A method for extracting anomaly map of Au and As using combination of U-statistic and Euclidean distance methods in Susanvar district, Iran

Abstract

Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemical anomalies. The U-statistic method is one of the most important structural methods and is a kind of weighted mean that surrounding points of samples are considered in U value determination. However, it is able to separate the different anomalies based on only one variable. The main aim of the presented study is development of this method in a multivariate mode. For this purpose, U-statistic method should be combined with a multivariate method which devotes a new value to each sample based on several variables. Therefore, at the first step, the optimum p is calculated in p-norm distance and then U-statistic method is applied on p-norm distance values of the samples because p-norm distance is calculated based on several variables. This method is a combination of efficient U-statistic method and p-norm distance and is used for the first time in this research. Results show that p-norm distance of p=2 (Euclidean distance) in the case of a fact that Au and As can be considered optimized p-norm distance with the lowest error. The samples indicated by the combination of these methods as anomalous are more regular, less dispersed and more accurate than using just the U-statistic or other nonstructural methods such as Mahalanobis distance. Also it was observed that the combination results are closely associated with the defined Au ore indication within the studied area. Finally, univariate and bivariate geochemical anomaly maps are provided for Au and As, which have been respectively prepared using U-statistic and its combination with Euclidean distance method.

Keywords

mineral anomaly / Susanvar district / U-statistic method / Euclidean distance / bivariate anomaly map

References

[1] ShamanianG H, HedenquistJ W, HattoriK H, HassanzadehJ. The Gandy and Abolhassani epithermal deposits in the Alborz magmatic arc, Semnan Province, northern Iran [J]. Economic Geology, 2004, 99: 691-712

[2] KazminV G, SborshikovI M, RicouL E, ZorenshainE P, BoulinS, KnipperA L. Volcanic belts as markers of the Mesozoic-Cenozoic active margin of Eurasia [J]. Tectonophysics, 1986, 123: 123-152

[3] AlaviMTectonic map of the Middle East, 1:5000000 [M], 1991, Tehran, Iran, Geologic Survey of Iran

[4] HassanzadehJ, GhaziA V, AxenG, GuestB. Oligomiocene mafic-alkaline magmatism in north and northwest of Iran: Evidence for the separation of the Alborz from the Urumieh-Dokhtar magmatic arc [J]. Geological Society America Abstracts with Program, 2002, 34: 331

[5] ShamanianG H, HedenquistJ W, HattoriK H, HassanzadehJEpithermal precious-and base-metal mineralization in the Eocene arc of Torud-Chah Shirin mountain range: Gandy and Abolhassani districts, Semnan, northern Iran [C]//ELIOPOULOS D G, et al, 2003, Mineral Exploration and Sustainable Development. Rotterdam, Mill Press: 519-522

[6] Geological Survey of Iran.Explanatory text of geochemical map of Moaleman (6960) [R], 1995, 1: 33

[7] GhannadpourS S, HezarkhaniA. Lead and zinc geochemical behavior based on geological characteristics in Parkam Porphyry Copper System, Kerman, Iran [J]. Journal of Central of South University, 2015, 224274-4290

[8] GhannadpourS S, HezarkhaniA. Investigation of Cu, Mo, Pb, and Zn geochemical behavior and geological interpretations for Parkam porphyry copper system, Kerman, Iran [J]. Arabian Journal of Geosciences, 2015, 8(9): 7273-7284

[9] GhannadpourS S, HezarkhaniA. Developed software to calculate the additive constant number of average in three–variable normal logarithm [J]. Global Journal of Computer Sciences, 2012, 2: 7-13

[10] HawkesH E, WebbJ S. Geochemistry in mineral exploration [M]. New York: Harper and Row, 1962415

[11] MieschA T. Estimation of the geochemical threshold and its statistical significance [J]. Journal of Geochemical Exploration, 1981, 16: 49-76

[12] SinclairA J. A fundamental approach to threshold estimation in exploration geochemistry: Probability plots revisited [J]. Journal of Geochemical Exploration, 1991, 41: 1-22

[13] ChengQ, AgterbergF P, BallantyneS B. The separation of geochemical anomalies from background by fractal methods [J]. Journal of Geochemical Exploration, 1994, 51: 109-130

[14] ChengQ, AgterbergF P, Bonham-CarterG F. A spatial analysis method for geochemical anomaly separation [J]. Journal of Geochemical Exploration, 1996, 56: 183-195

[15] ChengQ. Spatial and scaling modelling for geochemical anomaly separation [J]. Journal of Geochemical Exploration, 1999, 65: 175-194

[16] GoncalvesM A, MateusA, OliveriaV. Geochemical anomaly separation by multifractal modeling [J]. Journal of Geochemical Exploration, 2001, 72: 91-114

[17] LiC, MaT, ShiJ. Application of a fractal method relating concentrations and distances for separation of geochemical anomalies from background [J]. Journal of Geochemical Exploration, 2003, 77: 167-175

[18] ZuoR. Identifying geochemical anomalies associated with Cu and Pb–Zn skarn mineralization using principal component analysis and spectrum–area fractal modeling in the Gangdese Belt, Tibet (China) [J]. Journal of Geochemical Exploration, 2011, 111: 13-22

[19] RoshaniP, MokhtariA R, TabatabaeiS H. Objective based geochemical anomaly detection—Application of discriminant function analysis in anomaly delineation in the Kuh Panj porphyry Cu mineralization (Iran) [J]. Journal of Geochemical Exploration, 2013, 130: 65-73

[20] GhannadpourS S, HezarkhaniA. Introducing 3D U-statistic method for separating anomaly from background in exploration geochemical data with associated software development [J]. Journal of Earth System Science, 2016, 125(2): 387-401

[21] GhannadpourS S, HezarkhaniA. Exploration geochemistry data-application for anomaly separation based on discriminant function analysis in the Parkam porphyry system (Iran) [J]. Geosciences Journal, 2016, 20(6): 837-850

[22] GhannadpourS S, HezarkhaniA, MaghsoudiA, FarahbakhshE. Assessment of prospective areas for providing the geochemical anomaly maps of lead and zinc in Parkam district, Kerman, Iran [J]. Geosciences Journal, 2015, 8(1): 345-355

[23] GhannadpourS S, HezarkhaniA, SabetmobarhanA. The Parkam exploration district, Kerman, Iran: Geology, alterations, and delineation of Cu- and Mo-mineralized zones using U-spatial statistic with associated software development [J]. Journal of Earth Science, 2017, 28(2): 283-294

[24] GhannadpourS S, HezarkhaniA. Comparing U-statistic and nonstructural methods for separating anomaly and generating geochemical anomaly maps of Cu and Mo in Parkam district, Kerman, Iran [J]. Carbonates and Evaporites, 2017, 32(2): 155-166

[25] GhannadpourS S, HezarkhaniAProviding the bivariate anomaly map of Cu–Mo and Pb–Zn using combination of statistic methods in Parkam district, Iran [J], 2017

[26] FilzmoserP, GarrettR G, ReimannC. Multivariate outlier detection in exploration geochemistry [J]. Computer & Geosciences, 2005, 31: 579-587

[27] RamzanS, ZahidF M, RamzanS. Evaluating multivariate normality: A graphical approach [J]. Middle-East Journal of Scientific Research, 2013, 13: 254-263

[28] MerinoD IThe distance between a point and a line using different norms [D], 2002, Cadence Lee Ellington, Southeastern Louisiana University: 12

[29] GhannadpourS S, HezarkhaniA, RoodpeymaT. Combination of separation methods and data mining techniques for prediction of anomalous areas in Susanvar, Central Iran [J]. Journal of African Earth Sciences, 2017, 134: 516-525

[30] GhannadpourS S, HezarkhaniAApplying the combination of U-statistic and Mahalanobis distance as a multivariate structural method for the delineation of geochemical anomalies [J], 2017

[31] HEZARKHANI A, GHANNADPOUR S S. Exploration information analysis [M]. First ed. Tehran, Iran: Amirkabir University of Technology (Tehran Polytechnic) Press, 2015: 245. (in Persian)

[32] GhannadpourS SGeochemical studies of porphyry copper ore deposit of Parkam, Tehran [D], 2013, Tehran, Iran, Amirkabir University of Technology