[Scientific Research Progress] New understanding of the background of the old constructor in the southeast edge of the southeast of the South China sector

The South China sector was made up of the Yangtze Plate and the Huaxia sector in the early New Yuan Dynasty. With the opening of Guttisha during the early-Mid-Mud Pen Pen Pen Pen Pen Pen Pen, the South China sector was isolated from the east of the Pantaea near the ancient equator, until the intercourse of the Trinity-Three Stacks and the North China sector finally collided with a combination. Essence

Due to the unique ancient geographical location of the South China sector during the late Period, the structural environment of its southeast edge is of important scientific significance for understanding the structural dynamic state on the east side of the Pan -Mainland. Because of the extensive development of carbonate in the same period, and lack of significant records of magma, constructive effects, and deterioration effects, the southeast edge of the South China sector has always been considered a stable passive continental edge structural environment.

However, in recent years, a large number of late ancient age crumbs are reported to exist in the dilayer -Trinity debris sedimentary rocks, indicating that this section has significant magma activities during this period. At present, a large number of debris vermiculite research has been carried out for the Pot Basin -Early Stone Charcoal World and Early Two -Stacking World -Triple Period Story. The critical period gathered in the late stone charcoal world. At present, there are three main modes of disputes: (1) its structural environment has transformed from the passive continental environment of Carbon Period to the activity environment of the event of the Early Two -over. The constructive environment related to the valley.

Due to the limited sedimentation of late stone charcoal fragmented rocks, the research work of debris vermiculite has not been carried out systematically, to a certain extent, we have limited our understanding of the construction environment and ancient geographical evolution of the Western Plate of the South China.

Study Zone Construction-Ancient Geographical Outline Map and Rock Column Chart and Featured Sandstone Photos

Recently, Researcher Chen Jitao, an associate researcher of the co -team Zheng Qingfeng, Dr. Huang Xing and doctoral student Xin Hao, the co -team, etc. The hybrid deposition sequence of acid rocks and debris rocks has carried out comprehensive research such as deposition, biological stratigraphy, dandruff vexeshumin U-PB annual year, vermiculite trace element test, and HF isotope test. The study of the ancient constructor environment of the late ancient generation of the southeast edge of the South China sector has been studied, and the construction environment and geological dynamic model of the late ancient generation of the southeast edge of the South China sector were established. The results are recently published in the world -renowned journal "Geophysical Research Letters".

Comprehensive diagram of the southeast edge of the South China sector

(A) The weighted average age of the youngest fragmented stones; (b) the discrimination map of the structure environment of the crumbs; ;

The research is mainly based on the analysis of the material of the debris. The results show that the debris sediments are mainly derived from the Chinese ancient land on the southeast side of the research area. Combined with the youngest data of the dandruff gangsters and the limited biological strata, it reveals that the rock body of the material area is rapidly lift up at about 318.5 mA. Through the diligang HF isotope data, and combined with the crustal thickness data calculated based on trace elements, the South China sector is continuously dismantled in the middle -the late ancient crustal material, which leads to the reduction of the thickness of the crust.

Southeast edge structure pattern diagram of the southeast of the South China plate

Based on this new discovery and existing understanding, the study proposed that the Northeast edge of the southeast of the South China sector has been at the convergence of the edge environment of the dive, and due to its heat disturbance, the thickness of the crust is continuously thinned, and the ancient geographical appearance gradually gentle. In addition, the study is also of great significance to understand the time and space distribution of mining resources such as the evening pale aluminum ore and carbonate rock -controlled uranium -controlled uranium -controlled uranium -controlled uranium, and will help further guide the exploration of mineral resources.

The study was jointly funded by the National Academy of Sciences, the National Natural Science Foundation of China, and the National Natural Science Foundation of China and the National Key Laboratory of Modern Paramissions and Strangers.

◎ Thesis related information:

Gao, B., Chen, J.T.*, Huang, X., Xin, H., and Zheng, Q.F. (2022), Resolving the tectonic setting of South China in the late Paleozoic, Geophysical Research Letters. First published: 04 August 2022 Then, then, then

https://doi.org/10.1029/2022GL099809.

Copywriting | Chen Jitao (Nanjing Institute of Geological Paradosure of Chinese Academy of Sciences)

Capture Edit | Liu Yun

Copywriting review | Chen Xiaogen

- END -