Ground Gravity Research Articles

Delineation of structural and tectonic features in the Mahanadi basin, eastern India: New insights from remote sensing and land gravity data

• An integrated analysis (ALOS PALSAR , SRTM-DEM, and Ground Gravity data) is performed to delineate the structural and tectonic framework at the Mahanadi graben , India. • The 2-D gravity model incorporates the rifting model of the basin formation along the preexisting basement shear zones. • The structural trends with pronounced geomorphic expressions represent the reactivated structures formed under the evolving stress regimes of the Mahanadi graben. During Gondwana dispersal, the Mahanadi basin experienced rifting and reactivation of preexisting structures, causing terrain deformation with faulting. The landform around Proterozoic Sukinda Thrust in the Mahanadi basin provides an opportunity to map the geomorphic expressions and correlate them with the tectonics of the graben using remote sensing images, digital elevation model, and gravity data. The subsurface extensions of the identified structures using SAR data and relief image analysis are modeled with the Bouguer gravity anomaly. The mapped tectonic features correlate well with the gravity gradient trends in residual gravity anomalies. The E-W and NW-SE trending residual gravity lineaments match well with the mapped faults and suggest their extension within the shallow crust. The two-dimensional (2-D) gravity model realistically constrains the subsurface geology, and by incorporating other published data, we suggest that the Gondwana rifting had reactivated the preexisting shear zones in the cratonic basement down to a depth of ∼ 5 km and subsequently deposited sediments into the fault-bound shallow basin of the Mahanadi graben.

Deep Crustal Structure of the Eastern Central Asian Orogenic Belt Revealed by Integrated Magnetic-Gravity Imaging

The Central Asian Orogenic Belt (CAOB) is a globally magnificent accretionary orogenic belt that has been formed since the Phanerozoic as a result of the Paleozoic closing of the Paleo-Asian Ocean (PAO). The transition zone between the North China Craton (NCC) and the Siberia Plate is located in the eastern CAOB and has been thoroughly investigated by various seismic investigations. However, other types of geophysical approaches lag behind, especially integrated magnetic-gravity surveying, which could provide regional continent-scale constraints on the deep crustal structure. Here, the high-resolution ground gravity and airborne magnetic data covering the study region are newly processed by upward continuation, an improved potential field normalization differential algorithm, an analytical signal approach, and correlation analysis. The processed gravity and magnetic anomalies reveal dominant differences between the CAOB and the northern margin of the NCC; these regions are tectonically divided by the upper crustal Chifeng-Baiyan Obo fault, which is expressed by an important geological boundary. In the middle and lower crust, this tectonic boundary extends northward to the Xar Moron fault. Unexposed Mesozoic granites may be distributed extensively in the mid-lower crust along the Solonker suture zone. The local negative correlation characteristics of gravity and magnetic anomalies may be related to the structural fabrics derived from the convergence of the two terrains.

Potential field data interpolation by Taylor series expansion

Data interpolation is critical in the analysis of geophysical data when some data are missing or inaccessible. We interpolate irregular or missing potential field data using the relation between adjacent data points inspired by the Taylor series expansion (TSE). The TSE method first finds the derivatives of a given point near the query point using data from neighboring points and then uses the Taylor series to obtain the value at the query point. The TSE method works by extracting local features represented as derivatives from the original data for interpolation in the area of data vacancy. Compared with other interpolation methods, the TSE provides a complete description of potential field data. Specifically, the remainder in TSE can measure local fitting errors and help obtain accurate results. Implementation of the TSE method involves two critical parameters — the order of the Taylor series and the number of neighbors used in the calculation of derivatives. We find that the first parameter must be carefully chosen to balance between the accuracy and numerical stability when data contain noise. The second parameter can help us build an over-determined system for improved robustness against noise. Methods of selecting neighbors around the given point using an azimuthally uniform distribution or the nearest-distance principle are also presented. Our approach is first illustrated by a synthetic gravity data set from a single survey line, and then it is generalized to the case over a survey grid. In both numerical experiments, the TSE method demonstrates an improved interpolation accuracy in comparison with the minimum curvature method. Finally, we apply the TSE method to a ground gravity data set from the Abitibi Greenstone Belt, Canada, and an airborne gravity gradient data set from the Vinton Dome, Louisiana, USA.

Heater size and gravity level effects on nucleate pool boiling heat transfer under controlled wall heat flux condition

With the ability of dissipating large amount of latent heat in nearly isothermal process, pool boiling heat transfer is an efficient solution for cooling problem of different sized electronic devices in different gravities. For the practical heat dissipation of electronic device usually occurs at controlled wall heat flux condition, it is essential to reveal pool boiling heat transfer characteristics at different sizes and gravities under controlled wall heat flux condition. In this paper, boiling heat transfer mechanisms on two sized smooth silicon chips (chip S 1 × 1 and chip S 2 × 2) in ground gravity and microgravity were studied. It was found that the gravity scaling parameters developed under controlled wall temperature condition cannot be applicable to the controlled wall heat flux condition. Under controlled wall heat flux condition, the microgravity boiling heat transfer performance on chip S 1 × 1 is in surface tension dominated boiling (SDB) regime in the whole heat flux range. While for chip S 2 × 2, it is in SDB regime when heat flux is smaller than 6.44 W·cm−2, but enters into buoyancy dominated boiling (BDB) regime when heat flux is larger than 6.44 W·cm−2. The critical point of the two boiling mechanisms occurs when the threshold gravitational acceleration equals to the experimental microgravity. In BDB regime, the power law coefficient reflecting the gravity effect on nucleate boiling heat transfer performance (mBDB) for controlled wall temperature condition is larger than that for controlled wall heat flux condition, indicating a greater impact of gravity level under controlled wall temperature condition. Moreover, mBDB for controlled wall temperature condition is affected only by non-dimensional wall temperature T*. While for controlled wall heat flux condition, mBDB increases with increasing T* but decreases with increase in heater size, and heater size has a greater influence on mBDB. Based on the available data, the gravity scaling parameters for controlled wall heat flux boiling were developed, which can accurately predict the microgravity boiling heat transfer performance on two sized chips.

High-Resolution Density Joint Inversion Method of Airborne and Ground Gravity Data With Cross-Constraint Technique

The airborne gravimetry measurement can better highlight the anomalous response of deeper resources than ground gravity data, so an integrated survey of airborne and ground gravity data is an effective strategy to obtain the obvious response of shallow and deep mineral resources simultaneously. In order to obtain a more reliable and higher resolution 3-D density distribution model through the joint inversion of airborne and ground gravity data to support deeper source exploration, we propose a high-resolution joint inversion method with a cross-constraint technique. We use structural constraints to establish an objective function for joint inversion of airborne and surface gravity data, and add density-weighting constraints through cross-calculation to make full use of the sensitivity of different data and geological targets. Synthetic model tests prove that the cross-constraint joint inversion method of airborne and ground data improves the model resolution effectively, and can delineate the distribution of deeper targets more clearly compared to the existing joint inversion way. In order to predict the spatial distribution of deep ore-bearing rock bodies in a north Qinling area of Shaanxi province, we obtained regional measured airborne and surface gravity data. High-resolution density joint cross-constraint inversion method was used for real data interpretation, and the distribution feature of possible deep ore-forming rock bodies.

Сравнение глобальных моделей гравитационного поля на территории Магаданской области

The global databases of gravity anomalies, currently available to researchers, provide a new informative tool for constructing density models of the deep structure of the earth's crust for individual regions. Currently, there are six models of gravitational anomalies, presented as a series of spherical harmonics up to 2190 degrees, which corresponds to about 10 km on the earth's surface. Different methods of processing terrestrial, marine, aerial, and satellite gravimetric data, available to their authors, determine the differences between these models, both on a global scale and within specific regions. We have performed a comparison of the EGM2008, GECO, EIGEN-6C4, and WGM2012 models with the Gravimag database on the Magadan Oblast territory. The comparison showed that free air anomalies for the EGM2008, GECO, EIGEN-6C4, and WGM2012 models in the selected area almost coincide. Bouguer anomalies of the WGM2012 model can be used in regional density modeling for adjacent regions where there are no conventional ground gravity data; however, within Magadan Oblast the Gravimag database has the best data quality.

Quantitative depth estimation using analytic signal at low-latitude for ground gravity survey of Gbede, Oyo State

This paper presents the insitu gravity survey of basement complex rock in Southwestern Nigeria. In the E-W direction, LaCoste and Romberg Gravity Meter type G309 was used to carry out a ground gravity survey where ten traverses were established over a distance of 1000 m by 500 m with station spacing of 20m and a traverse interval of 50 m. Observed gravity values were corrected, analyzed and interpreted quantitatively. The corrected bouguer gravity data were presented as bouguer anomaly graphs. Analytic Signal at low-latitude was adopted to compute the depth to source of iron-ore for a contact, a thin sheet (dyke) and a horizontal cylinder. The result revealed a depth range of 5.45 m-8.25 m for a contact, 9.44 m-14.29 m for a thin sheet (dyke) while a depth range of 12.31 m-18.05 m was estimated for a horizontal cylinder respectively. An average depth of 11.81±3.64 m was estimated for the entire area irrespective of the structural model, this was compared with published magnetic results of the study area and a small disparity of potential field measurements was recorded. The overall computed results signified the existence of iron mineral deposits at low depths across the study area.

The geophysical signature of Oyut deposits, Oyu Tolgoi, Mongolia

The well-known Oyu Tolgoi Cu-Au group deposits can be divided into three main deposits: Hugo Dummett deposit (Hugo North and Hugo South), Oyut deposits (South Oyu, Southwest Oyu and Central Oyu), and Heruga deposit in the south. These deposits sit along 26 km long, north-northeast trending belt termed as the Oyu Tolgoi trend. This paper reviews investigations on geophysical signatures of the South Oyu, Southwest Oyu and Central Oyu deposits and compares geophysical models of the mineral deposits with their lithology, alteration, mineralization, and structures. A variety of datasets including induced polarization, ground magnetic, gravity survey are used in the study and generated inversion products of ground magnetic and gravity data with integrated interpretation. Typical responses from the Oyut deposits are: up to 0.1 mGal positive gravity anomaly above background, 100–200 nT low or high magnetic anomaly compared to background depending on the geological situations, and from 12 mV/V to 30 mV/V chargeability anomalies and low resistivity signatures from 100 ohm.m to 400 ohm.m. The interpreted geological-geophysical models of porphyry Cu-Au deposits presents in this study have emphasis on integrated interpretation of geophysical techniques, and inversions of gravity and magnetic data in gold rich porphyry copper system.

The influence of gravity load on the accuracy of mesh reflector antenna

Space large deployable mesh antennas are the focus of research in the aerospace field. There is a high requirement for the reflector surface accuracy of the mesh antenna in orbit. Due to the low stiffness of the truss cable net system, the deformation of the flexible mesh surface under the ground gravity load cannot be ignored. Therefore, it is the key technology to ensure the accuracy of on orbit cable network reflector that accurately predict the difference of reflector under gravity load and microgravity load. This study establishes the mechanical model of the cable-truss system. The Newton Iterative Method is used to solve the nodal nonlinear equilibrium equation in the gravity load, and the deformation of the antenna mesh surface under the gravity load is obtained.

Joint inversion of ground gravity data and satellite gravity gradients between Nepal and Bhutan: New insights on structural and seismic segmentation of the Himalayan arc

Along-strike variation in the geometry of lithospheric structures is a key control parameter for the occurrence and propagation of major interplate earthquakes in subduction and collision zones. The lateral segmentation of the Himalayan arc is now well-established from various observations, including topography, gravity anomalies, exhumation rates, and present-day seismic activity. Good knowledge of the main geometric features of these segments and their boundaries is thus the next step to improve seismic hazard assessment in this area. Following recent studies, we focus our approach on the transition zone between Nepal and Bhutan where both M > 8 earthquakes and changes in the geometry of the Indian plate have been documented. Ground gravity data sets are combined with satellite gravity gradients provided by the GOCE mission (Gravity Field and Steady-State Ocean Circulation Explorer) in a joint inversion to assess the location and the geometry of this transition. We obtain a ca. 10 km wide transition zone located at the western border of Bhutan that is aligned with the Madhupur fault in the foreland and coincides with the Dhubri–Chungthang fault zone and the Yadong-Gulu rift in Himalaya and southern Tibet, respectively. This sharp segment boundary at depth can act as a barrier to earthquake rupture propagation. It can possibly restrict the size of large earthquakes and thus reduce the occurrence probability of M > 9 earthquakes along the Main Himalayan Thrust.

Delineation of structure elements and the basement depth at the Jifara plain NW LIBYA using integration application of potential field dataset

In this study, the analysis of ground gravity data (from the Libyan Petroleum Institute) and aeromagnetic data (from the African Magnetic Mapping Project) are used to delineate the structure elements and basement depth within the Jifara plain, northwest Libya. A high-pass filter and a reduction-to-the-pole (RTP) transformation are applied to the gravity and aeromagnetic data respectively. The Total horizontal gradient and Centre for Exploration Targeting (CET) grid analysis are applied to gravity datasets. Werner deconvolution is applied to the RTP magnetic data. One 2-D forward modelling profile is applied to gravity and magnetic dataset. The results show gravity anomaly highs and magnetic anomaly with different structure trends. Werner deconvolution profile shows a high-density intrusion (about 1.8 km from the surface) within the sedimentary sequence. The intrusion may be the result of the Eocene volcanic activities near the Gharyan region. The 2-D model shows that the basement depth of Jifara plain ranges from 2.8 to 3.0 km. The integration results of the gravity and magnetic dataset reflect various periods of tectonic activities within Jifara plain and the adjacent area.

Appraisal of Veldurti–Kalva–Gani (VKG) fault, Cuddapah Basin, India: Gravity and magnetic approach

A ~60 km long Veldurti–Kalva–Gani (VKG) fault is one of the identified strike-slip faults extending from Eastern Dharwar Craton (EDC) to Cuddapah basin in South Indian Shield. The recorded recent seismic activity during year 2012–2016 show occurrences of three microseismic events (< Mw 2.0) in the vicinity of this fault. Historically, no major seismic events are recorded near this fault except magnitude of 5.0–5.9 (1843) earthquake at about ~80 km west of this fault near Bellary. In the present study, analysis of available gravity, aeromagnetic and newly acquired ground gravity and magnetic data in the vicinity of the fault has been carried out to understand subsurface characteristics of this VKG fault and nearby structural features related to recent seismic activity. Analysis of aeromagnetic and gravity data shows shallow origin of the fault and earthquakes are associated with the zone of intersection like cross faults/lineaments which are parallel and perpendicular to the VKG fault. The calculated log normalized radially averaged power spectrum of the available gravity and aeromagnetic data shows four average depths h0 (12.7 km), h1 (6 km), h2 (2.0 km) and h3 (0.5 km). These estimated depths are possibly, bottom of the upper crust, thickness of the Cuddapah basin sediments, horizon of the basic sills, flows and the ferruginous quartzites and cumulative stratigraphic thickness of the Tadpatri shales and the Kurnools in the areas, respectively. The jointly inverted 2-D model from the ground gravity and aeromagnetic data along 2.7 km profile across VKG fault shows, faulting between Banganapalli Quartzite and Tadpatri Shales. The estimated average focal depth from the observed microseismic events is around 13 km. It is concluded from the present study that the observed microseismic events in the vicinity of VKG fault are associated with the intersection zones of cross faults/lineaments near the VKG fault and originated at an average depth of 13 km might be bottom of the upper crust. The estimated depths from the present analysis are well corroborated with previous geophysical studies.

Magnetic and gravity investigation of kimberlites in north-central Botswana

The Orapa kimberlite field of Botswana is one of the world’s major diamond producing regions. Within this field, there are several small kimberlite pipes that have not been completely explored in terms of their lateral extent, depth, and diamond potential. Two such pipes, BK54 and BK55, were found during a ground gravity and magnetic survey, and subsequent drilling confirmed the presence of kimberlite material. To determine the physical properties of these pipes, their lateral extent, depth, and thickness were estimated using a gravity and magnetic analysis and 2.5D and 3D modeling. Tilt derivatives of the magnetic data indicated that BK54 has a northwest-trending elliptical shape and BK55 has a roughly circular shape. Residual gravity anomaly maps indicate that BK54 does not have a density anomaly whereas BK55 is associated with a gravity maximum. The 3D gravity and magnetic inversion modeling constrained by magnetic susceptibility measurements indicates that BK54 is smaller in volume than BK55 and that neither pipe is thicker than 125 m. The difference in shape and the lack of a gravity anomaly over BK54 implies a different formation mechanism for each kimberlite pipe. Although several mechanisms are suggested, BK54 may have formed by a more explosive eruption producing more tuffistic material in the crater and diatreme facies. The gravity and magnetic analysis also found that the kimberlite pipes, while small, are larger in extent than was determined by drilling and warrant additional drilling to determine their economic potential.

Analysis of gravity and aeromagnetic data to determine structural trend and basement depth beneath the Ajdabiya Trough in northeastern Libya

In this study, we analyse both ground gravity and aeromagnetic data in order to delineate structural trends, fault systems and deduce sedimentary thicknesses within the Ajdabiya Trough in Libya’s northeast. A high-pass filter and a reduced-to-the-pole (RTP) transformation are applied to the gravity and aeromagnetic data respectively. Different filters are used to enhance the structural signatures and fault trends within the study area. The Werner deconvolution and source parameter imaging (SPI) techniques are applied to the RTP magnetic data for source depth estimation. Four well-data within the area are used as constraints in the two-dimensional forward modelling process. The results show that the Ajdabiya Trough is characterised by gravity anomaly highs and magnetic anomaly lows. The analysis of gravity data shows predominant Northeast–Southwest structural trends, whereas the analysis of magnetic data shows predominant North–South magnetic lineaments within the Ajdabiya Trough. The Euler deconvolution depth estimates of faults depths range between 1500 and 9500 m. The SPI estimates of the magnetic basement range between 2500 and 11,500 m beneath the study area (deepest beneath the Ajdabiya Trough). Constrained by the well-data, six major layers characterize the four profiles that are taken within the area. One of the profiles shows a high-density intrusion (about 4 km from the surface) within the sedimentary sequence. The intrusion may be the result of the rifting Sirt Basin which caused a weakening of the crust to allow for mantle intrusion.

Integrated geophysical imaging of rare earth element-bearing iron oxide-apatite deposits in the Eastern Adirondack Highlands, New York

The eastern Adirondack Highlands of northern New York host dozens of iron oxide-apatite (IOA) deposits containing magnetite and rare earth element (REE)-bearing apatite. We use new aeromagnetic, aeroradiometric, ground gravity, and sample petrophysical and geochemical data to image and understand these deposits and their geologic framework. Aeromagnetic total field data reflect highly magnetic leucogranite host rock and major structures that likely served as fluid conduits for the hydrothermal system. Band-pass filtering of the aeromagnetic data reveals locations of individual deposits that were verified in the field or from historical records. A 3D inversion for magnetic susceptibility images these deposits at depth, allowing the inference of plunge directions and relative size. Radiometric data highlight variations in the surface geology and several large tailings piles that contain REE-bearing apatite. Within the host rock, eTh (equivalent Th), K, and the eTh/K ratio are variable with high eTh/K near several of the IOA deposits. Areas with elevated K or low eTh/K representing potassic alteration appear to be rare; instead, elevated eTh/K ratios likely reflect widespread sodic alteration that overprinted potassic alteration. Bouguer gravity anomalies show limited correspondence to the surface geology, radiometric data, or magnetic data, but they do exhibit approximately 10 km wide highs in areas where deposits are observed. Some 2D forward models of the gravity and magnetic data show that deeper dense material beneath the leucogranite is quantitatively feasible. If these dense rocks represent intrusions that were emplaced or still cooling at the time of mineralization, they may have served as a heat source that helped to drive the hydrothermal system. Combining data sets, we find that deposits occur toward the distal ends of major structures within the host leucogranite and mostly above gravity highs. The geophysical modeling thus suggests that IOA deposits formed in structural, thermal, and chemical traps near the distal ends of the hydrothermal system.

Bouguer anomaly inversion and hydrocode modeling of the central uplift of the Araguainha impact structure.

Araguainha is a mid-sized complex impact structure formed in sedimentary and underlying basement rocks of the Paraná Basin, Brazil. The structure has strongly deformed sedimentary strata surrounding a granitic core. The central uplift is a region of high geological complexity, comprising different types of sedimentary, igneous (granite) and metamorphic lithologies, plus breccias and impact melt sheets. New ground gravity data was collected to produce a Bouguer anomaly map and to perform a 3-D inversion in order to obtain a 3-D density model of the central uplift. This 3-D density model is consistent with iSALE numerical modeling results, which shows that the rocks in the innermost portion became brecciated and/or melted after undergoing pressure/temperature peaks. The positive anomaly of Furnas and Ponta Grossa formations associated with the numerical model shows that the central uplift is ~16 km wide. Thus, the granite's uplift caused the uplift of the entire stratigraphic package, from its Devonian-aged units to the Permian ones, forming a bull's eye pattern around the granitic core. The results also indicate that Araguainha was formed by a 3 km diameter impactor, and the rocks of the granitic basement rocks were uplifted by ~2 km.

Columnar vortices induced by dielectrophoretic force in a stationary cylindrical annulus filled with a dielectric liquid

Abstract

Multigeophysical data integration using cluster analysis: assisting geological mapping in Trøndelag, Mid-Norway

SUMMARY Modern geophysical data acquisition technology makes it possible to measure multiple geophysical properties with high spatial density over large areas with great efficiency. Instead of presenting these co-located multigeophysical data sets in separate maps, we take advantage of cluster analysis and its pattern exploration power to generate a cluster map with objectively integrated information. Each cluster in the resulting cluster map is characterized by multigeophysical properties and can be associated with certain geological attributes or rock types based on existing geological maps, field data and rock sample analysis. Such a cluster map is usually high in resolution and proven to be more helpful than single-attribute maps in terms of assisting geological mapping and interpretation. In this paper, we present the workflow and technical details of applying cluster analysis to multigeophysical data of a study area in the Trøndelag region in Mid-Norway. We address the importance of carefully designed pre-processing procedures regarding the input data sets to ensure an unbiased data integration using cluster analysis. Random forest as a supervised machine learning method for classification/regression is strategically employed post-clustering for quality evaluation of the results. The multigeophysical data used for this study include airborne magnetic, frequency electromagnetic and radiometric measurements, together with ground gravity measurements. Due to the nature of these input data, the resulting cluster map carries multidepth information. When associated with available geological information, the cluster map can help interpret not only bedrock outcrops but also rocks underneath the sediment cover.

Crustal and thermal structure of the Permian – Jurassic Luangwa – Lukusashi – Luano Rift, Zambia: Implications for strain localization in magma – Poor continental rifts

This work uses aeromagnetic, satellite gravity, and ground gravity data to image the thermal and crustal structures beneath the NE-trending Paleozoic - Mesozoic Luangwa – Lukusashi – Luano (LLL) rift in southeastern Zambia. This rift extends between the Precambrian Irumide metacraton in the northwest and the Niassa craton to the southeast and is partially controlled by the NE-trending Mwembeshi suture zone between the two blocks. Although the LLL rift is suggested to have been reactivated by the Southwestern Branch (SWB) of the East African Rift System (EARS), this work did not find shallowing of Curie Point Depth (estimated from the spectral analysis of aeromagnetic data) that would be indicative of elevated heat flow beneath the rift. Three-dimensional inversion of the aeromagnetic data shows a number of magnetized bodies, the largest occurring beneath the central part of the LLL rift and extending to a depth of ~35 km. Spectral analysis of the satellite gravity data indicates a ~45 km thick crust beneath the southwestern and central parts and the northeastern tip of the LLL rift. Two-dimensional (2D) forward modeling of the ground gravity data indicates a ~200 km wide and ~12 km thick under-plated mafic body (UPMB). These results support limited reactivation of the LLL rift by the SWB of the EARS. Further, extensional strain localization during the onset of the LLL rifting is attributed to the accretion of the UPMB beneath the crust.

Mapping New IOCG Mineral Systems in Brazil: The Vale do Curaçá and Riacho do Pontal Copper Districts

The Vale do Curaçá and Riacho do Pontal copper districts are located within the northern part of the Archaean São Francisco Craton and represent two pulses of mineralization. The copper districts have been identified as Iron-Oxide-Copper-Gold (IOCG) classes of deposits. An older metallogenic event associated with the Caraíba copper deposit, which is located in the Vale do Curaçá district, is related to Palaeoproterozoic (ca. 2 to 2.2 Ga) hydrothermal processes. A younger Neoproterozoic (ca. 750 to 570 Ma) episode of volcanism and associated plutonism is represented by the Riacho do Pontal mineral district. Seismic tomography data from across east-central Brazil show that the multiage Carajás province and Vale do Curaçá and Riacho do Pontal copper districts sit along either side of a prominent NW-trending upper lithospheric high-velocity zone. The edges of the high-velocity zone point to long-lived subparallel transcrustal structures that have been the focus of multiple reactivations and copper mineralization events. Regional gravity and magnetic maps show that the Vale do Curaçá copper district extends over an area greater than 110 km by 22 km. The magnetic and gravity values show significant variations correlated with this area. The district includes high gravity values associated with the Caraíba copper mine (&gt;−35 mGal), which has a greater density (3.13 g/cm3) than the nonmineralized host rock density (2.98 g/cm3). The gravity anomaly signature over the Riacho do Pontal copper district is characterized by a 40-km long NW–SE trending Bouguer gravity low. The Ria4 occurrences of the Riacho do Pontal copper district are situated in these regional low-gravity domains. Data from regional airborne magnetic and ground gravity surveys were inverted to obtain a 3D magnetic susceptibility and density model, respectively, for the known districts. The results show that the Caraíba deposit is characterized by a both dense and magnetic source showing structural control by thrust shear zones. The 2D and 3D geological models show two main NNW prospective trends. Trends I and II have a sigmoidal shear shape and are positioned in the contact zone between domains with high magnetic susceptibility (SI &gt; 0.005) and density &gt; 0 g/cm3). Trend I is 40 km × 10 km in size and hosts the Caraíba, Surubim, and Vermelho copper mines and other minor deposits. The results obtained from the 3D magnetic inversion model for the region of the Riacho do Pontal district show weak magnetic anomaly highs extending along a NW–SE magnetic gradient trend. The gradient is related to mapped shear zones that overprint older and deeper NE–SW features of the São Francisco cratonic root. The area includes high gravity values associated with the Caraíba copper deposit, which has a greater density (3.13 g/cm3) than the nonmineralized host rock density (2.4 g/cm3).