Euler Deconvolution Technique Research Articles

Application of Euler and Werner deconvolution techniques in delineating tin deposit in Okeso area, Southwestern, Nigeria

The Okeso pegmatites field was evaluated using magnetic method within abandoned mining site close to the southeastern region of Ojoku area. The study aims to delineate, identify geological boundaries and determine depth of tin deposits in the area. The acquired magnetic data was enhanced with the combination of 3D Euler and Werner deconvolution methods. Five magnetic profiles were selected and carried out on the residual anomalies around the abandoned mine site at Okeso with three of the profile lines were in the NW-SE direction and two in the NE-SW direction. The residual magnetic anomalies showed the magnetic susceptibilities of ≤ 4.5118 × 10−3 nT in the ore bearing pegmatite within the basement rocks. Results from profiles of Werner deconvolution identified some shallow tectonic structures like fractures, pegmatites and faults which are capable of hosting metallic tin deposits. The depth to the magnetic source varies from a minimum to a maximum of 300 m to 1200 m below the subsurface in all selected profiles, suggesting the shallow nature of the magnetic source in the area. Additionally, the dip angle ranges from 5.60 to 81.20, potentially attributed to Pan-African shallow structures according to the contact model. Solutions obtained from the structural index of contact and dyke reveals the presence of dyke formation and boundaries which separate rocks from one another. The trend of the lineaments/ fractures which were likely established during the Pan-African orogeny is dominant in the NE-SW direction, conforms with the trends obtained for basement structures in previous studies. Depth range produced by 3D Euler deconvolution is from 50 - 1000 m for all the lineaments. This gives an insight of approximate depth range of all the lineaments/ fractures across the whole map in the study area unlike, Werner deconvolution which is profile biased. The identical signature from all profiles implies that the tin deposit is relatively uniform, extending to a great depth in the area. This represents economically viable quantity and makes it a worthy target for investors.

Application of Euler and Werner deconvolution techniques in delineating tin deposit in Okeso area, Southwestern, Nigeria

The Okeso pegmatites field was evaluated using magnetic method within abandoned mining site close to the southeastern region of Ojoku area. The study aims to delineate, identify geological boundaries and determine depth of tin deposits in the area. The acquired magnetic data was enhanced with the combination of 3D Euler and Werner deconvolution methods. Five magnetic profiles were selected and carried out on the residual anomalies around the abandoned mine site at Okeso with three of the profile lines were in the NW-SE direction and two in the NE-SW direction. The residual magnetic anomalies showed the magnetic susceptibilities of ≤ 4.5118 × 10−3 nT in the ore bearing pegmatite within the basement rocks. Results from profiles of Werner deconvolution identified some shallow tectonic structures like fractures, pegmatites and faults which are capable of hosting metallic tin deposits. The depth to the magnetic source varies from a minimum to a maximum of 300 m to 1200 m below the subsurface in all selected profiles, suggesting the shallow nature of the magnetic source in the area. Additionally, the dip angle ranges from 5.60 to 81.20, potentially attributed to Pan-African shallow structures according to the contact model. Solutions obtained from the structural index of contact and dyke reveals the presence of dyke formation and boundaries which separate rocks from one another. The trend of the lineaments/ fractures which were likely established during the Pan-African orogeny is dominant in the NE-SW direction, conforms with the trends obtained for basement structures in previous studies. Depth range produced by 3D Euler deconvolution is from 50 - 1000 m for all the lineaments. This gives an insight of approximate depth range of all the lineaments/ fractures across the whole map in the study area unlike, Werner deconvolution which is profile biased. The identical signature from all profiles implies that the tin deposit is relatively uniform, extending to a great depth in the area. This represents economically viable quantity and makes it a worthy target for investors.

Economic feasibility of Gabal Um Takha leucogranitic intrusion, South Sinai, Egypt: Integrated remote sensing, geochemical, aeromagnetic, and geotechnical approach

Variable granitic rocks are widely used as decorative stones. The present work conducted accurate mapping and the utilization of a large leucogranitic intrusion (Um Takha area) as a decorative stones through physico-mechanical tests, mineralogical and geochemical compositions. These leucogranites are medium-grained, classified as syenogranites, peraluminous, calc-alkaline, and highly evolved granites developed during the post-collisional setting. This study utilized various remote sensing techniques to identify the Um Takha leucogranitic using ASTER and Landsat-9 data. A novel FCC band ratio of the ASTER image (RGB: b1+b3/b2, b2/b1, b7+b9/b8) was created, along with the Landsat-9 FCC band ratio of (4/7, 3/4, and 2/1) in the RGB, to effectively map the distribution of in the study area. These results, combined with field observation, led to the creation of a new modified geological map of the Um Takha area. The analysis of magnetic data reveals that the depth of magnetic sources under the study area ranges between 170 m and 2215 m, as calculated by source parameter image and Euler deconvolution techniques. The application of horizontal gradient, tilt derivatives and improved logistic techniques reveals that the major structural trend affecting the study area is in the N–S, NNE-SSW and NNW-SSE direction. The physico-mechanical properties of leucogranitic rocks (M13) fulfilled the requirements of dimension stone in terms of bulk density, compressive strength, and to some extent water absorption. Therefore, they could be acceptable for interior use and the light-duty purposes of exterior use, such as facades and cladding. This suggest that a large resources of leucogranitic can be used as a decorative stones.

Interpretation of the tectonic structure of Gemlik Bay using magnetic data

The aim of this study was to determine the effects of the main faults and many small-scale faults and submarine structures within Gemlik Bay, on the middle strand of the North Anatolian Fault in the southeast of the Sea of Marmara. In order to produce a fault map for the study area and research tectonic structures, magnetic data were obtained using a cesium vapor magnetometer on a total of 30 profiles (340 km) with N-S and E-W orientation within the bay. Diurnal corrections were applied to obtain the necessary minimization of diurnal variations in the magnetic data. Heading correction and micro-leveling corrections were applied to remove small boat effects, and the reduction to the pole method was applied for greater differentiation of the magnetic data. Magnetic data were analyzed using advanced potential field processing techniques. Euler deconvolution technique was applied to define the extension and depth of the determined lineaments. Boundaries of structures in the region were determined using source edge detection, tilt derivative, the tilt angle of the total horizontal gradient amplitude (TAHG), and a novel edge detector based on the softsign function (SF) techniques. In order to reveal the tectonic evolution of Gemlik Bay, the structures obtained from the analysis results were interpreted and a fault map was produced. The results of the study identified the Armutlu Fault in the north, the Gemlik Fault in the east, the Zeytinbağı Fault and Mudanya Fault in the southwest and the Gençali Fault in the south within Gemlik Bay. These five essential faults significantly affected the region tectonically. These faults correlated well with the location of some previously-known major tectonic structures. Moreover, these important faults following the morphology of the bay indicate that Gemlik Bay was opened by a pull-apart basin mechanism.

An Application of Softsign Function (SF) Filter to Low-Latitude Aeromagnetic Data of Tafawa-Balewa Area, Northern Nigeria for Geostructural Mapping and Tectonic Analysis

A recently proposed edge detection technique – Softsign Function (SF) filter was applied to a synthetic magnetic data to illustrate its application. It was then applied in combination with 3D Euler deconvolution and 2D magnetic modelling techniques to the low-latitude aeromagnetic data of Tafawa-Balewa Area, Northern Nigeria, aimed at subsurface geostructural mapping and tectonic analysis of the study area. This was corroborated with mapping and analysis of surface lineaments from Landsat-9 image of the study area. The SF filter depicted edges of magnetic sources from the synthetic magnetic and aeromagnetic data as distinct peaks. The 3D Euler deconvolution solutions and 2D magnetic model showed two dominant depth ranges ∼ 10 m to ∼ 400 m (D1) and ∼ 400 m to ∼ 1000 m (D2) of magnetic sources. The subsurface and surface lineaments from the aeromagnetic data and Landsat-9 image, respectively, fairly agreed in location, trends, even distribution, and density. The trends of mapped lineaments are majorly ENE – WSW direction, and the minor trends are WNW – ESE, NE – SW, NNW – SSE, NNE – SSW, and NW – SE directions. These linear structures, consistent with regional tectonics, are suspected to be strike-slip faults generated by the conjugate system of strike-slip NE – SW and NW – SE faults, including the Romanche and Chain fault systems, produced by the oceanic-continental transcurrent movements which affected the Nigerian basement complex. Explicitly, Softsign Function (SF) filter is a valuable edge detection technique in mapping geological structures from a real low-latitude aeromagnetic data reduced to the geomagnetic equator for tectonic analysis.

Hydrocarbon reservoir depth identification in the eastern black sea basin: Implications from euler deconvolution and gravity tensor invariants

The Black Sea Basin (BSB) consisting of Eastern Black Sea (EBS) and Western Black Sea (WBS) basins which separated by the Mid Black Sea High (MBSH) is formed by the collision of Eurasia and Arabian-African Plates. Petroleum and gas hydrate contents of the BSB have been discussed by using different geological and geophysical research. In this study, the gravity gradient tensor and invariant data based on the Bouguer gravity anomaly of the EBS basin were evaluated to define the hydrocarbon reservoirs. Afterwards, Euler deconvolution technique is applied to the invariant to reveal the depth of subsurface bodies. Furthermore, the significant invariant anomalies are compared with known oil seepage and petroleum wells. The depth values of oil trace closest to the known Sürmene and Hopa drill holes were computed as 4809 m, and 4455 m according to the structural index values of SI = 2.

Aeromagnetometric data aplication to investigate the magnetic basement - Caçapava do Sul, RS

The evolution and understanding of the granitic intrusive rock structures in the southern Rio Grande Shield (SRGS) are fundamental to supporting the investigation of mineral occurrences in the state of Rio Grande do Sul, Brazil. This mineral province is classified as complex with igneous, metamorphic, and sedimentary rocks of the Archean to Neopaleoproterozoic age. The main objective of the present study was to investigate the Caçapava do Sul Shear Zone (CSSZ), of which, despite its role as a terrain boundary, its kinematic importance at a regional scale is still questioned. With this objective, aeromagnetometry data were used to enhance the lineaments, trace the domains and estimate the depth of the basement surface related to the formation of the Caçapava do Sul Granitic Complex (CSGS) and consequently the CSSZ. In addition, 3D Euler deconvolution and Source Parameter Imaging (SPI) techniques were applied to estimate the depth of the magnetic basement surface. The 3D Euler deconvolution provided the estimated depth of structural features internal and external to the CSGS. Among the identified features, they include the transcurrent shear zones located at the internal boundaries of the CSGS associated with the tectonic evolution of the granitic body. The joint interpretation of the SPI technique with the 3D Euler deconvolution evidenced the influence of the CSSZ on the magnetic basement, showing even less influence of this feature on its southwestern limits (decrease in the depth of the magnetic basement). This work, through the application of enhancement techniques, evidenced the influence of the Shear Zones on the surface of the magnetic basement. In this way, the results found in this work provide subsidies with greater weights for future geological mappings and studies focused on the evolution of the CSGS.

Using Airborne Geophysical and Geochemical Methods to Map Structures and Their Related Gold Mineralization

Egypt’s mineral resources are an effective means of raising the country’s income. Consequently, searching for deep subsurface ore deposits is essential. In this study, we map the subsurface structure and the occurrence of related gold-ore mineralization deposits in ophiolitic-assemblage rocks around the Wadi El-Saqia area in the Central Eastern Desert of Egypt. Our approach combines airborne geophysical data (aeromagnetic mapping) and geochemical analyses. We enhanced the aeromagnetic data and interpreted them using edge-detection methods, such as the first-order vertical derivative (FVD), the analytic signal (AS), the total horizontal derivative (THD), the tilt derivative (TD), the tilt angle (TA), the theta map, both grid and porphyry analyses from the Centre for Exploration Targeting (CET), and Euler deconvolution (ED) techniques. Utilizing these methods, we located the main structural lineaments/contacts that control the distribution of hydrothermal alteration zones. In addition, our geochemical analyses use the mineral chemistry of pyroxene and plagioclase to describe their tectonic and magmatic evolution. The airborne geophysical results revealed that NW–SE, NE–SW, N–S, and E–W structural orientations are prevalent in the studied area, with depths ranging from less than 50 m to about 600 m. To validate the findings, we carried out geochemical sampling, which indicates that pyrite, galena, pyrrhotite, and electrum contain good percentages of gold (ranging from 0.01–0.09 wt%, 0.03–0.1 wt%, 0.12–0.14 wt%, and 53.55–55.01 wt%, respectively). In this study, we were thus able to find preferred locations for gold mineralization, which highlights the value of combining aeromagnetic and geochemical data for mineral exploration.

Investigation of the Gravity Anomalies within Brass and Environs, Niger Delta Area, Nigeria: Implications for Hydrocarbon Prospectivity

The airborne gravity data over Brass Area and environs, Niger Delta Area, Nigeria were processed and interpreted in order to delineate the sedimentary thickness within the basin and map out places with the potentials for hydrocarbon formation, accumulation and migration. The geological structures, depths andstructural trends within the area were investigated using Total Horizontal Gradient, Tilt Derivative, Analytical Signal Filters and Euler Deconvolution techniques. The results from Euler depths showed that the sedimentary thickness and structural depths within the area range from about 1.6 to over 17.4 km.The area predominantly has NE-SW structural trend with minor NW-SE trend.The sediment thickness and structural endowment of the area prompted the classification of Egeregere, Brass, Spiff Town, Kirikakiri Areas in the northern and the southern partsof the area as zones of very viable potentials for hydrocarbon generation, accumulation and migration.

A reconnaissance study for tracing and ordering new mineralisation zones using integrated remote sensing, GIS, and aeromagnetic techniques, west Allaqi-Heiani-Suture,Egypt

ABSTRACT Reducing expenses is a critical aspect of natural resource explorations, especially in the reconnaissance stage. Accordingly, GIS algorithms using the free remote sensing data were used to rank the probable mineralised zones before any future implementations of the high-cost drilling and/or detailed geophysical programmes. Geological and tectonic settings, and being a historical mineral resource were motivations to choose the Allaqi-Heiani Suture (AHS), Upper Egypt, as a study area. Remote sensing data were processed for tracing the probably mineralised alteration zones, determining fractures and dominating structural systems, and mapping different geological units. Various alteration minerals including hydroxyls–carbonates, ferrous and ferric iron oxides were detected over different rock units using band ratio (BR) and Crosta techniques. Different geological units were distinguished using false colour composite (FCC) images. Moreover, an intense fractured system, demonstrating the area, was revealed by tracing lineaments using informative, spatially enhanced remote-sensed images. Fractures within the altered rocks represent 35% of the total fracturing system in the AHS to indicate a structural system controlling mineralisation occurrences. The processing of magnetic data suggested a deep/buried nature of these remotely detected lineaments/structures. Reduced to pole (RTP) and tilt derivative (TDR) maps detected the buried magnetic sources, whereas zero contours of TDR, Euler deconvolution, analytic signal and source parameter imaging (SPI) techniques traced buried contacts/structures and estimated their depths. A GIS strategy depending on the intensity of the fracturing system and the presence of more than one type of alteration was applied to potential-rank the prospective mineralised occurrences over AHS. The correlation between ranked zones with the old/known mines showed encouraging evaluation.

Implementation of Petrographical and Aeromagnetic Data to Determine Depth and Structural Trend of Homrit Waggat Area, Central Eastern Desert, Egypt

In the current study, we conducted petrographic investigation combined with aeromagnetic data in order to classify variable granitic rocks, delineate structural trends and deduce depth of the basement rocks cropping out in Homrit Waggat area, Central Eastern Desert, Egypt. Field and petrographic investigations revealed that the granitic Homrit Waggat rocks include two groups. The first group includes the older granitic rocks, comprising tonalites and granodiorites. In contrast, the second one includes younger granitic rocks, involving alkali-feldspar granites, syenogranites and albitized granites. Depth as well as subsurface structures can be identified using magnetic method. Two tectonic maps representing the deep-seated and the shallow-seated structural features were constructed to show the structural history of the study area. The major tectonic trends indicate that the regional structures are controlled by deeper structures which have NW–SE, NNE–SSW—NE–SW and N–S directions. On the other hand, we find that the local structure trends are controlled by the local shallow structures that have NNE–SSW, NNW–SSE, ESE–WNW and N–S directions. Depth levels of the economic rare metal-bearing rocks range from 0 km to 1.2 km (Euler deconvolution technique) and from 0 km to 2.3 km (the analytical signal profiles) by using the aeromagnetic data, reflecting large resources of rare metal-bearing rocks.

Detection of sub-surface fractures based on filtering, modeling, and interpreting aeromagnetic data in the Deng Deng – Garga Sarali area, Eastern Cameroon

Abstract The aeromagnetic anomalies existing in the Deng Deng – Garga Sarali region in Eastern Cameroon were filtered for a structural study of the region’s subsoil. This study presents the results of lineaments and fractures extracted by aeromagnetic image processing methods and compared with scientific data to obtain potential terrain models in the study area. The methodological approach used is based on the filtering of aeromagnetic image by using the analytical signal, the Euler deconvolution, and 2D3/4 modeling, to establish the maps of the lineaments and faults of the study area and their characteristics, and also to propose three models from three previously chosen profiles. Analytical signal and Euler deconvolution techniques have been applied to aeromagnetic anomalies to highlight the relationship between the depth and the source of magnetic anomalies, two parameters whose importance in geoexploration and modeling of the body is essential. We identified the potential contacts by interpretation of the deep Euler anomalies, these are highlighted on the basis of a certain similarity between the maps of the total magnetic field, the map of the analytical signal, the map of the maxima of the gradient horizontal, and geological map. Euler’s map of solutions correlates well with the edges of certain superficial and deep causative bodies.

Basement depth re-valuation of anomalous magnetic bodies in the lower and middle Benue trough using Euler deconvolution and spectral inversion techniques

Spectral technique and Euler Deconvolution were applied to high-resolution aeromagnetic data of parts of Benue trough to estimate the depth of anomalous magnetic sources within the study area; Data enhancement techniques such as total magnetic intensity map, reduction to pole, regional-residual separation and upward continuation maps were employed to identify different magnetic anomalies, structural trends representing the tectonics of the location were observed trending NE-SW and N-S directions; The result of 3D Euler deconvolution for the structural index (SI) = 0, 1, 2, 3 gave depths to magnetic sources that range from -589;3 m to -2678;8 m, -459;0 m to -2691;9 m, -294;6 m to -2817;5 m, - 430;2 m to -2780;6 m respectively; The depth estimates from 2-D spectral revealed a two-layer model; The shallow magnetic depth ranges between 0;135 km to 0;200 km with a mean depth of 0;158 km and the depth to magnetic basement vary between 2;585 km to 4;878 km with a mean depth of 3;415 km; This result, therefore, indicates that the average basement depth of the study area obtained from the spectral analysis is 3;415km; This investigation, therefore provides appropriate sedimentary thickness for suitable hydrocarbon prospecting within the study area.

Basement depth re-valuation of anomalous magnetic bodies in the lower and middle Benue trough using Euler deconvolution and spectral inversion techniques

Basement depth re-valuation of anomalous magnetic bodies in the lower and middle Benue trough using Euler deconvolution and spectral inversion techniques

Gravity study of the Western Bahira Basin and the Gantour Phosphatic Plateau, central Morocco: Interpretation and hydrogeological implications

The Western Bahira Basin (WBB), located in Central Morocco, is known for its large reserves of phosphate, which are currently being extracted through open pit mines within the Gantour Phosphatic Plateau (GPP). This mining activity, as well as the increasing agricultural development that this region has been experiencing during the last few decades, has subjected the groundwater in this semi-arid region to intense exploitation through pumping. Consequently, thorough knowledge of the underground water resources is essential for sustained activity.This study uses gravity data to investigate the deep geologic structure of the western Bahira and Gantour plateau area. Its main purpose is to improve the knowledge of this structure that influences the groundwater dynamics.The methodology involves, in addition to the qualitative and quantitative interpretation of the gravity data, the use of various filtering and analysis techniques to highlight the major geological structures. In fact, a qualitative analysis of the residual gravity map shows that the observed anomalies can be explained in terms of the bedrock topography of the study area. Positive anomalies spatially correlate with the outcrops of this bedrock in the Hercynian massifs of Jebilet and Rehamna, as well as with the Douar Rhirat structural high. The negative anomalies, on the other hand, tend to reflect increased thicknesses of sedimentary sequences, such as in the southern part of the WBB. Moreover, the Brikyine granite in the north of the study area is noticeably associated with the highest amplitude negative anomaly.Analysis of the residual gravity data using the total horizontal gradient, upward continuation, and Euler deconvolution techniques provides a quantitative assessment of the geologic structure. These methods help delineate various structures oriented in two main directions: N45E and N105E. Among these structures, several major faults have been identified. They are rooted at a maximum depth in excess of 2800 m. These faults are responsible for the general structure of the study area and the morphology of the basement.Furthermore, the 2D forward modeling, performed across the main negative gravity anomalies of the WBB, helps characterize the Paleozoic bedrock topography and provides more constraints on its variation. The resultant gravity models clearly show an asymmetric structure for the western Bahira trough. This depression is filled by sedimentary formations whose thickness at the depot-center can locally reach 1200 m. Additional analysis of piezometric data shows that the groundwater flows are controlled by the gravity structures highlighted in this study.

DELINEATION OF AIRBORNE MAGNETIC AND RADIOMETRIC STRUCTURES ASSOCIATED WITH GOLD MINERALIZATION OF MINNA AND ITS ENVIRONS, NORTHCENTRAL NIGERIA

This study utilized the interpretation of the airborne magnetic and radiometric data to delineate the potential structures that are associated with gold mineralization of the Minna and its environs, Northcentral Nigeria. The total field anomaly data was reduced to pole and upward continued in a bid to well positioned and enhanced the shallow (high pass) magnetic structures. The high pass structural lineaments were extracted and the resulting prominent E-W and NE-SW tectonic trends were revealed which are perhaps related to Eburnean (D1) and Pan-African (D2) deformation events respectively. Subsequently, numerous regions with relatively high degree of faulting and shearing effects were unraveled from the line density analysis of the high pass lineaments. The 3-D Euler deconvolution technique provides a synonymous trend pattern with the HP lineaments as well as estimate the depth extents to the potential structures with values varying between 82.7 and 211.9 m. It was found that the mineralized structures associated with gold over the study area interact with the hydrothermal fluids alongside/adjacent to the structurally deformed (relatively high degree of faulting and shearing effects) regions. The observed regions with coincident, of the hydrothermally altered and structurally deformed are therefore marked as the resourceful, structures for gold mineralization. Hence, the derived evidence from this study has updated the information on the structures that are associated with gold mineralization and also acts a mitigation major against the indiscriminate excavations of the studied region.

Analysis of VLF-EM Data for Potential Cassiterite Mineralization Delineation Zone in Rafin-Bareda Area North-Western Nigeria

VLF-EM geophysical technique was employed to delineate potential cassiterite mineralization at Rafin Bareda, Dutsen-Wai, Kubau Local Government area of Kaduna state, North Western, Nigeria. A total area of 3.025 km2 was covered along eleven (11) traverses separated by 25 m with a measurement interval of 10m taken in the East-West direction. The response of the in-phase component revealed various anomalous zones while Fraser-filtered plots of the in-phase peaked over the anomalous zones and the Karous-Hjelt filtered response of the in-phase correlates quite well with the results of the Fraser filtered data. In order to achieve the aim of the investigation, and since the VLF data was collected in the magnetic mode, enhancement procedures such as reduced to equator and analytical signal techniques were applied to the Fraser Filtered response of the In-phase component and correspondingly, Center for Exploration Targeting (CET), Source Parameter Imaging and Euler Deconvolution algorithms of the Oasis Montaj were successively employed to delineate potential mineralization zones and best locations for drilling productive cassiterite in the study area. Enhanced maps show linear features trending in the NE-SW and NW-SE directions with minor traces in the N-S direction. Most of the delineated zones of high analytical signal signature were either intercepted or flanked by the extracted lineament which is indicative of positive correlation between the extracted lineament and the high amplitude response of the analytical signal and also, validated the occurrence and positioning of the cassiterite mineral deposits is greatly controlled by the lineament system across the study area and the development of conductive zones of high apparent current with positive values reflects inferred subsurface structural fractures and/or mineralized zones. Depths evaluation analysis from the Euler Deconvolution (ED) technique using structural index of 1, ranged from 5 m to 15 m while depths varying from 4.9 m to 13.7 m were obtained from the Source parameter imaging technique.

Interpretation of Aeromagnetic Data of Part of Gwagwalada Abuja Nigeria for Potential Mineral Targets

This study analyzes aeromagnetic data over a section of Gwagwalada in Abuja. The data were obtained from the Nigerian Geological Survey Agency acquired at 100 m terrain clearance. The study area spans longitudes 7.0875 E to 7.1458 E and latitude 8.9625 N to 9.0 N (about 27 km2). The dataset was reduced to the equator (RTE) and downward continued by 50 m. Analytic signal filter was applied on TMI-RTE grid to detect the edges of the magnetic bodies present. The structure was observed to trend NE-SW. The CET lineament map reveals intersections such as junctions and corners on the map. This revealed structure liable for potential mineralization zone. Euler deconvolution technique applied over the transformed dataset ascertain the location and depth of the structure,having a maximum depth of about 421 m and a minimum of about 59 m.Variation in magnetic depth and susceptibility contrast is specified by the gridded SPI depth map.

Integrated geophysics analysis of crustal structure in the NE Pirapora aulacogen, Brazil

The São Francisco Craton and its adjacent units show several main structural features. One of the most intriguing structures is the Pirapora Aulacogen, the largest Proterozoic rift structure preserved in the São Francisco Basin that records the Gondwana breakup event. This work used gravity and magnetic data to estimate geological structures within Pirapora Aulacogen, located on the eastern part of São Francisco Craton. The integrated geophysical and geological data analysis allowed us to increase geophysical information on this area by the magnetic and gravity signatures. Spectral analysis of the gravity and magnetic data revealed the depth of the sources of structures hosted basement. From potential field data, the Analytic Signal Amplitude (ASA), the Vertical Derivative (VDR), Tilt Derivative (TDR), and the Total Horizontal Derivative (THDR) products, it was possible to identify important signatures, as well as to delimit main structures. The Euler deconvolution technique provided estimates of the locations and depths of magnetic and gravity sources. It revealed important structures in the sedimentary cover and also structures responsible for the basement uplift. Modeling these data was performed in a strategic section of the study area to create a geological-geophysical model representing the subsurface geological features. The forward modeling and the inversion of the gravity and magnetic data generated from conventional susceptibility and the Magnetization Vector Inversion (MVI) were correlated to create a geophysical-geological model that presents the main geological features. The difference between conventional susceptibility and MVI results confirmed a strong magnetization remanence in the area. The largest amplitudes of the local gravitational field, also observed in the gravity inversion, are interpreted due to the basement uplift in the mountain regions: Serra do Cabral and Água Fria. The main structures revealed in the section are associated with grabens and horsts, describes as reactivated structures that controlled São Francisco Basin sedimentation.

The Use of Euler Deconvolution Technique in the Estimation of Depth to Magnetic Source Bodies around the Schist Belt Parts of Kano State, Nigeria

Abstract: Depth estimation of magnetic source bodies in parts of the Schist Belt of Kano, using Euler Deconvolution is presented in this paper. Detail ground magnetic survey was carried out using SCINTREX proton precession magnetometer to produce the Total Magnetic Intensity (TMI) map and consequently the residual map. The TMI ranges from 34,261 nT to 34,365 nT, while the residual field ranges from -160 nT to 115 nT. The depth estimate for contacts ranges from 6.5 m to 39.8 m, while that of dyke ranges from 8.9 m to 51.3 m. The depth estimation presented in this work is compared with the results of aeromagnetic study carried out in the same area and found to agree fairly well. Further, this also ensures the validity of aeromagnetic investigation in such applications. Keywords: Contacts, Dykes, Euler Deconvolution, Schist Belt. PACS: 91.25.F and 91.25.Rt.