Tectonic structure and conditions for the formation of the marginal plateau and Socotra Island (physical modeling). Part 1. Structure of the Socotra Island

Abstract

The structure of the eastern part of the Gulf of Aden is peculiar for the presence of a submerged plateau and the island of Socotra, which were formed at the initial stage of its formation. With the beginning of continental rifting in the Oligocene-Miocene, more ancient riftogenic structures of the Mesozoic age were reactivated. This was most revealed in the relief in the Guardafuy graben, which cuts off the base of the Socotra plateau from the shelf of the modern eastern tip of the Horn of Africa. During tension, there were significant rotational deformations of the entire plateau. Socotra Island is divided into two parts by the large Hadibo transfer zone. The morphostructure of the elevated eastern part is determined by the asymmetric arch-like Hajhir Mountains. The western part is deformed much more strongly than the eastern part and is strongly broken by steeply falling faults. The continental margins of Socotra Island in the eastern province of the Gulf of Aden are amagmatic, asymmetrical and fractured by a series of faults and detachments. The difference in their structure is explained by the peculiarity of the transition from continental rifting to spreading, associated with the hyper-extension of the continental crust. In order to understand the conditions of riftogenesis, under which the formation of the continental block of the submerged marginal plateau and the island of Socotra is possible, the authors carried out a physical simulation, the results of which are presented in Article 2.