Open AccessGeological structure of the Pre-jurassic basement of the Yugansk-Koltogorsk zone of the West Siberia
Author(s) -
К. С. Иванов,
С. В. Берзин,
N. V. Vakhrusheva,
Николай Павлович Костров,
O. E. Pogromskaya
Publication year - 2018
Publication title -
litosfera
Language(s) - English
Resource type - Journals
eISSN - 2500-302X
pISSN - 1681-9004
DOI - 10.24930/1681-9004-2018-18-6-839-858
Subject(s) - geology , basement , basalt , geochemistry , petrography , geochronology , rift , radiometric dating , biostratigraphy , microprobe , permian , paleontology , mineralogy , tectonics , archaeology , structural basin , history
Subject of the study. We have carried out an additional exploration on petrography, petrochemistry, geochemistry, geochronology and biostratigraphy of rock complexes of the Yugansk-Koltogorsk (central part of West Siberia). Materials and methods. The materials are core samples from wells that penetrated the Pre-Jurassic basement rock complexes The used methods are as follows: X-ray spectrum microanalysis (Cameca SX 100, JEOL-733 Superprobe); the silicate analysis of the rocks (СРМ-18 and EDX-100); mass-spectroscopy with inductively coupled plasma (ICP-MS) (ELAN-9000 and Element2); zircons were analysed with a high resolution ionic microprobe SHRIMP-II (U-Pb); Ar-Ar dating was carried out by Micromass 5400; biostratigraphy, petrochemestry. Results. A geological map of Yugan-Koltogor zone of the central part of West-Siberian plate in a scale 1:500 000 was created. The map is a set of informational geological, geophysical and other layers. It was established that age of granites is Early Permian, the basalts of the rift zone began to form 268.4 ± 7.5 Ma ago (Ar-Ar). Conclusions. Volcanism in the axial rift zones of the West-Siberian megabasin basement began earlier than it is supposed before our study and significantly earlier of that of trap basalts of Siberian platform.