Detrital zircon of 4.1 Ga in South China

Yajun Xu,Wenchao Yu,Yuansheng Du,Zhiqiang Huang,Yanhui Zhu,Lisha Hu,Hongwei Huang

doi:10.1007/s11434-012-5465-8

Abstract

One hadean zircon from the Cambrian sandstone in the southern part of South China has a U-Pb age of 4107±29 Ma with ɛ Hf(t) value similar to that of the homochronous depleted mantle and Hf model age of 4102±21 Ma. This demonstrates the existence of hadean crustal remnant in South China. A close match between the U-Pb age and Hf model age with the highly position ɛ Hf(t) value indicates the growth and immediate reworking of juvenile crust from the depleted mantle at ca 4.1 Ga. The prominent “Pan-African” and Grenville zircons derived from the exotic sources were also found in the sample, which indicates a linking between South China and Gondwana in the Cambrian period. The southern part of South China has complex histories of crustal growth and tectonic evolution.

Highlights

State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China; Guangxi Bureau of Geology, Mineral Prospecting and Exploitation, Nanning 530023, China
One hadean zircon from the Cambrian sandstone in the southern part of South China has a U-Pb age of 4107±29 Ma with εHf(t) value similar to that of the homochronous depleted mantle and Hf model age of 4102±21 Ma
“Pan-African” and Grenville zircons derived from the exotic sources were found in the sample, which indicates a linking between South China and Gondwana in the Cambrian period

Summary

Location and description of sample

Sample was collected from the West Daming Mountain in the western part of Nanning City, Guangxi Province, where tectonically belong to the Cathaysia Block, the South China. Daming Mountain are the Lower Cambrian Xiaoneichong and Middle-Upper Cambrian Huangdongkou formations. The Xiaoneichong Formation is composed mainly of mid-thick pale-green quartz sandstone interbedding with mudstone, with the volume of mudstone increasing upwards. The Huangdongkou Formation consists mainly of pale-green quartz sandstone intercalated with mudstone. The succession is overlain unconformably by the. Sample 11FS-3 from the Xiaoneichong Formation is a pale-green quartz sandstone with the angular, variable grain texture.

Analytical methods

Findings

Discussion and conclusions