Lithospheric modification at the onset of the destruction of the North China Craton: Evidence from Late Triassic mafic dykes
Lithospheric modification at the onset of the destruction of the North China Craton: Evidence from Late Triassic mafic dykes
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华北克拉通破坏开始时的岩石圈改造：来自晚三叠世基性岩脉的证据
DOI：
10.1016/j.chemgeo.2021.120105
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发表时间：
2021-04
期刊：
影响因子：
3.9
通讯作者：
Jinlong Dong
中科院分区：
文献类型：
--
作者：
Chao Wang;Shuguang Song;Li Su;Mark B. Allen;Jinlong Dong
幔源岩浆活动为理解岩石圈减薄机制提供了重要的认识。本文报道了华北北方冀东地区晚三叠世基性岩墙的年代学和地球化学综合研究结果。原位锆石U-Pb定年结果表明，这些岩墙侵位于238 ~ 223 Ma之间，高家店岩墙和马台子岩墙侵位于238-234 Ma，沙河桥岩墙侵位于223 ± 4 Ma（2s）。块状岩石地球化学研究表明，冀东晚三叠世岩墙是由石榴子石-尖晶石过渡带（约70-80 km）内的岩石圈地幔熔融，并受到上涌的软流圈加热而形成的。这个古老的岩石圈地幔在以前的俯冲事件中被交代。高家店和马台子岩脉是在略低于萨河桥岩脉的压力下，由较高程度的部分熔融形成的。冀东晚三叠世岩墙的熔融深度表明，到晚三叠世，完整的古代岩石圈地幔至少已局部改造/减薄至~70-80 km。这些晚三叠世岩墙的侵入发生在华北陆壳岩石圈减薄的开始阶段，这是由俯冲和相邻地块与华北陆壳碰撞后的碰撞后伸展造成的。
Mantle-derived magmatism provides important insights for understanding the mechanism of lithospheric thinning. Here we report the results of an integrated geochronological and geochemical study of Late Triassic mafic dykes in Eastern Hebei, northern North China Craton. In situ zircon U-Pb dating shows that the dykes were emplaced between 238 and 223 Ma; the coeval Gaojiadian and Mataizi dykes intruded Precambrian basement at 238–234 Ma and the Saheqiao dyke was emplaced into Neoarchean supracrustal rocks later at 223 ± 4 Ma (2s). Bulk-rock geochemistry indicates that the Late Triassic dykes in Eastern Hebei were produced by melting of ancient lithospheric mantle within the garnet-spinel transition zone (~70–80 km), heated by upwelling asthenosphere. This ancient lithospheric mantle had been metasomatized during previous subduction events. The Gaojiadian and Mataizi dykes resulted from higher degrees of partial melting at slightly lower pressures than the Saheqiao dyke. The melting depth of Late Triassic dykes in Eastern Hebei indicates that the intact ancient lithospheric mantle had been at least locally modified/thinned to ~70–80 km by the Late Triassic. The intrusion of these Late Triassic dykes took place at the onset of the lithospheric thinning of the North China Craton, caused by post-collisional extension after subduction and collision of neighboring blocks with the North China Craton.
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影响因子：
3.9
作者：
Yue-heng Yang;Fu-Yuan Wu;S. Wilde;Xiaoming Liu;Y. Zhang;Liewen Xie;Jin-Hui Yang
通讯作者：
Yue-heng Yang;Fu-Yuan Wu;S. Wilde;Xiaoming Liu;Y. Zhang;Liewen Xie;Jin-Hui Yang
影响因子：
3.8
作者：
Yu‐Sheng Zhu;Jin-Hui Yang;Hao Y. C. Wang;Fu-Yuan Wu
通讯作者：
Yu‐Sheng Zhu;Jin-Hui Yang;Hao Y. C. Wang;Fu-Yuan Wu
影响因子：
3.5
作者：
Herzberg, C.;Asimow, P. D.
通讯作者：
Asimow, P. D.
DOI：
10.1016/s0419-0254(99)80014-7
发表时间：
1999
期刊：
Developments in Geotectonics
影响因子：
--
作者：
T. Furman;D. Graham
通讯作者：
T. Furman;D. Graham
DOI：
10.1007/bf02911949
发表时间：
2000-12
期刊：
Science in China Series D: Earth Sciences
影响因子：
--
作者：
J. Shao;Qingjun Han;Hui-ming Li
通讯作者：
J. Shao;Qingjun Han;Hui-ming Li