The crustal nature of the northern Mozambique Ridge,Southwest Indian Ocean |
| |
Authors: | Nelta David Matsinhe Yong Tang Chun-Feng Li Jiabiao Li Estev?o Stefane Mahanjane He Li Yinxia Fang |
| |
Institution: | Institute of Marine Geology and Resources,Zhejiang University,Zhoushan 316021,China;Key Laboratory of Submarine Geosciences,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;Institute of Marine Geology and Resources,Zhejiang University,Zhoushan 316021,China;Key Laboratory of Submarine Geosciences,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;School of Oceanography,Shanghai Jiao Tong University,Shanghai 200240,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519080,China;College of Marine Science and Technology,China University of Geosciences,Wuhan 430074,China;College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Institute of Marine Geology and Resources,Zhejiang University,Zhoushan 316021,China;Laboratory for Marine Mineral Resources,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;Key Laboratory of Submarine Geosciences,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;Institute National Petroleum(INP),Maputo 4724,Mozambique |
| |
Abstract: | The Mozambique Ridge (MOZR) is one of the basement high structures located in the Southwest Indian Ocean, parallel to the Southeast African continental margin. It was formed as a result of the tectono-magmatic evolution of the Gondwana breakup. The origin of the MOZR has been highly debated, with models suggesting either continental or oceanic origin. With new free-air gravity anomaly and multichannel seismic (MCS) reflection data, we present results of 2D density modeling along two seismic profiles acquired by R/V Xiangyanghong 10 at the northern Mozambique Ridge (N-MOZR) between 26°S and 28°S. We observed high free-air gravity anomaly and strong positive magnetic anomaly related to the emplaced seaward dipping reflectors (SDR) and high density lower crustal body (HDLCB), and high Bouguer gravity anomaly associated with the thinning of the continental crust underneath the N-MOZR over a distance of ~82 km. This suggests a thinned and intruded continental crust bound by the Mozambique Fracture Zone (MFZ) that is characterized by gravity low and negative magnetic anomaly. This fracture zone marks the continent-ocean boundary (COB) while the N-MOZR is the transform margin high, i.e., marks the continent-ocean transition (COT) of the Southern Mozambique margin, following the definition of transform margins. We suggest that the N-MOZR was formed by continental extension and subsequent breakup of the MFZ, accompanied by massive volcanism during the southward movement of the Antarctica block. The presence of SDR, HDLCB, and relatively thick oceanic crust indicates the volcanic nature of this transform margin. |
| |
Keywords: | crustal nature northern Mozambique Ridge seaward dipping reflection gravity modeling continent-ocean transition continent-ocean boundary |
本文献已被 万方数据 等数据库收录! |
| 点击此处可从《海洋学报(英文版)》浏览原始摘要信息 |
| 点击此处可从《海洋学报(英文版)》下载免费的PDF全文 |
|