Remote sensing and Aeromagnetic investigations in porphyry copper deposits for identification of areas with high concentration of gold: a case study from the central part of Dehaj-Sarduiyeh belt, Kerman, Iran

Document Type : Research Article

Authors

• Mahdieh Hosseinjani Zadeh
• Mehdi Honarmand

Graduate University of Advanced Technology

10.22067/econg.v10i1.53510

Abstract

Introduction
Remote sensing has shown tremendous potential in the identification of alteration zones. The importance of this science for mineral exploration and recognition of alteration zones with lower cost, time, and manpower is confirmed in many studies (Amer et al., 2012; Hosseinjani Zadeh et al., 2014; Tayebi and Tangestani, 2015; Shahriari et al., 2015). Gold is one of the byproducts in most of the porphyry copper deposits (PCDs). Although the gold assay is partly low and reaches between 0.012- 0.38 g/t in these deposits, the high tonnage of copper deposits provides a considerable source of gold which has an important economic value (Kerrich et al., 2000). Extension, intensity of alteration, assays and the type of mineralization vary in different deposits. For instance, many Au-poor porphyry copper deposits in southwest USA, Central Asia, and west of South America are associated with widespread phyllic alteration (Kesler et al., 2002). In addition, there is a positive correlation between gold and magnetite in PCDs (Kesler et al., 2002; Shafiei and Shahabpour, 2008; Sillitoe, 1979). Therefore, aeromagnetic investigation could be useful in identification of these deposits. The aim of this research is discrimination of alteration zones and investigation areas with high concentration of gold through processing of remote sensing and aeromagnetic data.

Materials and methods
A number of prone areas with different concentrations of gold in Dehaj-Sarduiyeh copper belt including Sar Kuh, Abdar, Meiduk, Sarcheshmeh, Darrehzar, Sara, Iju and Seridune were investigated using the processing of Advanced space borne thermal emission and reflection radiometer (ASTER), and aeromagnetic data. Pre-processing acts such as crosstalk correction and Internal Average Relative Reflection (IARR) calibration were implemented on the ASTER data in order to remove noise and acquire surface reflectance. The alteration minerals were discriminated by implementation of appropriate algorithms such as color composite and partial sub-pixel method, and Mixture tuned matched filtering (MTMF) on a pre-processed and calibrated ASTER data. The results were verified by field surveys and laboratory analyses such as spectroscopic studies, optical microscopy, and XRD. The boundary of each deposit was determined by the results obtained from ASTER data. The aeromagnetic data were also processed using different filters like the reduced to the pole first and second vertical derivatives. Then the aeromagnetic data were clipped according to the boundaries determined with ASTER data and were exported into the GIS environment along with the determined abundances of altered minerals for the investigation of the characteristics of areas with a high concentration of gold.
Results
The results of ASTER image processing revealed that the distribution of phyllic alteration is high in the area. It is shown that most of the poor-Gold porphyry copper deposits are associated with widespread phyllic (Kesler et al., 2002). Therefore, the high exposure of phyllic confirms the low amount of gold in the study area. According to aeromagnetic results, the maximum and minimum differences in magnetic intensity were observed at Abdar- Sarkuh and Iju- Seridun, respectively which have high and low concentrations of gold in these deposits. In addition, the results which were obtained from reduced to pole transform revealed most correspondence with gold differences in the deposits.

Discussion
ASTER datasets were conducted on the eight porphyry copper deposits (PCDs) of Urumieh–Dokhtar magmatic belt including Sar Kuh, Abdar, Meiduk, Sarcheshmeh, Darrehzar, Sara, Iju and Seridune to investigate and detect the high potential areas for gold mineralization. ASTER false color composite image of bands 4, 6, and 8 in red green, and blue determined argillic and sericite altered rocks, as light red to pink, and propylitic altered rocks, as dark to light green. The results obtained from MTMF revealed that sericite is the dominant alteration mineral in the area. The discriminated minerals at most occurrences, including Sarcheshmeh, Meiduk, Sereidun, Darrehzar, Abdar and Iju showed a circular to elliptical pattern with sericite as dominant zone, scattered kaolinite and sparse alunite–pyrophyllite, surrounded by a combination of epidote, chlorite, and calcite. Investigation of aeromagnetic data by applying different filters showed that the magnetic intensity is high in areas with a high concentration of gold. For example, the maximum differences in magnetic intensity were observed at the Sar Kuh and Abdar which contain a higher concentration of gold.

Acknowledgements
The authors would like to acknowledge the
Institute of science and high technology and environmental sciences, Graduate University of Advanced Technology, Kerman, Iran for their financial support during this study under the contract number 7.395.

References
Amer, R., Kusky, T. and Mezayen, A.E., 2012. Remote sensing detection of gold related alteration zones in Um Rus area, Central Eastern Desert of Egypt. Advances in Space Research, 49(1): 121–134.
Hosseinjani Zadeh, M., Tangestani, M.H., Roldan, F.V. and Yusta, I., 2014. Sub-pixel mineral mapping of a porphyry copper belt using EO-1 Hyperion data. Advances in Space Research, 53(3): 440–451.
Kerrich, R., Goldfarb, R., Groves, D. and Garwin, S., 2000. The geodynamics of world-class gold deposits: characteristics, space-time distribution, and origins. In: S.G. Hagemann and P.E. Brown (Editors.), Gold in 2000. Society of Economic Geologists, Incorporation. Littleton, Colorado. pp. 501–552.
Kesler, S.E., Chryssoulis, S.L. and Simon, G., 2002. Gold in porphyry copper deposits: its abundance and fate. Ore Geology Reviews, 21(1–2): 103–124.
Shafiei, B. and Shahabpour, J., 2008. Gold distribution in porphyry copper deposits of Kerman region, Southeastern Iran. Journal of Science, Islamic Republic of Iran, 19(3): 247–260.
Shahriari, H., Honarmand, M. and Ranjbar, H., 2015. Comparison of multi-temporal ASTER images for hydrothermal alteration mapping using a fractal-aided SAM method. International Journal of Remote Sensing, 36(5): 1271–1289.
Sillitoe, R.H., 1979. Some thoughts on gold-rich porphyry copper deposits. Mineralium Deposita, 14(2): 161–174.
Tayebi, M.H. and Tangestani, M.H., 2015. Sub pixel mapping of alteration minerals using SOM neural network model and Hyperion data. Earth Science informatics, 8(2): 279–291.

Keywords

• Aeromagnetic data
• Porphyry copper deposits
• Remote sensing
• gold
• Dehaj-Sarduiyeh belt of Kerman

20.1001.1.20087306.1397.10.1.12.5

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References

Amer, R., Kusky, T. and Mezayen, A.E., 2012. Remote sensing detection of gold related alteration zones in Um Rus area, Central Eastern Desert of Egypt. Advances in Space Research, 49(1): 121–134.

Barzegar, H., 2007. Geology, petrology and geochemical characteristics of alteration zones within the Seridune prospect, Kerman, Iran. Ph.D. Thesis, RWTH Aachen University, Aachen, Germany, 180 pp.

Bedini, E., 2011, Mineral mapping in the Kap Simpson complex, central East Greenland, using HyMap and ASTER remote sensing data. Advances in Space Research, 47(1): 60–73.

Bishop, C.A., Liu, J.G. and Mason, P.J., 2011. Hyperspectral remote sensing for mineral exploration in Pulang, Yunnan Province, China. International Journal of Remote Sensing, 32(9): 2409–2426.

Boadi, B., Wemegah, D.D. and Preko, K., 2013. Geological and structural interpretation of the Konongo area of the Ashanti gold belt of Ghana from aeromagnetic and radiometric data. International Research Journal of Geology and Mining, 3(3): 124–135.

Boardman, J.W., 1998. Leveraging the high dimensionality of AVIRIS data for improved subpixel target unmixing and rejection of false positives: mixture tuned matched filterin. 5th JPL Geoscience Workshop, NASA Jet Propulsion Laboratory, California, United States.

Boardman, J.W., Kruse, F.A. and Green, R.O., 1995. Mapping target signatures via partial unmixing of AVIRIS data. 5th JPL airborne earth science workshop, NASA Jet Propulsion Laboratory, California, United States.

Calvin, W.M., Kratt, C. and Faulds, J.E., 2005. Infrared spectroscopy for drillhole lithology and mineralogy. Thirtieth Workshop on Geothermal Reservoir Engineering, Stanford University, California, United States.

Cox, D.P. and Singer, D.A., 1988. Distribution of gold in porphyry copper deposits. Geological Survey Bulletin, United States, Report 88–46, 26 pp.

Dimitrijevic, M., 1973. Geology of Kerman region. Geological Survey of Iran, Tehran, Iran, Report 52, 334 pp.

Dimitrijevic, M.D., Dimitrijevic, M.N. and Djordjevic, M., 1971a. Geological map of Shahre Babak, 1:100000. Geological Survey of Iran. Tehran, Iran.

Dimitrijevic, M.D, Dimitrijevic, M.N., Djordjevic, M. and Vulovic, D., 1973. Geological map of Pariz, 1:100000. Geological Survey of Iran, Tehran, Iran.

Dimitrijevic, M.D, Djordjevic, M. and Petrovic, Z., 1971b. Geological map of Robat, scale: 1:100000. Geological Survey of Iran, Tehran, Iran.

Dimitrijevic, M.N., Cvetic, S. and Dimitrijevic, M.D., 1972. Geological map of Anar, scale: 1:100000. Geological Survey of Iran, Tehran, Iran.

Djokvoic, I., Cvetic, S. and Dimitrijevic, M.D., 1973. Geological map of Dehaj, scale: 1:100000. Geological Survey of Iran, Tehran, Iran.

ENVI User Guide., 2003. ENVI Software Package Version. 4.5. Reaserach System incorporation, United States, 1084 pp.

Gabr, S., Ghulam, A. and Kusky, T., 2010. Detecting areas of high-potential gold mineralization using ASTER data. Ore Geology Reviews, 38(1–2): 59–69.

Galvao, L.S., Filho R.A. and Vitorello, C., 2005. Spectral discrimination of hydrothermal altered materials using ASTER Short wave infrared bands: Evalation in a tropical Savannah Environment. International Journal of Applied Earth Observation and Geoinformation, 7(2): 107–114.

Ganiyu, S.A., Badmus, B.S., Awoyemi, M.O., Akinyemi, O.D. and Olurin, O.T., 2013. Upward Continuation and Reduction to Pole Process on Aeromagnetic Data of Ibadan Area, South-Western Nigeria. Earth Science Research, 2(1): 66–73.

Guilbert, J.M. and Lowell, J.D., 1974. Variations in zoning patterns in porphyry ore deposits. Canadian Mining and Metallurgical Bulletin (Canadian Institute of Mining and Metallurgy) Montreal, 76(742): 99–109.

Henderson, J.R., Stromquist, J.R.A. and Jespersen, A., 1966. Aeromagnetic map of parts of the Mother Lode gold and Sierra foothills copper mining districts, California, and its geologic interpretation. Department of' the interior United States Geological Survey, Washington. D.C., map GP-561, 4 PP.

Honarmand, M., Ranjbar, H. and Moezifar, Z., 2004. Integration and analysis of Airborne geophysical and remote sensing data of Sar Cheshmeh area, using directed principal component analysis. Exploration and Mining Geology, 11(1–4): 43–48.

Honarmand, M., Ranjbar, H. and Shahabpour, J., 2012. Application of Principal Component Analysis and Spectral Angle Mapper in the Mapping of Hydrothermal Alteration in the Jebal–Barez Area, Southeastern Iran. Resource Geology, 62(2): 119–139.

Hosseinjani Zadeh, M., 2008. Comparison of advanced spectral processing of ASTER data in discrimination of alteration zones and lithological units, a case study from Sarduiyeh geological map 1:100000, Kerman, SE Iran. M.Sc. Thesis, Shiraz University, Shiraz, Iran, 188 pp.

Hosseinjani Zadeh, M., 2013. Evaluating relationship between alteration and mineralization using spectral analysis and processing of multispectral and hyperspectral data, a case study from central part of Dehaj-Sarduiyeh belt, Kerman province, SE Iran. Ph.D. Thesis, Shiraz University, Shiraz, Iran, 236 pp.

Hosseinjani Zadeh, M. and Tangestani, M.H., 2011. Mapping alteration minerals using sub-pixel unmixing of ASTER data in the Sarduiyeh area, SE Kerman, Iran. International Journal of Digital Earth, 4(6): 487–504.

Hosseinjani Zadeh, M., Tangestani, M.H., Roldan, F.V. and Yusta, I., 2014a. Sub-pixel mineral mapping of a porphyry copper belt using EO-1 Hyperion data. Advances in Space Research, 53(3): 440–451.

Hosseinjani Zadeh, M., Tangestani, M.H., Velasco Roldan, F. and Yusta, I., 2014b. Spectral characteristics of minerals in alteration zones associated with porphyry copper deposits in the middle part of Kerman copper belt, SE Iran. Ore Geology Reviews, 62: 191–198.

Hosseinjani Zadeh, M., Tangestani, M.H., Velasco Roldan, F. and Yusta, I., 2014c. Mineral Exploration and Alteration Zone Mapping Using Mixture Tuned Matched Filtering Approach on ASTER Data at the Central Part of Dehaj-Sarduiyeh Copper Belt, SE Iran. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 7(1): 284–289.

Kerrich, R., Goldfarb, R., Groves, D. and Garwin, S., 2000. The geodynamics of world-class gold deposits: characteristics, space-time distribution, and origins. In: S.G. Hagemann and P.E. Brown (Editors.), Gold in 2000. Society of Economic Geologists, Incorporation. Littleton, Colorado. pp. 501–552.

Kesler, S.E., 1973. Copper, molybdenum, and gold abundances in porphyry copper deposits. Economic Geology, 68(1): 106–112.

Kesler, S.E., Chryssoulis, S.L. and Simon, G., 2002. Gold in porphyry copper deposits: its abundance and fate. Ore Geology Reviews, 21(1–2): 103–124.

Kruse, F.A., Boardman, J.W. and Huntigton, J.F., 2003. Comparison of Airborne Hyperspectral Data and EO-1 Hyperion for Mineral Mapping. IEEE Transactions on Geoscience and Remote Sensing, 41(6): 1388–1400.

Lowell, J.D., 1989. Gold mineralization in porphyry copper deposits discussed. Mining Engineering, 41(4): 227–231.

Lowell, J.D. and Guilbert, J.M., 1970. Lateral and vertical alteration-mineralization zoning in porphyry ore deposits. Economic Geology, 65(4): 373–408.

Mars, J. C., 2010. VINR-SWIR and TIR Remote Sensing of Porphyry Copper Deposits. In: D.A. John (Editor), Porphyry Copper Deposit Model. U.S. Geological Survey, Reston, Virginia, pp. 38–50.

Neawsuparp, K., Charusiri, P. and Meyers, J., 2005. New processing of airborne magnetic and electromagnetic data and interpretation for subsurface structures in the Loei area, Northeastern Thailand. Science Asia, 31(3): 283–298.

Nedimovic, R., 1973. Exploration for ore deposits in Kerman region. Geological Survey of Iran, Tehran, Iran, Report, Yu/53, 247 pp.

Qiu, F., Abdelsalam, M. and Thakka, P., 2006. Spectral analysis of ASTER data covering part of the Neoproterozoic Allaqi-Heiani suture, Southern Egypt. Journal of African Earth Sciences, 44(2):169–180.

Ranjbar, H. Hassanzadeh, H., Torabi, M. and Ilaghi, O., 2001. Integration and analysis of airborne geophysical data of the Darrehzar area, Kerman Province, Iran, using principal component analysis. Journal of Applied Geophysics, 48(1): 33–41.

Ranjbar, H., Masoumi, F. and Carranza, E.J.M., 2011. Evaluation of geophysics and spaceborne multispectral data for alteration mapping in the Sar Cheshmeh mining area, Iran. International Journal of Remote Sensing, 32(12): 3309–3327.

Ranjbar, H., Shahriari, H. and Honarmand, M., 2004. Integration of ASTER and Airborne Geophysical Data for Exploration of Copper Mineralization; A case study of Sar Cheshmeh Area. XXth ISPRS Congress, International Society for Photogrammetry and Remote Sensing (ISPRS), Istanbul, Turkey.

Shafiei, B. and Shahabpour, J., 2008. Gold distribution in porphyry copper deposits of Kerman region, Southeastern Iran. Journal of Science, Islamic Republic of Iran, 19(3): 247–260.

Shahriari, H., Honarmand, M. and Ranjbar, H., 2015. Comparison of multi-temporal ASTER images for hydrothermal alteration mapping using a fractal-aided SAM method. International Journal of Remote Sensing, 36(5): 1271–1289.

Shayestefar, M., Mohammadi, M., Rezaei, A. and Ranjbar, H., 2014. Choromit exploration using analysis of 1:50000 aeromagnetic data, Abdasht, Esfandaghe, Kerman. Journal of Engineering Geology and Environment, 24(94): 51–58. (in Persian with English abstract)

Sillitoe, R.H., 1979. Some thoughts on gold-rich porphyry copper deposits. Mineralium Deposita, 14(2): 161–174.

Silva, A.M., Pires, A.C. and McCaffery, A., 2003. Application of airborne geophysical data to mineral exploration in the uneven exposed terrains of the Rio Das Velhas greenstone belt. Revista Brasileira de Geociencias, 33(2): 17-28.

Tayebi, M.H. and Tangestani, M.H., 2015. Sub pixel mapping of alteration minerals using SOM neural network model and Hyperion data. Earth Science informatics, 8(2): 279–291.

Tayebi, M.H., Tangestani, M.H., Vincent, R.K. and Neal, D., 2014. Spectral properties and ASTER-based alteration mapping of Masahim volcano facies, SE Iran. Journal of Volcanology and Geothermal Research, 287: 40–50.

Telford, W.M., Geldart, L.P. and Sheriff, R.E., 1990. Applied Geophysics. Cambridge University Press, New Yory, USA, 770 pp.

Titley, S.R., 1978. Copper, molybdenum, and gold content of some porphyry copper systems of the southwestern and western Pacific. Economic Geology, 73(5): 977–981.

Tommaso, I.D. and Rubinstein, N., 2007. Hydrothermal alteration mapping using ASTER data in the Infiernillo porphyry deposit, Argentina. Ore Geology Reviews, 32(1-2): 275–290.

Waterman, G. and Hamilton, N., 1975. The Sarcheshme Phorphyry Copper Deposit. Economic Geology, 70(3): 568–576.

Zhang, X., Pazner, M. and Duke, N., 2007. Lithologic and mineral information extraction for gold exploration using ASTER data in the south Chocolate Mountains (California). (ISPRS) Journal of Photogrammetry and Remote Sensing, 62(4): 271–282.