South Sudan, a new country formed in 2011, has been planning to develop its mineral sector by allocating exploration licenses to investors. This decision requires preliminary knowledge of geology and mineral occurrences, both of which are unavailable because the country has been engaged in a civil war for more than 50 years. Exploration of mineral resources in South Sudan has lagged behind its petroleum industry, except for artisanal gold mining, which is practiced intermittently by local communities. Freely available satellite gravity and remote-sensing data were used to map the basement architecture as well as zones of hydrothermal alteration in the Didinga Hills; both basement architecture and hydrothermal alteration are of prime importance in exploration and development of mineral resources in the study area. Qualitative interpretation of gravity data is consistent with the known geology of petroleum fields and the Precambrian basement complex. Remote-sensing data and techniques—optimal band combination, band ratioing, and principal component analysis—have been effective in extracting information related to lithology, hydrothermal alteration, and geologic structures. The resulting basic information and methods have identified additional prospective exploration areas where more detailed gravity, magnetic, electromagnetic, and seismic surveys should be carried out; this will assist decision makers in matters related to land use, mineral titles, and exploration of natural resources, and lead to prosperity for the new nation of South Sudan.

Inhomogeneities in the earth (fractures, layering, shape, composition) are responsible for seismic wave scattering and contribute towards amplitude, travel time, frequency and spectral fluctuations observed in seismic records. This thesis presents findings that complement our understanding of seismic scattering and imaging in heterogeneous media. Interest focused on probing the correlation between spatial variations in attributes that characterize the state (physical, chemical) of rocks and seismic waveform data with consideration towards potential implications for seismic survey design to optimize imaging, imaging with converted waves, microseismic monitoring, velocity modeling and imaging of lithological boundaries. The highlights of the research strategy include: • The use of stochastic methods to build realistic earth models that characterize the 1D, 2D and 3D spatial variations in rock properties. These petrophysical earth models are conditioned by experimental (“hard”) data such as geology, wave velocities and density from case study areas like the Bosumtwi impact crater and the base metal deposits in Nash Creek (Canada) and Thompson (Canada). The distributions of the sulfide mineralization at Nash Creek and at Thompson represent two end members of the heterogeneity spectrum. While the sulfide mineralization at Nash Creek is highly disseminated in nature, the sulfide rich zones at Thompson occur as well defined volumes (lens-shaped) having a strong density contrast with respect to the host rocks. • Analysis of modeled forward (transmitted) and backward scattered wave propagation in the heterogeneous earth models. As a result of a study aimed at correlating resonant frequencies to scale length parameters, it is observed that the efficiency of the spectral ratio method is undermined by its sensitivity to the interference between P- and S-waves as well as the impedance contrast. It is also demonstrated that travel time of direct arrivals (transmitted waves) can be used to infer structural heterogeneity and velocity distribution beyond borehole locations. However, the success of imaging with transmitted waves is subject to the influence of geology which must factor in the choice of acquisition geometry. For the first time, multivariate and multidimensional (3D) heterogeneous earth models that are conditioned by hard data from multiple boreholes are constructed. The methodology requires having at least one physical rock property attribute that is sampled along the whole borehole length. This approach helped to characterize the uncertainty in the distribution of rock densities and metal content in a study region of the Nash Creek property. The density data suggests the sulfides are disseminated and this poses challenges for both gravity and seismic imaging methods. Modeling studies suggest seismic methods will not be suited for imaging zones with such disseminated mineralization. On the other hand, when dealing with massive sulfide mineralization that has complex geology (steep dip) like the case in Thompson, the success of the seismic imaging process relies very much on the acquisition geometry as well as the variability of the physical properties of the host rock. Elastic modeling results show that a Vertical Seismic Profiling (VSP) geometry is better suited to capture the down-dip scattered wavefield from the orebody. While surface acquisition geometry with sufficient extended length in the down dip direction can also be used to detect the dipping orebody, its efficiency can however be undermined by background heterogeneity: when the scale length along the direction of dip is comparable to the dimensions of the orebody, the scattered wavefields are strong enough to mask the diffraction hyperbola generated from the ore. Moreover, the study also corroborates that converted waves generated from the scattering processes hold promise as an imaging tool for a dipping orebody as they are least affected by the scattering processes of background heterogeneity.

Inhomogeneities in the earth (fractures, layering, shape, composition) are responsible for seismic wave scattering and contribute towards amplitude, travel time, frequency and spectral fluctuations observed in seismic records. This thesis presents findings that complement our understanding of seismic scattering and imaging in heterogeneous media. Interest focused on probing the correlation between spatial variations in attributes that characterize the state (physical, chemical) of rocks and seismic waveform data with consideration towards potential implications for seismic survey design to optimize imaging, imaging with converted waves, microseismic monitoring, velocity modeling and imaging of lithological boundaries. The highlights of the research strategy include: • The use of stochastic methods to build realistic earth models that characterize the 1D, 2D and 3D spatial variations in rock properties. These petrophysical earth models are conditioned by experimental (“hard”) data such as geology, wave velocities and density from case study areas like the Bosumtwi impact crater and the base metal deposits in Nash Creek (Canada) and Thompson (Canada). The distributions of the sulfide mineralization at Nash Creek and at Thompson represent two end members of the heterogeneity spectrum. While the sulfide mineralization at Nash Creek is highly disseminated in nature, the sulfide rich zones at Thompson occur as well defined volumes (lens-shaped) having a strong density contrast with respect to the host rocks. • Analysis of modeled forward (transmitted) and backward scattered wave propagation in the heterogeneous earth models. As a result of a study aimed at correlating resonant frequencies to scale length parameters, it is observed that the efficiency of the spectral ratio method is undermined by its sensitivity to the interference between P- and S-waves as well as the impedance contrast. It is also demonstrated that travel time of direct arrivals (transmitted waves) can be used to infer structural heterogeneity and velocity distribution beyond borehole locations. However, the success of imaging with transmitted waves is subject to the influence of geology which must factor in the choice of acquisition geometry. For the first time, multivariate and multidimensional (3D) heterogeneous earth models that are conditioned by hard data from multiple boreholes are constructed. The methodology requires having at least one physical rock property attribute that is sampled along the whole borehole length. This approach helped to characterize the uncertainty in the distribution of rock densities and metal content in a study region of the Nash Creek property. The density data suggests the sulfides are disseminated and this poses challenges for both gravity and seismic imaging methods. Modeling studies suggest seismic methods will not be suited for imaging zones with such disseminated mineralization. On the other hand, when dealing with massive sulfide mineralization that has complex geology (steep dip) like the case in Thompson, the success of the seismic imaging process relies very much on the acquisition geometry as well as the variability of the physical properties of the host rock. Elastic modeling results show that a Vertical Seismic Profiling (VSP) geometry is better suited to capture the down-dip scattered wavefield from the orebody. While surface acquisition geometry with sufficient extended length in the down dip direction can also be used to detect the dipping orebody, its efficiency can however be undermined by background heterogeneity: when the scale length along the direction of dip is comparable to the dimensions of the orebody, the scattered wavefields are strong enough to mask the diffraction hyperbola generated from the ore. Moreover, the study also corroborates that converted waves generated from the scattering processes hold promise as an imaging tool for a dipping orebody as they are least affected by the scattering processes of background heterogeneity.

Exploration for large zinc silicate deposits is more challenging than zinc sulfide deposits, as they do not exhibit similar geophysical anomalies. The Vazante deposit, which is the world’s largest zinc silicate deposit, occurs in brecciated dolomite and comprises mainly willemite with various proportions of hematite, and minor franklinite and sphalerite. In the Vazante region, the exploration challenge is enhanced as outcrops are rare, bedrock generally sits below 10s of metres of laterite cover and barren hematite-rich breccias have a similar geophysical signature to willemite ore bodies. In order to evaluate the applications of geophysical surveys in the exploration of this type of deposit, data from 475 samples were investigated from drill holes representative of the various types of ore, host rocks and zones of known geophysical anomalies in the Vazante District. Geochemical (ICP-MS and XRF) and mineralogical (optical, EMPA, SEM and MLA) data were integrated with physical rock properties (density, magnetic susceptibility and K-U-Th gamma ray spectrometry) to assist in finding new ore zones. The most distinct physical property of the ore is density (3.0-4.3 g/cm3), compared with the host rocks (2.7-3.0 g/cm3). This is due to high proportion of denser minerals (hematite and willemite) in the ore. However, barren hematite breccias also have high densities (3.0-4.5 g/cm3). The zinc ore and hematite breccias yielded higher magnetic susceptibilities (0.1-38 x10-3 SI) than the surrounding host rocks, with the highest values associated with greater proportions of franklinite and magnetite (7-38 x10-3 SI). The zinc ore has an elevated U concentration (up to 33ppm) relative to the various host rocks (up to 7 ppm), yielding higher gamma spectrometric values. The results of this investigation indicate that an integration of magnetic, gravimetric and radiometric surveys would be required to identify zinc silicate ore zones and potentially differentiate them from barren hematite breccias and host rocks. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-03-27 13:32:54.132

The Skellefte ore district in northern Sweden is a Palaeoproterozoic volcanic arc and one of the most important ones hosting volcanogenic massive sulfide (VMS) deposits, producing mainly base metals and orogenic gold deposits. Due to high metal prices and increased difficulties in finding shallow deposits, the exploration for and exploitation of mineral resources is quickly being moved to greater depths. For this reason, a better understanding of the geological structures in 3D down to a few kilometers depth is required as a tool for ore targeting. As exploration and mining go deeper, it becomes more and more evident why a good understanding of geology in 3D at exploration depths, and even greater, is important to optimize both exploration and mining. Following a successful pilot 3D geological modeling project in the western part of the district, the Kristineberg mining area, a new project "VINNOVA 4D modeling of the Skellefte district" was launched in 2008, with the aim of improving the existing models, especially at shallow depth and extending the models to the central district. More than 100 km of reflection seismic (crooked) profiles were acquired, processed and interpreted in conjunction with geological observations and potential field data. Results were used to constrain the 3D geological model of the study area and provided new insights about the geology and mineral potential at depth. Results along the seismic profiles in the Kristineberg mining area proved the capability of the method for imaging reflections associated with mineralization zones in the area, and we could suggest that the Kristineberg mineralization and associated structures dip to the south down to at least a depth of about 2 km. In the central Skellefte area, we were able to correlate main reflections and diffractions with the major faults and shear zones. Cross-dip analysis, reflection modeling, pre-stack time migration, swath 3D processing and finite-difference seismic modeling allowed insights about the origin of some of the observed reflections and in defining the imaging challenges in the associated geological environments. / VINNOVA 4D modeling of the Skellefte district

The Skellefte District (SD) is one of the richest metallogenic mining areas in Sweden. The main deposits consist of volcanic-hosted massive sulphides (VHMS) rich in zinc, copper, lead, gold and silver, that have been explored and mined for more than a century. Considering that technological advancements allow deeper mining, and that today new discoveries rarely occur, renewed efforts are now directed at locating targets at greater depths.   Thus, current exploration strategies need to be adapted, and a better understanding of regional scale structures is necessary. To address these questions the project VINNOVA 4D modeling of the Skellefte District was launched. Its main purpose is to unravel the regional structures and tectonic setting of the SD. To accomplish this, new geological and geophysical data have been acquired in two key localities. This thesis presents the contribution from 2D and 3D inversion of magnetotelluric (MT) data and seismic reflection data. The main findings include: conductive hydrothermally altered zones within the otherwise resistive rocks of the Skellefte Group, the depth extension of early and postorogenic intrusions, prominent shear zones in the central part of the district, and enhanced reflectivity and conductivity at the base of the Skellefte Group throughout the SD. Even though the application of these methods is challenged by the complex geological setting of the SD, it is shown that after a careful processing and analysis of the data, they are able to provide a robust image of the deep subsurface. Additionally, the combination of reflection seismics and MT has proved to be a powerful tool for hypothesis testing and to develop the general understanding of the configuration and history of the SD. Furthermore, two 3D inversion models of MT data are presented and compared with the results of standard 2D determinant inversions. The 3D procedure shows significant improvements in data fit and is able to constrain better the observed model features. Although 3D inversion of MT data is not yet a run of the mill scheme and issues like model assessment and galvanic distortion effects need to be further addressed, results from complex environments with areal coverage, are already superior to those from 2D inversions. / Skellefteåfälten är ett av de viktigaste malmdistrikten i Sverige. Malmkropparna består av vulkaniskvärda Massiva Sulfider (VHMS) rika på Zink, Koppar, Bly, Guld och Silver, och har utforskats och brutits i mer än ett sekel. Med tanke på att de senaste tekniska framstegen tillåter djupare brytning, och att nya upptäckter är ovanliga idag, riktas nya ansträngningar mot att lokalisera malm på större djup. Aktuella prospekteringsstrategier måste därför anpassas, och en bättre förståelse av regionala strukturer är nödvändig. För att lösa dessa frågor lanserades projektet VINNOVA 4D modeling of the Skellefte District. Dess främsta syfte är att utreda de regionala strukturerna och det tektoniska läget av Skelleftefältet. För att uppnå detta, har nya geologiska och geofysiska data insamlats vid två viktiga platser i distriktet. Denna avhandling presenterar bidrag från inversionsmodellering i 2D och 3D av magnetotelluriska (MT) data samt resultaten av en reflektionsseismisk profil. De viktigaste resultaten är: bra ledande hydrotermiskt förändrade zoner inom de annars resistiva bergarterna i Skellefte-gruppen, djupet till tidiga och postorogeniska intrusioner, framstående skjuvzoner i den centrala delen av området, och ökad reflektionsförmåga och konduktivitet vid basen av Skellefte-gruppen i hela fältet. Även om tillämpningen av dessa metoder utmanas av fältens komplexa geologiska läge, visas det efter en noggrann bearbetning och analys av data att de ger en robust bild av den lite djupare berggrunden. Dessutom har kombinationen av reflektionsseismik och MT visat sig vara ett kraftfullt verktyg för hypotesprövning och för att utveckla den allmänna förståelsen av Skelleftefältet och dess historia. Därutöver presenteras två 3D inversionsmodeller av MT data och jämförs sedan med resultaten från 2D determinantinversioner. 3D tekniker visar betydande förbättringar av datapassform och begränsar observerade anomalier bättre. Även om 3D inversion av MT data ännu inte är en vanlig teknik och frågor som modellbedömning och galvaniska distorsionseffekter måste behandlas ytterligare, är resultat från komplexa miljöer med lagom yttäckning redan överlägsna. / VINNOVA 4D modeling of the Skellefte District

This study provides one of the first accounts of the relationships between termites, termitaria and the pedolith, towards developing their application as a biogeochemical sampling medium for mineral exploration. Mapping regolith–landforms, termitaria, and the associated termitaria biogeochemistry show that termites are an integral control on the organisation of trace metals in the landscapes of northern Australia. In particular, termites are important for transporting geochemical signatures from depth, through the pedolith and to the ground surface. This occurs by way of bioturbative and constructional activities of the mound-building termites, which in this study included Nasutitermes triodiae, Amitermes vitiosus, Drepanotermes rubriceps, Tumulitermes hastilis and T. pastinator. Termitaria from these species are mappable regolith– landform attributes at the local scale; this highlights their specific preferences for colony sites, such as access to vegetation, drainage, and the availability of construction materials. The mound-building termites featured in this study are also soil modifiers, altering the pedolith terms of both structure and chemistry. Developing an understanding of these processes has helped to refine a model for pedolith development through biotic processes, which is applicable to subtropical and tropical climatic regions, where termites act as important ecosystem engineers. This research project fills a niche for new scientific investigation of deeper regolith profiles and associated terrains; it moves away from theories of shallow soil development overlying an abiotic deep regolith, towards understanding pedolith development as wholly biotically driven. For mineral explorers this means that ore-related elements, such as Au, As and Zn, are re-organised and moved towards the land surface in settings such as buried Au-deposits and mineralisation in the Tanami region, and Pine Creek Orogen. A key finding within the study of the application of this technique is that the fine, silt-clay (>79 μm) from termitaria is capable of accurately delineating the surficial expression of buried Au mineralisation. Termitaria can therefore provide an accessible surficial biogeochemical sampling media that can be used in mineral exploration programs / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1369217 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2009

Vegetation sampling is an effective exploration technique in areas of transported cover where other techniques have been of limited success. Several plant species were sampled along transects across 9 known Au ore bodies; Triodia pungens was found give a Au, As, ±Zn, ±S, ±Ce and ±La signature which represented mineralisation through cover materials and Eucalyptus brevifolia was found to give a geobotanical and ±Ca, ±Mg, P, S and Zn signature of underlying geological structure. The Hyperion prospect was used as a ‘blind’ target as there was no background information available until after interpretation was carried out. Mineralisation was located at the contact between granite and dolerite, biogeochemical signatures from E. brevifolia and Acacia bivenosa showed areas of change in ±Au, Ba, Ce, ±Cu, La, ±Mn, Nd, P, S, Sm, Y and Zn which corresponded to this contact. All species in the Pine Creek Orogen were able to present areas elevated in Au, As, ±Zn, ±S, ±Mo and ±Cu which provide future drilling targets. Biogeochemical sampling was able to determine the location of mineralisation at each site and identify underlying substrate changes, however, background knowledge relating to regolith, geology, hydrology and geophysics are important in aiding the interpretation of the elemental data as each component of the substrate influences the elements which a plant will uptake. Mineral exploration in Australia has been driven by the search for large ore deposits close to the surface. This has led to the need to develop technologies for detecting mineral deposits under cover, which can be up to several hundred metres of transported sediments. The aim of this research was to test the feasibility of using vegetation biogeochemical sampling over known Au deposits within semi-arid and arid terrains. Biogeochemical sampling has the advantages of being cost effective, sustainable, environmentally friendly and relatively easy to perform. Nine field sites were covered, 4 in the Tanami Region (Coyote, Larranganni, Hyperion and Titania), 4 in the Pine Creek Orogen (Johns Hill, Great Northern, Glencoe and McKinlay) and 1 in the Gawler Craton (Tunkillia). At each of these sites the dominant species were sampled and the elemental concentrations of the plant were analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to test if they were able to detect buried mineralisation. In general, all species identified as being deep rooted (larger trees, paperbarks and spinifex) were able to detect mineralisation in each location within multi-element dispersion haloes centring over the projected ore body. Variations were dependant upon species differences and root structures, groundwater influences, and the potential for detrital contamination. In arid Australia, Triodia spp. were shown to be ideal for closely spaced tenement/prospect scale exploration, and Heteropogon spp. show similar trends for the humid tropics. Eucalyptus/Corymbia spp. are more suitable for widely spaced regional sampling exploration as they amalgamate a wider signal with strong groundwater influences. It was found that all plant species were effective at expressing buried mineralisation in a multi-element suite (pathfinders: Au, As, S, Zn, +(Ce/La), _Mo and _Cu) through cover in these terrains provided care was taken with sampling and interpretation. Regolith materials, botanical properties and landforms are essential background knowledge for determining the effectiveness of biogeochemical sampling. Plants with deep root systems with little lateral spread are ideal for prospect/tenement mineral exploration programs, and plants with wide lateral spreads and large chemical uptake potentials are ideal for regional mineral exploration programs. This exploration strategy would be quick, sustainable and relatively cheap compared to other methods of exploration. This is not to say that biogeochemical sampling would be the only tool needed for further mineral exploration in Australia. This process would work best if used in conjunction with other sampling methods like geophysics and some soil sampling techniques. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1351318 / Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, School of Earth and Environmental Sciences, 2009

This study provides one of the first accounts of the relationships between termites, termitaria and the pedolith, towards developing their application as a biogeochemical sampling medium for mineral exploration. Mapping regolith–landforms, termitaria, and the associated termitaria biogeochemistry show that termites are an integral control on the organisation of trace metals in the landscapes of northern Australia. In particular, termites are important for transporting geochemical signatures from depth, through the pedolith and to the ground surface. This occurs by way of bioturbative and constructional activities of the mound-building termites, which in this study included Nasutitermes triodiae, Amitermes vitiosus, Drepanotermes rubriceps, Tumulitermes hastilis and T. pastinator. Termitaria from these species are mappable regolith– landform attributes at the local scale; this highlights their specific preferences for colony sites, such as access to vegetation, drainage, and the availability of construction materials. The mound-building termites featured in this study are also soil modifiers, altering the pedolith terms of both structure and chemistry. Developing an understanding of these processes has helped to refine a model for pedolith development through biotic processes, which is applicable to subtropical and tropical climatic regions, where termites act as important ecosystem engineers. This research project fills a niche for new scientific investigation of deeper regolith profiles and associated terrains; it moves away from theories of shallow soil development overlying an abiotic deep regolith, towards understanding pedolith development as wholly biotically driven. For mineral explorers this means that ore-related elements, such as Au, As and Zn, are re-organised and moved towards the land surface in settings such as buried Au-deposits and mineralisation in the Tanami region, and Pine Creek Orogen. A key finding within the study of the application of this technique is that the fine, silt-clay (>79 μm) from termitaria is capable of accurately delineating the surficial expression of buried Au mineralisation. Termitaria can therefore provide an accessible surficial biogeochemical sampling media that can be used in mineral exploration programs / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1369217 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2009

Submitted by Marly Aparecida da Silva (marliy.silva@yahoo.com) on 2018-07-05T14:47:20Z No. of bitstreams: 1 Prospecção geofísica em ocorrência de estanho associada ao Granito São Sepé (RS).pdf: 3205470 bytes, checksum: b43cd08a47eb517586499b5756d7ac66 (MD5) / Approved for entry into archive by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br) on 2018-07-05T16:47:13Z (GMT) No. of bitstreams: 1 silva_map_me_rcla.pdf: 3205477 bytes, checksum: e39798d0c3b2012293b8f8bad2c6cd4a (MD5) / Made available in DSpace on 2018-07-05T16:47:13Z (GMT). No. of bitstreams: 1 silva_map_me_rcla.pdf: 3205477 bytes, checksum: e39798d0c3b2012293b8f8bad2c6cd4a (MD5) Previous issue date: 2018-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho apresenta e discute os resultados gerados através de levantamentos geofísicos terrestres de Eletrorresistividade e da Polarização Induzida (IP) utilizados na investigação de uma ocorrência de estanho (cassiterita) associada a hidrotermalito do tipo greisen, localizada na borda oeste do Granito São Sepé. A área de estudo está localizada na porção central do Escudo Sul-Riograndense, município de São Sepé (RS). A ocorrência mineral está associada a veios de quartzo inseridos nos quartzos xistos do Complexo Metamórfico Vacacaí. Foram realizadas 6 linhas de caminhamento elétrico dispostas paralelamente na direção N30W. Os dados foram processados para elaboração dos modelos de inversão 2D gerados para os parâmetros de resistividade e cargabilidade. Os modelos de inversão 2D indicaram áreas de alta cargabilidade interpretadas como as prováveis zonas de concentração da cassiterita. Os dados de resistividade não foram suficientes para a definição das zonas mineralizadas, uma vez que a encaixante (quartzo-xistos) e os veios mineralizados apresentam valores de resistividade parecidos. Desse modo, os dados de cargabilidade foram utilizados para gerar os modelos de visualização 3D, os quais permitiram determinar a morfologia e a continuidade da provável zona de ocorrência da cassiterita. Os resultados dos modelos de visualização 3D mostraram que na área investigada ocorrem dois conjuntos de veios de quartzo e que os sulfetos ocorrem disseminados, provavelmente, nos veios com direção N30W. / This work presents and discusses the results generated by terrestrial geophysical surveys of DC resitivity and Induced Polarization (IP) used to investigate an occurrence of tin (cassiterite) associated with greisen type hydrothermalite, located on the western border of São Sepé Granite. The study area is located in the central portion of the Shield Sul-Riograndense, municipality of São Sepé (RS). The mineral occurrence is associated with quartz veins inserted in the schist quartz of the Vacacaí Metamorphic Complex. Six electric path lines were arranged parallel in the N30W direction. The data were processed to elaborate the 2D inversion models generated for the resistivity and chargeability parameters. The 2D inversion models indicated areas of high chargeability interpreted as the probable zones of concentration of cassiterite. The resistivity data were not sufficient for the definition of the mineralized zones, since the nesting agent (quartz-schists) and the mineralized veins presented similar resistivity values. Thus, the chargeability data were used to generate the 3D visualization models, which allowed to determine the morphology and continuity of the probable cassiterite occurrence zone. The results of the 3D visualization models showed that in the investigated area two sets of quartz veins occur and that the sulphides occur probably in the veins with direction N30W.