Considerable debate on whether and how the Sulu Orogenic Belt extends eastward to the Korean Peninsula has rem...
Mingguo Zhai~(a,b,*),Jinghui Guo~(a,b),Zhong Li~a,Daizhao Chen~a,Peng Peng~a,Tiesheng Li~a, Quanlin Hou~c,Qicheng Fan~d a Institute of Geology and Geophysics,and Key Laboratory of Mineral Resources,Chinese Academy of Sciences,Beijing,100029,China b Chinese State Key Laboratory of Lithosphere Evolution,China c Graduate University,Chinese Academy of Sciences,China d Institute of Geology,Chinese Seismological Bureau,China
Recent studies suggest that the South China Block(SCB) was located at a central position in the Neoproterozoic...
Mingguo Zhai~(1*),Ji’an Shao~2,Jie Hao~1 and Peng Peng~1 1 Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing,100029, China, 2 Department of Geology,Peking University,Beijing,China
SHRIMP U-Pb zircon dating on the Xileketehalasu granodiorite porphyry and Kalasayi monodiorite porphyry that intrude middle Devonian Beitashan Formation at the north part of east Junggar region shows that they were formed at 381±6 Ma and 376±10 Ma respectively. They are interpreted as subduction-related granitic rocks, which is the first report that the isotopic ages for the granitic rocks range from 350 to 390 Ma. Another determined age for the Kalasayi monodiorite porphyry is 408±9 Ma, representing the age of underlain Lower Devonian volcanic rocks. Thus, the U-Pb dates suggest that the northeastward subduction of Junggar ocean from southwest occurred at 408 to 376 Ma (the real inter- val may be larger). Because the ore-bearing porphyry intruded following the formation of the volcanic rocks of middle Devonian Beitashan Formation, their tec- tonic setting is similar to the Andes Mountains that hosts world-class porphyry copper deposits, and the researched area could be regarded as a potential area for prospecting large porphyry copper deposits.
The global collisional orogenic events (e.g. Grenvil-lian or Pan-African event) have occurred for several times since 2.5 billion years (Ga) ago, which has led Earth scientists to speculate that continental landmasses have periodically assembled and dispersed, resulting in the assembly and breakup of supercontinent. In the last decade, the reconstruction of ancient supercontinents has been focused on Rodinia, a defined supercontinent that was assembled along the -1.0 Ga "Grenvillian" oro-gens. In reconstructing Rodinia, however, Earth scientists have noticed that not all continental blocks in the supercontinent were welded by the -1.0 Ga orogenic belts (fig. 1(a)), and that most blocks welded by the 1.0 Ga orogens contain abundant evidence that they are a
