Chen B.,Changan University |
Xia M.-Z.,Changan University |
Xia M.-Z.,Key Laboratory of Western China Mineral Resources and Geological Engineering |
Wang B.-Y.,Changan University |
And 2 more authors.
Kuangwu Yanshi/ Journal of Mineralogy and Petrology | Year: 2011
Controlled by the Kangurtag-Huangshan ductile sheer zone, the Huangshan intrusion is located in the central segment of Tudun-Huangshan-Tulaergen mafic-ultramafic rock belt, the northern section of the East Tianshan. The intrusion is characteristic of tholeiitic series and composed of peridotite, olivine pyroxenites, lherzolite, olivine gabbronorite, gabbros and gabbros-diorite. They are enriched in large ion lithophile elements (such as Rb, Ba, Sr) and depleted in high field strength elements (such as Nb, Ta, Ti). The εNd(t) value of the rocks ranges from +4. 1 to + 9. 2 and the εSr,(t) value of most rocks from -22. 5 to -4. 5 except for three samples with the εSr(t) value of +2. 2, +12. 5 and +15. 4 respectively. Nd, Sr isotopic compositions indicate that the magma was derived from depleted mantle. The initial 206 Pb/204 Pb, 207Pb/204 Pb and 208Pb/204 Pb is 18.08 -18. 413,15. 441-15. 513 and 37. 461 6-37. 899 respectively, indicating the MORB-affinity. Pétrographie and lithogeochemical analysis suggests that the magma was experienced fractional crystallization of olivine, orthopyroxene, clinopyroxene and plagioclase and was subjected to crust assimilation contamination to a certain extent in the late stages of magmatic evolution. Characters of element geochemistry and Nb,Sr,Pb isotope shows that the magma source is composed of asthenosphere components combined with enriched lithospheric mantle. Huangshan intrusion is t resulted from the lithospheric delamination at the root and the upwelling of asthenosphere components, corresponding to post-collision extension setting. Source
Peng J.,Changan University |
Peng J.,Key Laboratory of Western China Mineral Resources and Geological Engineering |
Qiao J.,Changan University |
Leng Y.,Changan University |
And 2 more authors.
Environmental Earth Sciences | Year: 2016
Wei River Basin (WRB) is the origin of the ancient and new Silk Road, and it is located in Southern Fen Wei Graben System, China. Since 1950s, hundreds of ground fissures have formed in this affluent basin, and these ground fissures have become the main geohazard in WRB. This paper used a series of geological investigations, such as site investigation, trench excavation, geological drilling and geophysical survey to understand the distribution and mechanism of formation of the ground fissures in WRB. The results are: (1) 212 ground fissures in WRB were located in Xi’an, Xianyang, Weinan city, and they have clear orientations, mainly distributed from NEE to SWW, NW to SE, and E to W. Moreover, the ground fissures are accompanied by active faults along the same directions. (2) Ground fissures in WRB can be divided into two types—some ground fissures display obvious horizontal and vertical separations on the earth surface, whereas others only display obvious horizontal separations on the earth surface. (3) Ground fissures in WRB are triggered by four factors, viz. basin structure, active fault, human activities and loess erosion. (4) The mechanism for the formation of ground fissures has also been proposed: tectonic faulting is the fundamental cause of ground fissures in the Wei River basin, and imbalances in the man-land caused by human actives accelerated the ground fissures activities. (5) Many effective measures have also been proposed to mitigate the hazards of ground fissures in WRB, such as planning, engineering measures, controlling the exploitation of groundwater and monitoring. This research will be helpful in safeguarding the sustainable development of the Silk Road economic belt. © 2016, Springer-Verlag Berlin Heidelberg. Source
Yang C.,Changan University |
Yang C.,Key Laboratory of Western China Mineral Resources and Geological Engineering |
Zhang Q.,Changan University |
Zhang Q.,Key Laboratory of Western China Mineral Resources and Geological Engineering |
And 5 more authors.
Mining Science and Technology | Year: 2010
For harmful ground collapse and its special deformation characteristics, which causes SAR images to lose coherence, InSAR technology cannot be applied in monitoring surface collapse in mining areas. We took the Shenmu mining area in northern Shaanxi province as an example to study subsidence in mining areas and proposed an interpolated multi-view processing method. The results show that this method can improve the detectable deformation gradient to a certain extent and can become a good reference value for monitoring large scale gradient deformation. We also analyzed the rules for temporal decorrelation in mining. © 2010 China University of Mining and Technology. Source