Heterogeneities of the Earth's crust structure of the strait of Bransfield (West Antarctica) according to the data of geophysical studies
© Yu.V. Kozlenko, I.N. Korchagin, S.P. Levashov, V.D. Solovyov
Complex analysis of the data of geophysical studies (seismic, vertical electric sounding (VERS) and magnetic field) of the Earth's crust of the strait of Bransfield in West Antarctica has been conducted. According to the results of studies it has been found that position of anomalous magnetically active units within the Earth's crust, distribution of sills, identified by the method of VERS as well as the extent of the marginal parts of the block with anomalously high velocity, distinguished according to seismic data have similar regularities, namely - distribution to the sides and upward from the center of the trough of Bransfield at the average angle 5 . Similar results o btained with application of three different methods allow to state considerable magmatic dynamics of the trough of Bransfield which is being formed under conditions of structural transformations migrating along the strait of Bransfield from northeast to southwest. Seismic studies do not give unambiguous support of active spreading development and of presence of oceanic type crust in this part of the strait. It is quite probable that the process of diffusion spreading is prevailing in this region, not the accretion of the ridge of medial type in the rear of volcanic arc.