Tittle: Identifying late Neoproterozoic-early Paleozoic sediments in the South Qilian Belt, China: A peri-Gondwana connection in the northern Tibetan Plateau
Abstract: The provenance and maximum depositional age of Neoproterozoic to early Paleozoic sedimentary rocks from the Balonggonggaer Formation (BF) in the South Qilian belt (northern Tibetan Plateau) is estab- lished using LA-ICP-MS UePb age determinations on detrital zircons taken from fifteen metasedimentary samples. The BF comprises two tectonically juxtaposed metasedimentary sequences that were derived from different source regions. Unit A is characterized by turbiditic facies, thick greywackes, and has zircons ages older than 0.7 Ga and is dominated by 2.2e1.8 Ga and 0.8e0.7 Ga populations that are compatible with a source region within the Quanji massif. Unit A might be deposited after the mid- Neoproterozoic and represent passive margin deposits that developed along the Quanji massif margin during Neoproterozoic continental break-up. Unit B is a highly deformed and metamorphosed sedi- mentary sequence, showing a distinct provenance dominated by age peaks at about 0.56e0.68 Ga, 1.2 e0.9 Ga and 1.60 Ga. These populations bear resemblance to those found in peri-Gondwana terranes. These results favor the placement of Unit B alongside northern peri-Gondwanan terranes. During the early Cambrian, the Qilian-Qaidam basement accreted to the northern margin of Gondwana along the Proto-Tethys. These two distinct sequences of the BF were juxtaposed along the northern margin of Gondwana during the Ordovician to middle Devonian.
Citation: Li M., Wang C., Li R., Meert J.G., Peng Y., Zhang J., (2019). Identifying late Neoproterozoic-early Paleozoic sediments in the South Qilian Belt, China: A peri-Gondwana connection in the northern Tibetan Plateau. Gondwana Research, 76, 173-184.
