The Gulf of Guinea constitutes an area of great petroleum potential yet with very limited geophysical research information. Consequently in this study, a Bouguer anomaly map has been computed from gravity data coverin...The Gulf of Guinea constitutes an area of great petroleum potential yet with very limited geophysical research information. Consequently in this study, a Bouguer anomaly map has been computed from gravity data covering regions stretching from the Cameroon coastal basins to Bioko island (formerly Fernando Po) which is part of Equatorial Guinea. The data were further processed for Source Edge Detection (SED), Euler 3D deconvolution, 3D surface oriented models and 3D voxel solutions. The results confirmed the presence of previously identified intrusive bodies around the Douala and Kribi/Campo sedimentary sub-basins and went ahead to suggest a probable continuity between these two. A possible extension of this body offshore the Gulf of Guinea right up to Bioko island with very striking similarities was also highlighted and it shows characteristic variations in the depth to the surface of the body at different locations.展开更多
The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the r...The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the research object,a new method was used to obtain the quantitative relationship between intrusion morphology and skarn mineralization.The first step of the method was to extract morphological characteristic parameters based on mathematical morphology and Euclidean distance transformation;then the quantitative relationship between the parameters and orebodies was analyzed;finally correlational analyses between the parameters and mineralization indices were conducted.The results show that morphological characteristic parameters can effectively indicate the location of concealed ore bodies in skarn deposit,with the following parts as advantageous positions of skarn mineralization:(1)the parts away from the1st trend surface in the range from?25to50m;(2)the convex parts about200m away from the2nd trend surface,around which the tangent plane of the intrusive body is approximately consistent with the trend surface;(3)the contact zones with angle between intrusive body original contact surface and trend contact surface ranging from35°to70°;(4)the parts with angle between intrusive body original contact surface and regional extruding far crustal stress ranging from50°to60°.These knowledge can be applied to more skarn deposits for future mineral exploration.展开更多
The succession of tectonic phenomena in the South-West Cameroon area suggests that structures from the upper mantle infiltrated and took advantage of the cracks and fractures left by these phenomena to get closer to t...The succession of tectonic phenomena in the South-West Cameroon area suggests that structures from the upper mantle infiltrated and took advantage of the cracks and fractures left by these phenomena to get closer to the earth’s surface. However, the intrusive structures closest to the surface remain poorly known. The objective of this work is to improve the knowledge related to the interpretation of gravity data in order to characterise the near-surface intrusive bodies in the South-West Cameroon area, and then analyse their mining and geothermal implications. To achieve this objective, the indirect, inverse and normalized standard deviation (NSTD) methods were used. The NSTD method was used to detect the contours of the intrusive bodies. The indirect method (spectral analysis) was used to determine the depths of the interfaces of three intrusive bodies, one located on the Bipindi-Ebolowa I axis (G5), the other on the Eseka-Pouma axis (G8) and the last on the Bokito-Monatele axis (G11). The results obtained show roofs located between 0 and 0.61 km, between 0 and 0.37 km and between 0 and 0.73 km for the G5, G8 and G11 bodies, respectively. Finally, the application of the 2D inversion method allowed us to estimate the density contrasts of the intrusive bodies (G5, G8 and G11). The superposition of the intrusive bodies detected by the NSTD with the geological and mineral resources map, as well as an analysis of the results obtained, gave indications of interesting zones for mining prospecting and for the search for geothermal reservoirs.展开更多
文摘The Gulf of Guinea constitutes an area of great petroleum potential yet with very limited geophysical research information. Consequently in this study, a Bouguer anomaly map has been computed from gravity data covering regions stretching from the Cameroon coastal basins to Bioko island (formerly Fernando Po) which is part of Equatorial Guinea. The data were further processed for Source Edge Detection (SED), Euler 3D deconvolution, 3D surface oriented models and 3D voxel solutions. The results confirmed the presence of previously identified intrusive bodies around the Douala and Kribi/Campo sedimentary sub-basins and went ahead to suggest a probable continuity between these two. A possible extension of this body offshore the Gulf of Guinea right up to Bioko island with very striking similarities was also highlighted and it shows characteristic variations in the depth to the surface of the body at different locations.
基金Projects(41472301,41472302) supported by the National Natural Science Foundation of China
文摘The shapes of intrusive body and contact zone might influence the formation and distribution of orebodies in skarn deposit.By taking Xinwuli intrusive body in Fenghuangshan copper deposit,Tongling,Anhui,China,as the research object,a new method was used to obtain the quantitative relationship between intrusion morphology and skarn mineralization.The first step of the method was to extract morphological characteristic parameters based on mathematical morphology and Euclidean distance transformation;then the quantitative relationship between the parameters and orebodies was analyzed;finally correlational analyses between the parameters and mineralization indices were conducted.The results show that morphological characteristic parameters can effectively indicate the location of concealed ore bodies in skarn deposit,with the following parts as advantageous positions of skarn mineralization:(1)the parts away from the1st trend surface in the range from?25to50m;(2)the convex parts about200m away from the2nd trend surface,around which the tangent plane of the intrusive body is approximately consistent with the trend surface;(3)the contact zones with angle between intrusive body original contact surface and trend contact surface ranging from35°to70°;(4)the parts with angle between intrusive body original contact surface and regional extruding far crustal stress ranging from50°to60°.These knowledge can be applied to more skarn deposits for future mineral exploration.
文摘The succession of tectonic phenomena in the South-West Cameroon area suggests that structures from the upper mantle infiltrated and took advantage of the cracks and fractures left by these phenomena to get closer to the earth’s surface. However, the intrusive structures closest to the surface remain poorly known. The objective of this work is to improve the knowledge related to the interpretation of gravity data in order to characterise the near-surface intrusive bodies in the South-West Cameroon area, and then analyse their mining and geothermal implications. To achieve this objective, the indirect, inverse and normalized standard deviation (NSTD) methods were used. The NSTD method was used to detect the contours of the intrusive bodies. The indirect method (spectral analysis) was used to determine the depths of the interfaces of three intrusive bodies, one located on the Bipindi-Ebolowa I axis (G5), the other on the Eseka-Pouma axis (G8) and the last on the Bokito-Monatele axis (G11). The results obtained show roofs located between 0 and 0.61 km, between 0 and 0.37 km and between 0 and 0.73 km for the G5, G8 and G11 bodies, respectively. Finally, the application of the 2D inversion method allowed us to estimate the density contrasts of the intrusive bodies (G5, G8 and G11). The superposition of the intrusive bodies detected by the NSTD with the geological and mineral resources map, as well as an analysis of the results obtained, gave indications of interesting zones for mining prospecting and for the search for geothermal reservoirs.
基金sponsored by the Subordinate subject of the National Major Science and Technology Project“Development of Large Oil and Gas Fields and coalbed methane”(2017ZX05001-003)supported by the National Natural Science Foundation of China”Simulation of Dynamic Process for Shale Oil Sweet Deposition in Lucaogou Formation,Jimusar Sag”(42072119).
