非洲西海岸里奥-德雷盆地泥底辟平面地质结构特征研究OA北大核心CSTPCD

The Rio del Rey basin,located in the eastern margin of the Niger Delta Basin in West Africa,develops large-scale mud diapirs.There are some disputes about the activity time and mechanism of the diapirs.Based on the detailed interpretation and mapping of the 3D seismic profile of the Rio del Rey basin,the distribution characteristics of the mud diapir on the top surface of the Miocene Nguti structural layer are redefined.The results show that:(1)mud diapir on the top of the Nguti structural layer can be divided into the northern buried area,the central pierced area,and the southern pierced area;(2)the mud diapir in the northern buried area was formed before the deposition of the Nguti structural layer,and was a passive mud diapir controlled by early sedimentation.The mud diapir in the central pierced area was formed before the deposition of the Pliocene S0 structural layer,and was an active mud diapir developed under the action of gravity sliding structures.The mud diapir in the southern pierced area was formed after the deposition of the Nguti structural layer,and was a thrust mud diapir controlled by thrust structures at the front edge of the gravity structure;(3)the mud diapir as a whole is a tongue shaped body protruding southward,divided into two segments:the west segment along a NNW-NW direction,and the east segment along a NNE-NE direction.