Geophysical research: article

D.A. Ryzhova
M.V. Kosnyreva
E.P. Dubinin
A.A. Bulychev
Lomonosov Moscow State University, Moscow, Russia
Journal: Geophysical research
Tome: 22
Number: 3
Year: 2021
Pages: 53-69
UDK: 550.831, 551.241
DOI: 10.21455/gr2021.3-4
Full text
Keywords: potential fields, seismotomography, earth crust, tectonosphere, rises, the Indian Ocean
Аnnotation: The results of studies carried out in the southwestern part of the Indian Ocean are presented. The studied region is characterized by a complex structure and the history of tectonic development. A characteristic feature of bottom relief of this region is the presence of underwater rises composed of blocks of both oceanic and continental origin. The development of the region was accompanied by manifestations of intense magmatic and tectonic activity, which led to the formation of a number of large underwater ridges and rises. An important place among them is occupied by the Mozambique and Madagascar ridges, the tectonic structure of which is still the subject of discussion. Based on the results of the analysis of potential fields, as well as seismic tomography information and data from other geological and geophysical studies, the authors identified differences in the structure and evolution of these ridges. The observed anomalous structure of the Earth's crust under them can be explained either by thickening of the oceanic crust from below due to magmatism (underplating process), as it is observed for the Madagascar Ridge, or by stretching and thinning of the continental crust, which occurs in the northern part of the Mozambique Ridge. Two-dimensional structural-density modeling was performed using four profiles that intersect the main structures of the lithosphere of the studied region. It is established that the Earth's crust of the Mozambique ridge is less dense than the crust the Madagascar ridge.
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