Provenance analysis of the Liantuo Formation in Dahongshan area, the notrhern Yangtze Block: evidence from sedimentology and detrital zircon U-Pb chronology

Key words: 
• Yangtze Block /
• Neoproterozoi /
• Liantuo Formation /
• Detrital zircon /
• Paleo-flow direction

Abstract: The Liantuo Formation is a key mid-Neoproterozoic stratigraphic unit in the Dahongshan area of Yangtze Block, South China. Its deposition time is coupled with the breakup of the Rodinia supercontinent, and it is the last sedimentary layer before the Sturtian ice Age of the first snowball Earth. However, its deposition time and provenance need to be further studied and to provide fundamental support for dissecting these major geological historical events. Here, we analyzed detrital zircons U-Pb chronology from Liantuo Formation sandstone in this area, which shows sedimentary time is ca. 800-714 Ma and major peaks of detrital zircons are ca. 2500 Ma, ca. 2000 Ma, ca. 880 Ma, and ca. 820 Ma, and the secondary peaks are ca.780 Ma. Combined with the characteristics of paleo-flow direction, gravel composition, and sedimentary facies distribution analysis, the provenance of the Liantuo Formation in the study area is from the depositional recycle of the Dagushi Group and Huashan Group in the lower strata and the Archean to Neoproterozoic magmatic rocks in the northern Yangtze Block, and it is mainly from the northeast direction of the study area. Meanwhile, the western Hubei, southeastern Hubei to northwestern Jiangxi, southwest Hubei to northern Hunan, and Dahongshan of the northern Hubei areas have similar detrital zircon age peaks of Archean, Paleoproterozoic, and Neoproterozoic. And according to the distribution characteristics of magmatic rocks in the north and southeast margin of the Yangtze Block, which suggests that the provenance of the Liantuo Formation in the northern Yangtze Block has a north-northeast supply.