Thermal Regime of the Lithosphere under the Taimyr Peninsula According to Geomagnetic Data

Abstract

This article presents the results of a study of the thermal regime of the lithosphere under the TaimyrPeninsula and adjacent territories (70°–80° N, 80°–115° E) based on geomagnetic data. Spectral analysis ofthe lithospheric geomagnetic field given by the EMAG2v3 model was performed using the centroid method.The calculations we performed showed that the minimum depths of the top boundary of lithospheric magneticsources (2.5 km) are typical for the entire Taimyr fold belt and the considered part of the Siberian Platform,and the maximum (6 km) for the North Kara Basin. The position of the top boundary of the magneticallyactive layer of the lithosphere above the bottom of the sedimentary layer under the Yenisei-Khatangaand Khatanga-Lena basins can be associated with the widespread intrusion of basalt traps into the sedimentarylayer. The minimum depths of the bottom boundary of lithospheric magnetic sources (36 km) are confinedto the Eurasian Basin and neighboring territories of the Laptev Sea shelf and the islands of the SevernayaZemlya archipelago, which indicates the greatest heating of the lithosphere under them within theregion under consideration. The depth of the bottom boundary reaches maximum values (≥48 km) under theYenisei-Khatanga and North Kara basins and the Siberian Platform, indicating the existence of the cold and,accordingly, thick lithosphere here, which is confirmed by other independent geophysical data