U–Pb age and Hf isotope composition of detrital zircons from Neoproterozoic sedimentary units in southern Anhui Province, South China: Implications for the provenance, tectonic evolution and glacial history of the eastern Jiangnan Orogen

2015 ◽  
Vol 271 ◽  
pp. 65-82 ◽  
Author(s):  
Xiang Cui ◽  
Wenbin Zhu ◽  
I.C.W. Fitzsimons ◽  
Jingwen He ◽  
Yuanzhi Lu ◽  
...  
Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 333 ◽  
Author(s):  
Wei Liu ◽  
Xiaoyong Yang ◽  
Shengyuan Shu ◽  
Lei Liu ◽  
Sihua Yuan

Zircon U–Pb dating and Hf isotopic analyses are performed on clastic rocks, sedimentary tuff of the Dongchuan Group (DCG), and a diabase, which is an intrusive body from the base of DCG in the SW Yangtze Block. The results provide new constraints on the Precambrian basement and the Late Paleoproterozoic to Mesoproterozoic tectonic evolution of the SW Yangtze Block, South China. DCG has been divided into four formations from the bottom to the top: Yinmin, Luoxue, Heishan, and Qinglongshan. The Yinmin Formation, which represents the oldest rock unit of DCG, was intruded by a diabase dyke. The oldest zircon age of the clastic rocks from the Yinmin Formation is 3654 Ma, with εHf(t) of −3.1 and a two-stage modeled age of 4081 Ma. Another zircon exhibits an age of 2406 Ma, with εHf(t) of −20.1 and a two-stage modeled age of 4152 Ma. These data provide indirect evidence for the residues of the Hadean crustal nuclei in the Yangtze Block. In combination with the published data, the ages of detrital zircons from the Yinmin Formation yielded three peak ages: 1.84, 2.30 and 2.71 Ga. The peaks of 1.84 and 2.71 Ga are global in distribution, and they are best correlated to the collisional accretion of cratons in North America. Moreover, the peak of 1.84 Ga coincides with the convergence of the global Columbia supercontinent. The youngest age of the detrital zircon from the Yinmin Formation was 1710 Ma; the age of the intrusive diabase was 1689 ± 34 Ma, whereas the weighted average age of the sedimentary tuff from the Heishan Formation was 1414 ± 25 Ma. It was presumed that the depositional age for DCG was 1.71–1.41 Ga, which was in accordance with the timing of the breakup of the Columbia supercontinent. At ~1.7 Ga, the geochemical data of the diabase were characterized by E-MORB and the region developed the same period A-type granites. Thus, 1.7 Ga should represent the time of the initial breakup of the Yangtze Block. Furthermore, the Yangtze Block continues to stretch and breakup until ~1.4 Ga, which is characterized by the emergence of oceanic island, deep-sea siliceous rock and flysch, representing the final breakup. In brief, the tectonic evolution of the Yangtze Block during the Late Paleoproterozoic to Mesoproterozoic coincided with the events caused by the convergence and breakup of the Columbia supercontinent, because of which, the Yangtze Block experienced extensive magmatic activity and sedimentary basin development during this period.


Tectonics ◽  
2018 ◽  
Vol 37 (4) ◽  
pp. 1063-1076 ◽  
Author(s):  
Yi Yan ◽  
Deng Yao ◽  
Zhixian Tian ◽  
Chiyue Huang ◽  
Wenhuang Chen ◽  
...  

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 936
Author(s):  
Tae-Ho Lee ◽  
Kye-Hun Park

There was a hiatus in magmatism in Korea and Japan, located on the eastern continental margin of Asia, during a period of about 40 Ma from 160 Ma to 120 Ma. The cause of the resumption of magmatism since then is not yet well understood. In this study, we analyzed the Hf isotope composition of detrital zircons in the Cretaceous sediments of Korea (Hayang Group) and Japan (Goshoura and Himenoura groups) to investigate the tectonic evolution of eastern Asia in the Early Cretaceous period. εHf(t) in Cretaceous zircons from Japanese samples values from +8.2 to +0.1, suggesting that magmatism was sourced from the depleted juvenile materials, which is compatible with ridge subduction and subsequent melting of the young oceanic crust. εHf(t) values from Cretaceous zircons in the Hayang Group are negative, except for the Jindong Formation, which had a sediment supply from Japan, indicating that the old continental crust material of the Korean Peninsula was included in the magma generation. The detrital zircons of this study exhibit a depleted isotopic character at the beginning of subduction-related magmatism in Permian and Early Cretaceous, and then gradually change to a more enriched composition. This trend may be a typical example of the Pacific-type orogenic cycle.


2017 ◽  
Vol 155 (6) ◽  
pp. 1377-1393 ◽  
Author(s):  
LONGMING LI ◽  
SHOUFA LIN ◽  
JIANHUA LI ◽  
JIAN HE ◽  
YANPENG GE

AbstractU–Pb ages and Hf isotope compositions of zircons from the Chencai complex in Zhejiang Province have been determined to provide constraints on mechanisms of migmatization and tectonic evolution related to the early Palaeozoic orogeny in the Cathaysia Block, South China. Zircons from leucosome samples of migmatites are characterized by nebulous overgrowths enclosing inherited cores or occur as newly formed grains with weak zoning. Five samples gave weighted mean ages ranging from 438±3 Ma to 432±4 Ma, which are interpreted as recording the time of anatexis of a regional tectono-thermal event. TheirεHf(t) values range from −21.4 to −4.8 (with peak at −11), with correspondingTDM2ages of 1.73–2.77 Ga (with peak atc.1.9–2.3 Ga), suggesting that the protoliths formed by reworking of ancient crust evolved from Late Palaeoproterozoic – early Archaean crust–mantle differentiation. The migmatization was spatially and temporally associated with reported 460–435 Ma metamorphism with a clockwise pressure–temperature (P–T) path and was most likely controlled by crustal thickening driven by the early Palaeozoic orogenesis. TheTDM2ages of the Chencai complex are consistent with those of the Wuyi–Yunkai structural belt in the Cathaysia Block, but distinct from those (with peak at 2.7–3.0 Ga) of the Badu complex which lacks early Palaeozoic tectono-thermal records. The data support the suggestion that a postulated geological entity, instead of the east domain (the Badu complex being its main part) of the Cathaysia Block, was probably involved in the early Palaeozoic orogeny.


2021 ◽  
Vol 62 (3) ◽  
pp. 1-12
Author(s):  

To constrain the paleo - positions of the South China Cratons in the Rodinia Supercontinent during the Neoproterozoic, the in - situ U - Pb dating, and Hf isotope analysis of the detrital zircon from the Nam Co Complex, Song Ma Suture zone, northwestern Vietnam was performed. The U - Pb isotopic dating on detrital zircons shows that the Nam Co Complex demonstrates the major population (>50%) of around ~850 Ma while the minor population is scattered between ~1.2÷3.0 Ga. The Neoproterozoic age spectrum exhibits a large range of the εHf(t) from strongly negative to positive values ( - 17.418022÷ 14.600527), indicating that the source of the magma for this age range has been not only derived from reworking of the Archean basement rocks, but also generated from the juvenile material. The U - Pb age distribution patterns and Hf isotopic data of the detrital zircon in the Nam Co Complex are compatible with those of the South China Craton rather than those of the Indochina Craton. The data also indicate that sedimentary protoliths of the Nam Co Complex were deposited in a convergent - related basin along the southwestern margin of the South China Craton during the Neoproterozoic. Combined with the similarities of the detrital zircon age between western Cathaysia, Indochina, East Antarctica and East India, it is proved that the South China Craton was situated at the margin of the Rodinia Supercontinent and in close proximity to the Indochina, East Antarctica and East India.


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