polarization (IP) and electrical resistivity (RS) methods have an important role. Due to ... Principles of induced polarization for geophysical exploration (Vol. 5).
Introduction Meyduk (Latala) area is located in Shahr-e Babak (Kerman province). The rock outcrops of Meyduk exploratory (Latala) area is included a small part of the northeastern border of Shahr-e Babak sheet. The most significant feature of the mineralization in the study area is vein-veinlet mineralization zones which are controlled by faults and fault zones. The use of geophysical methods for exploration of metallic and non-metallic ores is quite common. In order to identify and explore disseminated metal and sulfide mineralization zones, induced polarization (IP) and electrical resistivity (RS) methods have an important role. Due to discovery the outcrops in the north of Meyduk (Latala) and preliminary geological surveys, induced polarization and resistivity data acquired by rectangle and dipole-dipole arrays to prospecting and exploration of gold deposits. The rectangle array is covered a wide area at least time and this possibility helps us to do our target with low price. Furthermore, this array can recognize prone areas in order to more detailed investigations. Therefore the dipole-dipole array plays a key role in gaining detailed information and inverse modeling of the data provides the possibility of evaluation of the chargeability and resistivity sections. Method Due to the rock outcrops in the north of Meyduk (Latala) and preliminary geological surveys, 11 rectangle arrays of chargeability and resistivity with current electrode spacing of 600 m, station interval of 20 m and profile interval of 50 m carried out. The relative position and geological map of the study area are shown in figure (1). a
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Figure 1: a) The location of Meyduk in Kerman province and satellite image of the study area that indicates relative position of Latala. b) Geological map of the study area. The survey data were contoured by Geosoft software in order to determine the prone area (Figure (2)). It’s expected that ore areas are containing high chargeability and colored spectral from orange to purple in the contoured IP map, have a low resistivity in the RS map, according to copper mineralization (as malachite and azurite in the fractures) and in some cases propylitic, sericitic and argillic alterations. However, this case is violated in some sections due to low mineralization and presence of very thin veinlet into high electrical resistance rocks. Two main veins are obvious in these contoured maps but we focused on the vein that is located in the right of the maps. We used dipole-dipole array for more accuracy in the next step. The profiles are almost perpendicular to the main vein. In order to determine this vein, 9 parallel profiles with electrode spacing of 20 m and 40 m were carried out. The data-derived profiles were plotted using Res2dinv and Surfer software programs (Figure (3)). The direction of expecting anomaly is simply visible in 2D chargeability and resistivity sections. 79th EAGE Conference & Exhibition 2017 – Student Programme Paris, France, 12-15 June 2017
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Figure 2: a) Chargeability map of the rectangle array, b) Resistivity map of the rectangle array. Black lines and dotes indicate survey profiles of dipole-dipole and stations of rectangle array, respectively. The yellow rectangle is defined the area of considered vein.
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Figure 3: Consecutive sections that were numbered from 1 to 9. a) Chargeability sections, b) Resistivity sections. Conclusion In order to explore sulfidic gold vein, we used IP and RS methods in this area. The maps of chargeability and resistivity of the rectangle array and 2D of the dipole-dipole array were plotted. As we had expected, the vein is located in direction N45E. The results show that depth of anomalies begin from a few meters and continues to more than 100 m that indicates good choice of the electrode spacing and the length of expanding. Reference RES2DINV, M., Ver. 3.5.,[2002]. Rapid 2D resistivity and ip inversion., Geotomo software. Reynolds, J.M., [2011]. An introduction to applied and environmental geophysics. John Wiley & Sons. Sumner, J.S., [2012]. Principles of induced polarization for geophysical exploration (Vol. 5). Elsevier. Tavakoli, S., Bauer, T.E., Rasmussen, T.M., Weihed, P. and Elming, S.Å., [2016]. Deep massive sulphide exploration using 2D and 3D geoelectrical and induced polarization data in Skellefte mining district, northern Sweden.Geophysical Prospecting. Telford, W.M., Geldart, L.P. and Sheriff, R.E., [1990]. Applied geophysics (Vol. 1). Cambridge university press. 79th EAGE Conference & Exhibition 2017 – Student Programme Paris, France, 12-15 June 2017
