Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Results of the Remote Sensing Studies and Reasons of Composite Halos in Exploration Kahang Area

Document Type : Original Research Paper

Authors
A. Khakzad 1
A. Khakzad 2
H. Asadi 3
M. H. Emami 4
1 North Tehran Branch, Islamic Azad University, Tehran, Iran
2 Faculty of Engineering, Industrial University of Esfehan, Esfehan, Iran
3 Faculty of Engineering, Industrial University of Esfehan, Esfehan, Iran.
4 Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran.
10.22071/gsj.2012.53977
Abstract
Kahang exploration area located in Esfahan state and 10 Km of the east of Zefreh town that is located on Uromieh-Dokhtar volcanoplotonic belt. Primary results showed that it has good potential for resources of Copper (Cu) and Molybdenum (Mo). Kahang region is an alteration and breccia zone. Generally, more than %90 of rocks of this region has been affected by hydrothermal fluids.The occurrence of altration zones and Iron Oxides were confirmed by Satellite images processing. Faults and linear features were recognized using Satellite images (ETM) processing and PCA method. 320 litho geochemical samples of the area have been collected. They were chemically analyzed For geochemical survey . For the reason of irregular distribution of the elements in haloes related to porphyric massives , the normal data are used for study of distribution pattern of indicator elements and drawing maps . Also , the degree of correlation between elements are calculated using some statistic methods such as spearman and pearson and cluster analysis .Based on factor analysis method is distinguished that principal elements of the area are affected by 4 factors. In the next stage , geochemical maps of unielement of soil and rock samples are drawed for study of pattern of zonation of elements . Based on threshold limit method , the anomalous areas and pattern of zonation of elements are distinguished. Also, for separating and identifying the important anomalies, the P.N. method was used. For investigation of geochemical behaviors of Cu and Mo, anomalous maps of 10 elements were drawn which are Cu, Mo, Au, Ag, Pb, Zn, As, Sb, Mn and Ba. Consequently, it was found that in central part of Quartzmonzonites and Diorites areas the most concentration of Cu and Mo have been occurred, whereas in the margin of the andesitic rocks areas there is the most concentration of supergeous ores such as Pb, Zn and Ag.
To get better results and also to select the proper points for drilling, the composites haloes method was used and on the base of standard normalized data, the map of composite haloes of supergene and hypogen ores were drawn. The Solovof method was used for evaluation of erosion surface in ore area. The results show that the ore is located in subsurface and has not been destroyed by erosion.
Keywords
Copper and molybdenum porphyry deposit
Remote Sensing
Alteration halos
Geochemistry halos
Composite halos
Kahang
References
Barnes, H. L., 1979- Geochemistry Of Hydrothermal Ore Deposits, second  ed., 798p.
Kariuki, P. C., Woldai, T. & Meer van der, F. 2004- The role of Remote Sensing in Mapping Swelling Soils. Journal of Geo-information Science and Earth Observation, vol.5, No.1.
Middlemost, E. A. K., 1994- Naming Materials in the magma , igneous rock system p. 215-224                                                                                             
Rose, A. M. & Burt, D. M., 1979- Hydrothermal Alteration, p. 173-235                 
Sillitoe, R. H., 1983- Enargite- bearing massive sulfide deposits high in porphyry copper system: Economic Geology, p. 348-352                                         
Sillitoe, R. H., 2003- Linkages between volcano tectonic setting, ore-fluid compositions, and epithermal precious-metal deposits, p.315-343
Scientific Quarterly Journal of Geosciences
Volume 21, Issue 84
Autumn 2012
Pages 161-168