New data on chemical composition of Jurassic–Lower Cretaceous sedimentary rocks of the Bureya basin (Far East of Russia)

Resumo

The first data on the whole-rock chemical composition of Jurassic–Lower Cretaceous sedimentary rocks cropping out in the Soloni–Umal’ta river interfluve (Bureya sedimentary basin) are used for revealing the distribution of their rock-forming elements. It is shown that the clastic material originated mostly from acid igneous rocks, while their intermediate varieties, as well as quartz-rich sedimentary and metamorphic rocks, played a subordinate role. It is assumed that the bulk of the clastic material was transported from the west and southwest (Bureya massif) and a smaller share from the east. The most significant differences between the Lower–Middle Jurassic and Upper Jurassic–Lower Cretaceous rocks mark a break in sedimentation.