New Advances in the Study on Ages of Metamorphic Strata in the Qinling Orogenic Belt
秦岭造山带主要疑难地层时代研究的新进展

Many micro-fossils and chronologic data were obtained in the metamorphic strata of the Qinling Orogenic Belt through palaeontologic, chronologic and structural studies in recent geological survey. Ordovician fossils were found in the Kuanping and Taowan Groups in North Qinling; Carboniferous fossils were found in the Yaolinghe and Yunxi Groups (formerly assigned to Late Proterizoic) and their isotopic ages were determined; Devonian fossils were also found in the Sanhuashi and Bikou Groups (formerly assigned to Late Proterozoic) and Donghe Group (formerly assigned to Early Paleozoic) in South Qinling. An accretionary complex belt was determined, and it is composed of Silurian strata and its Lower Paleozoic concomitant strata north of the Mianxian-Lueyang-Yangxian-Shiquan-Ankang fault in South Qinling. The final formation age of this belt was deduced to be Late Permian or Early Triassic by new findings of fossils and dating of debris zircon in matrices made up of turbidites.