SOURCE AREAS AND GEODYNAMIC SETTINGS OF CENOZOIC DEPOSITS IN THE WEST SAKHALIN TERRANE BASED ON THE RESULTS OF STUDY OF HEAVY DETRITAL MINERALS

The paper describes the obtained data on content, the nature of distribution and composition of heavy detrital minerals from Cenozoic sandstones rocks in the West Sakhalin terrane. It shows that sandstones contain both the minerals of sialic (granitic–metamorphic) assemblage and the femic assemblage formed by products of volcanic rock destruction. Generalization and interpretation of the obtained data allow assuming that sedimentation occurred on the active continental margins in that basin relates to the large-scale strike-slip dislocations on transform faults. The source area, which supplied the detrital material into this basin, united the continental margins shaped by granite-metamorphic and sedimentary rocks and deeply dissected mature ensialic island arc, erosion of which recovered granitoid batholiths underlying the volcanic rocks. Besides, the source area included the fragments of accretionary prisms formed by ophiolites. The conducted U-Pb datings of detrital zircons allowed us to identify the main complexes of granitoids that were supplying clastic into the terrane’s sedimentary basins.