The age, stratigraphy, and tectonic provenance of clastic deposits in the western Bikou terrane, southwestern Qinling Mountains, China

The Qinling Mountains of central China are the product of Late Paleozoic to Triassic collision between the North China Plate and the South China Plate. Located within the southwestern Qinling Mountains is the Bikou terrane, a low grade metamorphic assemblage of igneous and clastic sedimentary rocks located adjacent to the northern margin of the South China Plate. The age and tectonic setting of clastic deposits within the Bikou terrane have long been controversial, with age estimates ranging from Lower Proterozoic to Late Paleozoic, and tectonic provenance theories ranging from subduction arc to continental rift.; The southeastern portion of the Bikou terrane is composed of a metamorphosed volcanic arc with minor marine volcaniclastic sediments, known as the Bikou Group, previously dated by SHRIMP U-Pb zircon and conventional U-Pb as Late Proterozoic in age (approximately 845 to 760 Ma). Separated by a NE/SW striking fault, the northwestern Bikou terrane consists of a turbidite dominated sedimentary basin known as the Hengdan Group.; The Hengdan basin comprises a 10 to 15 km thick succession of coarsening upward, volcaniclastic sand-rich submarine fan deposits. (Abstract shortened by UMI.)...