Investigation of Shock Wave Dynamics in An Inhomogeneous Solar Atmosphere

The shock front (SF) propagation in the solar atmosphere with a power-law decrease of density is studied in the Kompaneets approximation. It is shown that the SF part moving from the Sun in the radial direction speeds up at the exponent n > 3 and slows down at n < 3. When passing from the lower corona with n = 6 to the solar wind with n = 2, the acceleration in the front part changes into deceleration. This result allows us to understand the kinematics of the SF obtained from the observational data on type II bursts at low frequencies. Besides, in the region of solar wind, new analytical solutions of the Kompaneets equation (KE) for SF have been obtained. One of them describes SF as an expanding sphere with the center moving from the Sun (plain case). Another solution has been obtained for the case of the inverse near-square law density depending on radius with the singularity at a given levelR.     

Tectonic map of the Vendian–Lower Paleozoic structural stage of the Lena–Tunguska petroleum province,Siberian Platform

A new version of the tectonic map for the Vendian–Lower Paleozoic structural stage of the Lena–Tunguska petroleum province is presented. The map is based on the electronic structure map at a scale of 1:1,000,000, which was the first to be compiled for the uppermost Vendian within the study area. However, no tectonic zonation was made for the deep-buried Meso-Cenozoic Yenisei–Khatanga and Vilyui depressions. The principles and methodology of mapping are given. The study presents spatial, morphological, and quantitative characteristics of the major and large structures.     

Setting of the Formation of Paleozoic Picrite Basalt Complexes in the West Siberian Plate Basement

⁴⁰Ar/³⁹Ar analysis showed a simultaneous (at about 490 Ma) formation of the Paleozoic picrite and basalt complexes of the West Siberian Plate basement. The petrochemistry, trace and REE geochemistry, and composition of clinopyroxene indicate the formation of the picrite of well no. 11 (Chkalov area) as a result of intraplate magmatism of the OIB type. Calculations based on the compositions of clinopyroxene allowed crystallization of minerals of porphyric picrite at 1215–1275°C and 4.5–8 kbar. In general, it has been found that the picrite basalt complexes considered were formed from enriched igneous plume systems under intraplate conditions near the active margin of the ancient ocean.