Three-dimensional conductivity model of crust and uppermost mantle at   the northern Trans North China Orogen: Evidence for a mantle source of   Datong volcanoes

doi:10.1016/j.epsl.2016.08.025

CORC > 北京大学 > 地球与空间科学学院

	Three-dimensional conductivity model of crust and uppermost mantle at the northern Trans North China Orogen: Evidence for a mantle source of Datong volcanoes
	Zhang, Huiqian ; Huang, Qinghua ; Zhao, Guoze ; Guo, Zhen ; Chen, Y. John
刊名	EARTH AND PLANETARY SCIENCE LETTERS
	2016
关键词	3-D MT inversion high conductivity anomalies Datong volcanoes North China Craton Trans North China Orogen CONTINENTAL-CRUST MAGNETOTELLURIC DATA TAIHANG MOUNTAINS WAVE TOMOGRAPHY WATER-CONTENT U-PB CRATON BENEATH INVERSION EVOLUTION
DOI	10.1016/j.epsl.2016.08.025
英文摘要	While the Eastern Block of North China Craton (NCC) had experienced significant lithospheric destruction in the Mesozoic, the Western Block of NCC and the Trans North China Orogen (TNCO) have undergone localized lithospheric modification since the Cenozoic. The northern TNCO is highlighted by the Cenozoic magmatic activities including Hannuoba basalts and Datong volcanoes and is a seismically active region. In this study 3-D electrical conductivity model of the crust and uppermost mantle is derived by the 3-D inversion technique using data from 72 broadband magnetotelluric (MT) stations. The final model shows that a 15 km thick resistive layer of about 3000 Omega m dominates the upper crust, which may represent the intact Archean and Paleoproterozoic terrains. Whereas in the mid-crust there are marked high conductivity anomalies of about 10 Omega m beneath Shanxi rifting basin, which may result from the interconnected saline fluid of 0.2% to 6% volume fraction. The most important finding is that one significant conductor extended into the mantle is located between Hannuoba field and Datong volcanoes and it connects with the mid-crust conductor beneath the Datong volcanoes. We suggest that this could be the mantle source (partial melting region) for the Quaternary volcanic activities of Datong volcanoes and the melt fraction is estimated as 6.6%. Its location inside the Western Block suggests that the volcanic activities at Datong volcanoes are irrelevant to the tectonic process to the east of TNCO. It is likely to be related to the mantle flows from the Tibetan Plateau around the Ordos block which converges at the northeastern corner of the Ordos block and local upward flow along the slope of the thinning lithosphere resulted in decompression partial melting and the melt percolated upward through the crust to feed the lava eruptions at the Datong volcanoes to the east. Finally, large crustal earthquakes in this region are generally located in resistive zones with high conductivity anomalies beneath. The fluids brought up by hot mantle material may play an important role in fault strength weakening and rupture nucleation at mid-crust depths. (C) 2016 Elsevier B.V. All rights reserved.; National Natural Science Foundation of China [41274075, 41374077]; National Basic Research Program of China [2014CB845903]; SCI(E); ARTICLE; huangq@pku.edu.cn; 182-192; 453
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/456888]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhang, Huiqian,Huang, Qinghua,Zhao, Guoze,et al. Three-dimensional conductivity model of crust and uppermost mantle at the northern Trans North China Orogen: Evidence for a mantle source of Datong volcanoes[J]. EARTH AND PLANETARY SCIENCE LETTERS,2016.
APA	Zhang, Huiqian,Huang, Qinghua,Zhao, Guoze,Guo, Zhen,&Chen, Y. John.(2016).Three-dimensional conductivity model of crust and uppermost mantle at the northern Trans North China Orogen: Evidence for a mantle source of Datong volcanoes.EARTH AND PLANETARY SCIENCE LETTERS.
MLA	Zhang, Huiqian,et al."Three-dimensional conductivity model of crust and uppermost mantle at the northern Trans North China Orogen: Evidence for a mantle source of Datong volcanoes".EARTH AND PLANETARY SCIENCE LETTERS (2016).