A NEW MODEL OF THE NINETY EAST RIDGE FORMATION, INDIAN OCEAN

1 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

2 Géosciences Environnement Toulouse, Toulouse, France

3 Lomonosov Moscow State University, Geological Department, Moscow, Russia

* e-mail: vkillar@mail.ru

Abstract. A comprehensive analysis of geological, geophysical, and geochemical data allow us to obtain the most complete picture of the geological structure of the central part of the Ninety East Ridge (NER), the Osborne Plateau, and the adjacent part of the Central Basin. It has been established that this region is a complex tectonic structure. The revealed structural features of the main sub-meridional faults of Indrani, Indira and Lanka showed that they are not transform faults. Based on the generalization of the all available data on the northern and southern parts of the NER, supplemented by the studies of the central part of the NER, it was found that the NER was constructed on a continental crust of the ancient continent, likely Lemuria. A new model of the NER formation is proposed, according to which it is a relict fragment of this continent, preserved in the form of a block or an escarp, an extended horst structure. To write this article, primary materials were obtained from various sources of domestic scientific and industrial organizations and studies performed during expeditions in the Central Basin during 1980-1990s, as well as materials from other sources, including foreign sources.

Keywords: block morphostructure, tectonomagmatic relief, taphrogenic mode, transitional crust.

About the authors

ILLARIONOV Vladimir K. – Cand. Sci. (Geol. and Min.), senior researcher, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. Tel.: +7 (499) 254-68-95. E-mail: vkillar@mail.ru

BOYKO Anatoly N. – Cand. Sci. (Tech.), leading researcher, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Russia, 123242, Moscow, Bolshaya Gruzinskaya st., 10-1. Tel.: +7 (499) 254-68-95. E-mail: boyko@ifz.ru

BORISOVA Anastassia Yu. – Dr. Sci. (Geol. and Min.), research associate, Géosciences Environnement Toulouse. France, 31400, Toulouse, Avenue E. Belin, 14; Lomonosov Moscow State University, Geological Department. Russia, 119991, Moscow, Leninskie Gori, 1. E-mail: anastassia.borisova@get.omp.eu

Cite this article as: Illarionov V.K., Boyko A.N., Borisova A.Yu. A new model of the ninety east ridge formation, Indian ocean, Geofizicheskie Protsessy i Biosfera (Geophysical Processes and Biosphere), 2019, vol. 18, no. 4, pp. 225–240 (in Russian). https://doi.org/10.21455/gpb2019.4-19

English version: Izvestiya, Atmospheric and Oceanic Physics, 2019, vol. 55, iss. 11. ISSN: 0001-4338 (Print), 1555-628X (Online). https://link.springer.com/journal/volumesAndIssues/11485