Digital models of the deep structure of the Earth’s crust in the Eurasian Basin of the Arctic Ocean

Abstract

Based on the method of gravity modeling, taking into account the accumulated geophysical data on the Eurasian Basin of the Arctic Ocean, the authors have developed digital models of the deep structure of the Earth’s crust. The digital models of the basement relief and sedimentary cover thickness in the Eurasia Basin are calculated on the basis of reinterpretation of depth multi-channel seismic cross-sections and 2D gravity modeling. The digital models of the Mohorovichich surface relief and the earth’s crust thickness were calculated using the improved 3D gravity modeling method. It is shown that the reason for the deepening of the basement in the Nansen Basin by 1‒1.5 km in comparison with the Amundsen Basin is a larger volume of accumulated sedimentary cover in the Nansen Basin, with a similar thickness of the crust ~4.8 km in both basins. The characteristics of the oceanic crust studied on the basis of the obtained digital models reveal a complex, three-dimensional variability characteristic of ultra-slow spreading ridges. In the region of the Gakkel Ridge, which was formed at full spreading rates of less than 12 mm/year, the maximum spread of crust thickness is observed, as well as the predominance of the role of the tectonic factor over the magmatic one during the accretion of oceanic crust. Latter fact is expressed in the formation of extended subsea ridges parallel to the amagmatic segments of the ridge.