Investigating the Depth and the Geometry of the Quarzitic Panafrican Basement Using Near-Surface 3D Seismic Refraction Tomography: Case Study of the Locality of Bakel (Senegal)  

作　　者：Mapathe Ndiaye Oustasse Abdoulaye Sall Alassane Thiam Déthié Sarr Moustapha Badji Issa Ndoye Mapathe Ndiaye;Oustasse Abdoulaye Sall;Alassane Thiam;Déthié Sarr;Moustapha Badji;Issa Ndoye(Laboratory of Mechanics and Modeling, Faculty of Engineering, University of Thies, Thies, Senegal)

机构地区：[1]Laboratory of Mechanics and Modeling, Faculty of Engineering, University of Thies, Thies, Senegal

出　　处：《International Journal of Geosciences》2020年第6期345-359,共15页地球科学国际期刊（英文）

摘　　要：<div style="text-align:justify;"> <span style="font-family:Verdana;">Seismic refraction investigations have been carried out in Bakel, Eastern Senegal. The purpose was to map geometrical relationship between the existing rock types and the Panafrican quarzitic basement, which is valuable information for the project of the Bakel fluviatile port construction. Four seismic refraction profiles were acquired. The obtained data have been processed by inversion. The obtained four seismic P-wave velocity profiles have been integrated to obtain a 3D model. By comparing the outcropping geological formations with the observed seismic data at the surface, it was possible to identify the lithology corresponding to each measured range of seismic velocity for the alluvium, the weathered bed rock, and the fresh rock. The results showed that the depth of the fresh rock of the basement varies from 0 to 18 meters above the sea level, with a deepening toward the Senegal River and toward the Northern part of the studied area. The presence of alluviums and their thickness are linked to the existence of bays and gulfs. The results of this study give valuable information for the river bed dredging cost assessment prior to the port construction phase.</span> </div><div style="text-align:justify;"> <span style="font-family:Verdana;">Seismic refraction investigations have been carried out in Bakel, Eastern Senegal. The purpose was to map geometrical relationship between the existing rock types and the Panafrican quarzitic basement, which is valuable information for the project of the Bakel fluviatile port construction. Four seismic refraction profiles were acquired. The obtained data have been processed by inversion. The obtained four seismic P-wave velocity profiles have been integrated to obtain a 3D model. By comparing the outcropping geological formations with the observed seismic data at the surface, it was possible to identify the lithology corresponding to each measured range of seismic velocity for the alluvium, the weathered bed rock, and the fresh rock. The results showed that the depth of the fresh rock of the basement varies from 0 to 18 meters above the sea level, with a deepening toward the Senegal River and toward the Northern part of the studied area. The presence of alluviums and their thickness are linked to the existence of bays and gulfs. The results of this study give valuable information for the river bed dredging cost assessment prior to the port construction phase.</span> </div>

关 键 词：Panafrican ALLUVIUM QUARTZITE Seismic Refraction Tomography 3D Model Bakel Senegal 

分 类 号：P31[天文地球—固体地球物理学]