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Your search keyword '"Feng, Qinglai"' showing total 2 results
Start Over Author "Feng, Qinglai" Topic zircon Region yunnan sheng (china)
2 results on '"Feng, Qinglai"'

1. Detrital Zircon of Devonian Sandstones in Changning-Menglian Suture Zone, Yunnan, SW China: Implications for the Early Evolution of Paleo-Tethys.

Author

Gan, Zhengqin, Feng, Qinglai, Wei, Yuehua, Liu, Guichun, Nie, Xiaomei, and Zhao, Tianyu

Subjects
*SUTURE zones (Structural geology), *DEVONIAN Period, *ZIRCON, *SANDSTONE, *ISLAND arcs, *TURBIDITES, *AGE groups
Abstract

The Changning-Menglian suture zone is a critical tectonic belt pivotal to the evolution of the Paleo-Tethys. The Wenquan Formation, characterized as turbidite deposited on the western side of the Changning-Menglian suture zone as well as the eastern edge of the Baoshan Block. Analysis of detrital zircons from the Wenquan Formation reveals two significant age peaks approximately at 440 and 980 Ma, with additional age populations around 600, 780, and 2 500 Ma. The major age peak at about 440 Ma is come from the andesitic-dominant volcanic arc within the Lancang Block and the western Simao Block, corroborated by the presence of andesite fragments in thin section studies. Meanwhile, the zircons that form the secondary age peak at ∼980 Ma and other older age groups probably originate from the Baoshan Block. Deposited on the western side of the Paleo-Tethyan ophiolites, the Wenquan Formation received detrital materials from the continental margin on the opposite side. Thus, the main Paleo-Tethyan Ocean basin was not sufficiently broad enough to cut off the transference of detrital materials. It was a relatively narrow basin in the Early Devonian. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Tracking Prototethyan assembly felsic magmatic suites in southern Yunnan (SW China): evidence for an Early Ordovician–Early Silurian arc–back-arc system.

Author

Liu, Guichun, Chen, Guangyan, Santosh, M., Qian, Xin, Sun, Zaibo, Zi, Jian-Wei, Zhao, Tianyu, Feng, Qinglai, and Ma, Shen

Subjects
IGNEOUS rocks, PALEOZOIC Era, GRANITE, AMPHIBOLITES, ZIRCON
Abstract

Early Paleozoic trondhjemites, gneissic granites and alkali granites in southern Yunnan preserve important records of the tectonic evolution of the Prototethyan Ocean and regional correlations. Zircon ages suggest that these granitoids were emplaced from 476 to 436 Ma. The trondhjemites are characterized by high Na2O and low K2O contents, with εNd(t) values of −1.9 to −3.5 and εHf(t) values of −2.8 to +3.9. The trondhjemites were derived from an amphibolite source with a juvenile mafic component. The gneissic granites belong to the metaluminous low-K calc-alkaline series with an εNd(t) value of −6.2 and εHf(t) values of −5.0 to −0.4. The alkali granites belong to the high-K calc-alkaline series and yield εNd(t) values of −10.1 to −10.7 and εHf(t) values of −7.9 to −2.3. The gneissic granites were derived from an 'ancient' lower mafic crust, whereas the alkali granites were derived from a meta-sedimentary source. These granitoids were formed during the subduction of the Prototethyan Ocean beneath the Simao Block and can be compared with similar igneous rocks from the Truong Son and Tam Ky-Phuoc Son zones in southern Laos. Our study, along with Early Paleozoic igneous suites from southern Laos, central Vietnam and the Malay Peninsula, suggests an arc–back-arc system along the northern margin of Gondwana. Supplementary material: Tables of zircon U–Pb and in-situ Hf and geochemical data are available at https://doi.org/10.6084/m9.figshare.c.5322386 [ABSTRACT FROM AUTHOR]

Published
2021
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