Structure of the typical section of the lower carboniferous deposits of the east subzone of the Lemva zone (Polar Urals): part 1. Reconstruction

The article examines the composition and structure of the Lower Carboniferous part of the Yajyu Suite, common in the eastern subzone of the Lemva structural-formational zones of the Polar Urals. It is an indicator of the beginning of collision processes in the northern part of the Urals and reflects the geological history of this period. The scaly-thrust structure of the area, small isoclinal folds, numerous discontinuous disturbances, and redeposition of organic remains strongly obscured the succession of layers. The revealing of the lithological benchmark allowed to decipher the geological structure of one of the tectonic «scales» (plates) and to clarify the sequence of the Lower Carboniferous deposits in it. The section of the Yajyu Suite presented alternating packs of carbonate-terrigenous and carbonate rocks. The first ones were formed by underwater density flows; the second ones represented hemipelagic deposits. Their alternation in the section indicates the repeated change of hydrodynamically quiet sedimentation conditions with catastrophic. The composition of detrital material of carbonate-terrigenous and carbonate rocks of the Yajyu Suite on the Grubeyu River testifies to existence of shallow-water carbonate shelf in the east of the sedimentation basin (in modern coordinates) in the Early Carboniferous time.