Provenance and source rocks of Riphean sandstones in the Uchur-Maya region (east Siberia): Implications of geochemical data and Sm-Nd isotopic systematics

As is shown based on geochemical data and Sm-Nd isotopic systematics, accumulation of sandy deposits in the Riphean protoplatform cover of the Southeast Siberian platform was controlled by influx of primary and recycled sedimentary material derived from magmatic and metamorphic complexes of the eastern Aldan shield in the course of denudation of the Early Proterozoic accretionary orogen formed prior to 1.9 Ga. First indications of endogenic material influx into sedimentary basins are established in the Totta Formation of the Middle Riphean. They mean contribution to sedimentation of material weathered and eroded from external recycled orogens and synsedimentary volcanics that marked commencement of rifting in the platform marginal zone. Provenances of this material were situated most likely to the east and southeast off the Yudoma-Maya trough.