A NEW TYPE OF LARGE-SCALE MANIFESTATION OF WITHIN-PLATE INTRUSIVE TRAP MAGMATISM (WEST SIBERIAN CRATON)

Abstract

In terms of the manifestation of within-plate trap magmatism, the Siberian Craton (SC) is comparable only to the large-scale plateau basalt magmatism of oceans. At the present-day erosion level, trap magmatism of the SC with a huge volume of rocks of different facies (2.0 × 106 km3) includes nearly equal proportions of volcanic and intrusive formations. Trap intrusive bodies (up to 500 × 103 km3) are mainly confined to the western sector of the SC in the Tungus syneclise (near the Yenisei zone). The abundance of intrusive trap rocks in the study region was first noted by Sobolev. The subsequent geological survey, prospecting, exploration, geophysical works, and particularly the drilling of numerous oil wells revealed that intrusive trap structures are extremely diverse in dimension, morphology, and mineral composition.