., and its associated report has been done by A. Hooshmandzade and et al. and has been published by the Geology organization of Iran. Reyre and Mohafez
have done some researches on the Sedimentary basin of this area in 1972 which also includes the Chah-shirin. Urdea and Melak poor have done researches on the Lead and Copper distribution in the area of Kalatereshm. Some researches have also been done in the department of mines and metals of Semnan which have been produced by the prospector engineers in the year of 2001 in the entire of Semnan Province and the private sectors have also done some researches on the diverse minerals on the area. Providing 33 geological maps from the stream samples by the Chinese company of Geochemical and Geophysical (Jiangxi) in the year of 1995 in the 1:100,000 sheet of the Kalatereshm (Geological Survey of Iran).
Eocene-oligocene Pyroclastic Igneous and Sedimentary rock units have a great diversity in the Kalatereshm sheet’s range, as they cover most of the northern half. This Tertiary Volcanic-sedimentary series covers the older units in the process of unconformity. The thickness of this complex can be estimated to be around 3 kilometers.
Based on the Geochemical and Petrography studies on Igneous rocks of this region, they are considered to be intermediate Igneous rocks which mostly include Andesite, Basalt andesite, Trachy-andesite, Dacite and Ryolite.
Based on the Petrographic studies done on these rocks it is clear that they have undergone a very weak alteration (Green schist facies). In this alteration, the fluid pressure and temperature have played an important role. These alterations have caused the high mobility elements to be displaced which from these processes include Argillitic transformation and Carbonatization and etc which have caused to rocks to be positioned at the range between Alkaline and Sub-alkaline.
In this article, each of informational layers (Geological layer, geochemical layer, Fault layer and Satellite imagery layer) has been integrated based on their priority. The integration of these informational layers has been done using the Arc GIS software by Index Overlay Modeling and the evaluation of these informational layers has been done in the Expert Choice software. Weight of Evidence in contrast uses the statical analysis of the map layers being used with a training data to make less subjective decisions on how the map layers in any model are combined. Bonham-Carter (1997) gives a good summary of the maths and algorithms used in Weights of Evidence and Partington (2000), Partington and Smillie (2002) and Rattenbury and Partington (2003) give examples of how this technique can be applied to geological datasets [