Record and Provenance Conversion Response of Detrital Zircon in Early Paleozoic of South Guizhou
The Dushan area in southern Guizhou Province is located on the southeastern margin of the Yan-gtze landmass,where relatively complete Lower Paleozoic strata are found.The study of detritastic zircon U-Pb age spectrum in this area can provide a new basis for further identification of the tectonic attributes of the pre-Late Paleozoic junction zone between the Yangtze Block and the Chinese Block and further study of the tectonic evolution of South China.In this paper,375 detrite zircons from 5 quartz sandstones of the Lower Devonian Dan-lin Formation in this area are analyzed.The cathodic luminescence of zircons is characterized by typical oscilla-ting bands,irregular zonings,Th/U ratio greater than 0.1,strong positive Ce anomaly and weak negative Eu a-nomaly.The 346 groups of harmonic ages were from multiple source regions,and the main age peaks of the 5 groups were 2 456 Ma,1 366 Ma,970 Ma,536 Ma and 402 Ma,with 970 Ma being the most prominent peak.It is believed that Paleozoic zircons originate from Caledonian granites in northern Guian-western Hunan,and Neoproterozoic zircons mainly originate from Neoproterozoic igneous rocks in Sibao Group and Danzhou Group in Jiangnan Orogenic belt.Mesoproterozoic Archean zircon may have been transported from the inner Cathaysia Plate to the Yangtze Plate.It is further proved that there is no sedimentary barrier between the Cathaysia plate and the Yangtze plate in the Paleozoic era,and it is a whole plate.The Danlin Formation was deposited in a cra-ton basin in the South China block.
万方数据
维普
