Predictive Mapping of Prospectivity in the Gurupi Orogenic Gold Belt, North–Northeast Brazil: An Example of District-Scale Mineral System Approach to Exploration Targeting

Campos, Leandro Duarte; Souza, Sulsiene Machado de; Sordi, Diogo Alves de; Tavares, Felipe Mattos; Klein, Evandro Luíz; Lopes, Elem Cristina dos Santos

doi:10.1007/s11053-016-9320-5

Cited by 18 publications

(11 citation statements)

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“…In this study, to apply knowledge of critical processes of mineralization in an orogenic gold system to prospectivity analysis (e.g., Groves et al, 2000;McCuaig et al, 2010;Lisitsin et al, 2010;Herbert et al, 2014;Asadi et al, 2016;Duarte Campos, 2017), district-scale mapping of prospectivity for the deposit-type sought was considered appropriate to delineate target areas for further exploration at camp-scale. Following the discussion in Carranza et al (2015), district-scale of mapping was selected considering the sorts of data available in the study area (see next sub-section), which is covered by the 1:100,000 scale geological map ( Fig.…”

Section: General Characteristics Of Orogenic Gold Depositsmentioning

confidence: 99%

“…The explanation for that is that deformation causes the less competent metasedimentary country rocks to fail by shearing, but given that these rocks are very tight due to previous shortening and deformation no, or only very little, new space is created. The granitoid bodies, on the other hand, fail by fracturing creating low stress sites and space for gold deposition.The fracturing event triggers increased permeability and suction and thus focuses fluid flow into the newly created facture network / stockwork, centered upon granitoid intrusions.Orogenic-gold deposits are associated with indicative geochemical anomalies, which have been widely used as a reconnaissance-scale exploration tool (Nykänen, 2008; Nykänen et al, 2008a,b;Nykänen and Salmirinne, 2007;Bierlein and McKnight, 2005;Fu et al, 2012;Groves et al, 2000;Goldfarb et al, 2001;.In this study, to apply knowledge of critical processes of mineralization in an orogenic gold system to prospectivity analysis (e.g., Groves et al, 2000;McCuaig et al, 2010;Lisitsin et al, 2010;Herbert et al, 2014;Asadi et al, 2016;Duarte Campos, 2017), district-scale mapping of prospectivity for the deposit-type sought was considered appropriate to delineate target areas for further exploration at camp-scale. Following the discussion in Carranza et al (2015), district-scale of mapping was selected considering the sorts of data available in the study area (see next sub-section), which is covered by the 1:100,000 scale geological map ( Fig.…”

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confidence: 97%

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Prospectivity analysis of orogenic gold deposits in Saqez-Sardasht Goldfield, Zagros Orogen, Iran

Almasi

Yousefi

Carranza

2017

Ore Geology Reviews

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Diverse deposit-types or mineral systems form by diverse geological processes, so translation of knowledge about the controls of mineralization acquired from the 4D geological modeling into 2D spatial predictor maps is a major challenge for prospectivity analysis. In this regard, mathematical functions have been used to model the conceptual or perceived spatial relationships between geological variables and targeted type or system of mineralization. In this paper, due to the different models of spatial relationships between predictors and mineral deposits, we investigated the performance of different fuzzification functions to quantify the relationships. We demonstrated that various types of relationships between exploration features and a mineralization-type sought could be quantified using different fuzzification functions for prospectivity analysis. We illustrated the process of the prospectivity analysis by using a data set of orogenic gold deposits in Saqez-Sardasht Goldfield, Iran. Prospectivity modeling of orogenic gold mineralization in the study area showed that the NE-SW trending targets have priority for further prospecting of the deposits. Saqez-Sardasht Goldfield, Zagros Orogen, Iran (by A. Almasi, M. Yousefi, E. J.M. Carranza) Manuscript submitted to Ore Geology Reviews 2 Prospectivity analysis of orogenic gold deposits in IntroductionFor mineral prospectivity mapping (MPM) of a deposit-type sought in an area, mathematical functions have been used to model spatial relationships between geological variables system of mineralization (e.g., Bonham-Carter, 1994;Luo and Dimitrakopoulos, 2003; Porwal et al., 2003a,b,c;Carranza, 2008Carranza, , 2017. In MPM, mathematical functions, have been widely used to assign weights to discretized spatial evidence values as fuzzified evidential maps in the [0,1] range or to rank target areas as fuzzy prospectivity models (e.g., Bonham-Carter, 1994;Carranza and Hale, 2002;Luo and Dimitrakopoulos, 2003;Porwal et al., 2003c;Carranza, 2008Carranza, , 2009Carranza, , 2017Lisitsin et al., 2013;Mutele et al., 2017;Nykänen et al., 2017). The weights assigned to classes of discretized evidential values may be based on (a) expert judgment directly, (b) locations of known mineral occurrences (KMOs), (c) a combination of (a) and (b), or (d) subjectively-defined functions, so indirectly-assigned by analyst (e.g., Luo, 1990;Bonham-Carter, 1994;Cheng and Agterberg, 1999;Luo and Dimitrakopoulos, 2003;Porwal et al., 2003a Porwal et al., ,b,c, 2004Porwal et al., , 2006Carranza et al., 2005;Carranza, 2008Carranza, , 2014Porwal and Kreuzer, 2010;Mejía-Herrera et al., 2014;Carranza and Laborte, 2016;McKay and Harris, 2016). All these methods impart bias due to discretization of continuous spatial values, use of subjective expert judgments, and sparse or incomplete data on locations of KMOs in knowledge-and data-driven MPM (Coolbaugh et al., 2007;Lusty et al., 2012;Ford et al., 2016).To reduce bias in the assignment of weights to continuous-value spatial evidence, various re...

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Section: General Characteristics Of Orogenic Gold Depositsmentioning

confidence: 99%

mentioning

confidence: 97%

Prospectivity analysis of orogenic gold deposits in Saqez-Sardasht Goldfield, Zagros Orogen, Iran

Almasi

Yousefi

Carranza

2017

Ore Geology Reviews

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“…By comparing the results of our study with the existing geological map (Figures 5 and 6), most of the ore mineralization was observed to occur within the most areas of high hydrothermal intensity. This is because the hydrothermal ore body probably located in areas of high intensity of hydrothermal alteration [8,42]. The presence of mineralized zones along the contact of the granite pluton and country rocks and sheeted quartz veins cutting the granite itself and country rocks revealed the existence of multiphase of mineralizations that need further field investigations in the future.…”

Section: Discussionmentioning

confidence: 99%

“…Geographic Information System (GIS) tools have been used to produce integrative maps through digital overlay methods [8,38,39]. Knowledge-driven approaches integrating multicriteria decision-making depending on expert judgement have also been used to produce predictive maps [40][41][42]. Such approaches employs ranked binary evidential maps.…”

Section: Introductionmentioning

confidence: 99%

Application of remote sensing and GIS techniques for exploring potential areas of hydrothermal mineralization in the central Eastern Desert of Egypt

Shi

Al‐Arifi

Abdelkareem

et al. 2020

Journal of Taibah University for Science

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The integration of remotely sensed data allowed the successful characterization of the hydrothermal alteration zones of the Abu-Gaharish area in the Central Eastern Desert of Egypt using image transformation techniques. The integration of several evidential maps highlighted the plausible areas with high concentrations of argillic and phyllic, key hydrothermal minerals that reflect the intensity of hydrothermal effects and the probable sites of ore bodies. The excellent prospective zone identified in the map occupies around 1.39% of the study area. Kaolinite-smectite minerals with correlation scores of around 0.97 were consistent with areas of hydrothermal alteration and mining activities; however, propylitic minerals were confined to basic metavolcanics and serpentinites. The resulting predictive map was assessed using existing mining data with significant consistency; therefore, field verification is essential. The overall results showed that remotely sensed data represent a valuable mapping tool for geological and mineral resources reconnaissance in the arid regions ARTICLE HISTORY

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“…Since the advent of GIS-based spatial analysis approaches, advances have been achieved in revealing prospective areas of hydrothermal mineral resources [24][25][26]. This is because integration of spatially distributed remote-sensing data using a GIS technique is a significant approach to mineral exploration, as it allows combining multiple datasets through digital overlay methods in order to optimize mineral prospection maps [27]. For example, the GISbased knowledge-driven method is efficient to produce predictive maps based on expert judgment [8] as each GIS predictive layer is assigned a weight reflecting importance in the modeling process [1,24].…”

Section: Introductionmentioning

confidence: 99%

Synergy of Remote Sensing Data for Exploring Hydrothermal Mineral Resources Using GIS-Based Fuzzy Logic Approach

Abdelkareem

Al‐Arifi

2021

Remote Sensing

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The Arabian Nubian Shield (ANS) contains a variety of gold deposits in the form of veins and veinlets formed by hydrothermal fluids. Characterizing potential areas of hydrothermal alteration zones therefore provides a significant tool for prospecting for hydrothermal gold deposits. In this study, we develop a model of exploration for hydrothermal mineral resources in an area located in the ANS, Egypt, using multiple criteria derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Landsat-Operational Land Imager (OLI), and Sentinel-2 data and field work through GIS-based fuzzy logic approach. The hydrothermal alteration zones (HAZs) map extracted from combining mineral indices, spectral bands, and ratios is consistent with observed argillic alteration zones around the mineralized veins. Combining HAZs and lineament density led to identification of six zones based on their mineralization potential, and provides a tool for successful reconnaissance prospecting for future hydrothermal mineral deposits. The detected zones are labeled as excellent, very high, high, moderate, low, and very low, based on their potential for Au production, and the predictive excellent and very high zones cover about 1.6% of the study area. This model also shows that target prospective zones are quartz veins controlled by NNW-SSE trending fracture/fault zones all crosscutting Precambrian rocks of the ANS. Field observations and petrographic and X-ray diffraction analyses were performed to validate the mineral prospective map and revealed that quartz veins consist of gold–sulfide mineralization (e.g., gold, pyrite, chalcopyrite, and sphalerite). Consistency between the high potential hydrothermal alterations zones (HAZs) and the location of gold mineralization is achieved.

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Predictive Mapping of Prospectivity in the Gurupi Orogenic Gold Belt, North–Northeast Brazil: An Example of District-Scale Mineral System Approach to Exploration Targeting

Cited by 18 publications

References 29 publications

Prospectivity analysis of orogenic gold deposits in Saqez-Sardasht Goldfield, Zagros Orogen, Iran

Prospectivity analysis of orogenic gold deposits in Saqez-Sardasht Goldfield, Zagros Orogen, Iran

Application of remote sensing and GIS techniques for exploring potential areas of hydrothermal mineralization in the central Eastern Desert of Egypt

Synergy of Remote Sensing Data for Exploring Hydrothermal Mineral Resources Using GIS-Based Fuzzy Logic Approach

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