High-Precision Structural Map of Southeast Cameroon Using Phase Filters on Potential Gravimetric Data  

作　　者：Nzeuga Alain Rodrigue Bisse Salomon Bertrant Amaya Adama Kenfack Fokem Alpha Baster Ngah Christian Gislain Leonel Ndjounguep Juscar Nanfa Tefak Fatoumata Maelle Ngoumou Paul Claude Assembe Stéphane Patrick Pokam Kengni Serge Hugues Nzeuga Alain Rodrigue;Bisse Salomon Bertrant;Amaya Adama;Kenfack Fokem Alpha Baster;Ngah Christian Gislain Leonel;Ndjounguep Juscar;Nanfa Tefak Fatoumata Maelle;Ngoumou Paul Claude;Assembe Stéphane Patrick;Pokam Kengni Serge Hugues(Department of Petroleum Gas and Exploration, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon;Department of Geological Mapping and Geomatic, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon;Department of Mining Geology, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon;Postgraduate School of Science Technology and Geosciences, University of Yaounde I, Yaounde, Cameroon;Institute of Mining and Geological Research, Ministry of Scientific Research, Yaounde, Cameroon;Department of Geophysics, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon;Department of Physics, Faculty of Science, University of Bamenda, Bambili, Cameroon)

机构地区：[1]Department of Petroleum Gas and Exploration, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon [2]Department of Geological Mapping and Geomatic, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon [3]Department of Mining Geology, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon [4]Postgraduate School of Science Technology and Geosciences, University of Yaounde I, Yaounde, Cameroon [5]Institute of Mining and Geological Research, Ministry of Scientific Research, Yaounde, Cameroon [6]Department of Geophysics, School of Geology and Mining Engineering, University of Ngaoundere, Meiganga, Cameroon [7]Department of Physics, Faculty of Science, University of Bamenda, Bambili, Cameroon

出　　处：《Open Journal of Earthquake Research》2022年第4期89-107,共19页地震研究（英文）

摘　　要：The south-east of Cameroon encompasses a wide variety of geological structures among which we can cite the Congo Craton (CC), the Sanaga Fault (SF), the Yaoundé Domain, the Panafrican belt, the Protozoic series and the Dja complex. The presence of all these structures justifies the great tectonic activity to which this area was subject from the rupture of Pangea to the creation of the different plates that exist today. In this work, we will bring out a high-resolution structural map of the study area by applying the qualitative analysis of the phase filters on 200,900 points of gravimetric data obtained from the combination of the XGM2016 and ETOPO1 models. Then, with these same data, we will bring out another structural map with the maxima method called Multi-Scale Horizontal Derivative of Vertical Derivative (MSHDVD) which will be compared to the first in order to show the limits of the MSHDVD method. To do this, we will first use the extension method to highlight the map of residual anomalies, then a combination of derivative, gradient and phase filters to highlight the geological structures responsible for fracturing in this area. Phase filters have the advantage that they make it possible to highlight all the geological edges responsible for the fracturing without taking into account the depth, while the MSHDVD method highlights the existing geological contacts (edges) at depths well defined by the examiner. The structural map obtained with the MSHDVD method shows that the major structural direction in this zone is W-E while that obtained from the interpretation of the phase filters is more precise and shows that the major structural direction in this area would be N-S and this result would be in perfect agreement with the tectonics of East Cameroon.The south-east of Cameroon encompasses a wide variety of geological structures among which we can cite the Congo Craton (CC), the Sanaga Fault (SF), the Yaoundé Domain, the Panafrican belt, the Protozoic series and the Dja complex. The presence of all these structures justifies the great tectonic activity to which this area was subject from the rupture of Pangea to the creation of the different plates that exist today. In this work, we will bring out a high-resolution structural map of the study area by applying the qualitative analysis of the phase filters on 200,900 points of gravimetric data obtained from the combination of the XGM2016 and ETOPO1 models. Then, with these same data, we will bring out another structural map with the maxima method called Multi-Scale Horizontal Derivative of Vertical Derivative (MSHDVD) which will be compared to the first in order to show the limits of the MSHDVD method. To do this, we will first use the extension method to highlight the map of residual anomalies, then a combination of derivative, gradient and phase filters to highlight the geological structures responsible for fracturing in this area. Phase filters have the advantage that they make it possible to highlight all the geological edges responsible for the fracturing without taking into account the depth, while the MSHDVD method highlights the existing geological contacts (edges) at depths well defined by the examiner. The structural map obtained with the MSHDVD method shows that the major structural direction in this zone is W-E while that obtained from the interpretation of the phase filters is more precise and shows that the major structural direction in this area would be N-S and this result would be in perfect agreement with the tectonics of East Cameroon.

关 键 词：GRAVIMETRY Potential Field Data Edge Detection Structural Mapping Southeast Cameroon 

分 类 号：P31[天文地球—固体地球物理学]