Гипербазиты как фактор геодинамики по результатам исследований на Таймырском геофизическом полигоне

Abstract

Seismic data indicate the widespread inversion origin of the largest geological structures of the Taimyr Peninsula and record repeated changes of the direction of tectonic movements. The inversion the Yenisei-Khatanga trough led to the formation of a system of megaarchs over the ancient depocenter containing massive hyperbasite intrusions at the Moho level, which are marked by the gravity maximum. These intrusive processes are an important factor that can initiate inversion and contribute significantly to its development under permanent compressional tectonic regime in the region.According to the geophysical data, the development of troughs in the north of Central and Western Siberia is associated with the formation of eclogites under the depocenters, at the Moho level. Consistent with the electrical resistivity anomalies, eclogites are plastic and overlap mantle hyperbasites of lower density that leads to gravitational buoying up of ultramafic formations. This, along with metamorphic and metasomatic processes, acts as an impulse for the uplift in the axial parts of the troughs. Simultaneously, expansion and acceleration of sagging, due to the displacement of plastic eclogites and crystal-mantle mixture from the penetration zone towards the peripheral parts of the sedimentary basin, result in the uncompensated sediment accumulation and the formation of the Neocomian clinoform complex.