Partial melting of the South Qinling orogenic crust, China: Evidence from Triassic migmatites and diorites of the Foping dome
Partial melting of the South Qinling orogenic crust, China: Evidence from Triassic migmatites and diorites of the Foping dome
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中国南秦岭造山地壳的部分熔融：来自佛坪穹窿三叠纪混合岩和闪长岩的证据
DOI：
10.1016/j.lithos.2016.05.007
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发表时间：
2016-09
期刊：
影响因子：
3.5
通讯作者：
Chen Fukun
中科院分区：
文献类型：
--
作者：
Zhang He;Ye Ri-Sheng;Liu Bing-Xiang;Wang Yan;Zhang Yuan-Shuo;Siebel Wolfgang;Chen Fukun
The Qinling orogen was ultimately formed by suturing of the South Qinling and Yangtze blocks, but the exact timing of the final amalgamation of the two blocks has not been well established so far. Partial melting of the Qinling orogenic continental crust resulted in the generation of migmatites, and such rocks may help to decipher the chronology of such event. In this paper, we report U–Pb ages, trace element, and Hf isotopic compositions of zircons from migmatites and diorite gneisses of the Foping dome, South Qinling. Zircons from migmatites form anhedral grains of variable sizes that are characterized by complex trace element compositions. Based on zircon U–Pb ages, the migmatites can be subdivided into two groups: Group 1 migmatites mainly retain Triassic zircons with U–Pb ages of 214–211 Ma and Hf model ages of ~ 1.46 Ga in core and rim domains; zircons from Group 2 migmatites record both Triassic (~ 210 Ma) and Neoproterozoic U–Pb ages, analogous to igneous rocks of the Wudang and Yaolinghe Groups exposed in South Qinling. Zircons from the diorite gneisses yield U–Pb ages of 216–210 Ma with Hf isotopic composition (TDM2ages of ~ 1.46 Ga) similar to the migmatites. Evidence from whole-rock Nd isotopic analyses also points to a similar genesis between migmatites and diorite gneisses. It is proposed that Group 1 migmatites were derived by melting of Triassic diorites, while Group 2 migmatites were derived from Neoproterozoic igneous rocks, a major basement lithology of South Qinling. Partial melting of the orogenic crust took place at ~ 214–210 Ma, approximately consistent with the retrograde metamorphism of granulites exposed along the suture zone between the South Qinling and Yangtze blocks. We suggest that the collision of these two blocks occurred prior to ~ 215 Ma and that the Foping dome resulted from rapid collapse of an overthickened crust followed by partial melting enhanced by asthenospheric influx.
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影响因子：
5
作者：
Hoskin, PWO
通讯作者：
Hoskin, PWO
影响因子：
3.5
作者：
Hao Cheng;Chao Zhang;J. Vervoort;Xian‐Hua Li;Qiu-li Li;Y. Wu;Shu Zheng
通讯作者：
Hao Cheng;Chao Zhang;J. Vervoort;Xian‐Hua Li;Qiu-li Li;Y. Wu;Shu Zheng
影响因子：
4.5
作者：
Geisler, Thorsten;Schaltegger, Urs;Tomaschek, Frank
通讯作者：
Tomaschek, Frank
DOI：
10.1144/gsl.sp.1986.019.01.05
发表时间：
1986
期刊：
Geological Society, London, Special Publications
影响因子：
--
作者：
P. England;A. Thompson
通讯作者：
P. England;A. Thompson
DOI：
10.1002/cjg2.3373
发表时间：
2003-05
期刊：
Chinese Journal of Geophysics
影响因子：
--
作者：
Shunyou Cheng;Guo‐Wei Zhang;L. Li
通讯作者：
Shunyou Cheng;Guo‐Wei Zhang;L. Li