DOI: 10.1007/s00531-015-1160-8
Scopus记录号: 2-s2.0-84931560694
论文题名: Microstructural and mineral analysis on the fault gouge in the coseismic shear zone of the 2008 Mw 7.9 Wenchuan earthquake
作者: Yuan R.-M. ; Zhang B.-L. ; Xu X.-W. ; Lin C.-Y. ; Han Z.-J.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2015
卷: 104, 期: 5 起始页码: 1425
结束页码: 1437
语种: 英语
英文关键词: Fault gouge
; Microstructure
; Mineral component
; The 2008 Wenchuan earthquake
Scopus关键词: coseismic process
; earthquake rupture
; fault gouge
; fault zone
; illite
; microstructure
; mineralogy
; montmorillonite
; seismic zone
; shear zone
; Sichuan earthquake 2008
英文摘要: The 2008 Mw 7.9 Wenchuan earthquake formed two coseismic surface rupture zones with the trend of N35°E, known as the Beichuan–Yingxiu rupture and the Pengguan rupture. The Beichuan–Yingxiu rupture is the principle one with abundant fault gouge development along its length. In the exploratory trench at the Saba village along the Beichuan–Yingxiu rupture, the new fault gouge zone is only ~3 mm wide, which suggests that fault slip was constrained in a very narrow zone. In this study, we thus carried out detailed microstructural and mineral component analysis on the oriented fault gouge samples from the Saba exploratory trench to understand their features and geological implication. The results show that different microstructures of localized brittle deformation can be observed in the fault gouges, including Y-shear, R1-shear, R2-shear, P-shear as well as tension fracture, bookshelf glided structure and so on. These microstructures are commonly recognized as the product of seismic fault slipping. Furthermore, within the area between two parallel Y-shears of the fault gouge, a few of microstructures of distributed ductile deformations were developed, such as P-foliation, elongation and asymmetrical trailing structure of detrital particles. The microstructure features of fault gouges implicate the thrust movement of the fault during the Wenchuan earthquake. In addition, the fault gouge has less quartz and feldspar and more clay than the surrounding rocks, which indicates that some quartz and feldspar in the surrounding rocks were transformed into clay, whereas the fault gouge has more illite and less illite/montmorillonite mixed layers than the surrounding rocks, which shows that the illite/montmorillonite mixed layer was partly converted into illite due to temperature increasing induced by coseismic fault slipping friction (also being affected partly by the chemical action of solutions). Such microstructures features and mineral component changes recorded the information of fault slip and provide criterions for discussing the genesis of fault gouge and recognition of the direction of fault movement. © 2015, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84931560694&doi=10.1007%2fs00531-015-1160-8&partnerID=40&md5=678edf722f4843391136e0bc6ef78171
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70287
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Key Laboratory of Active Tectonics and Volcano, Institute of Geology, China Earthquake Administration, A1#, Huayanli, Chaoyang District, Beijing, China
Recommended Citation:
Yuan R.-M.,Zhang B.-L.,Xu X.-W.,et al. Microstructural and mineral analysis on the fault gouge in the coseismic shear zone of the 2008 Mw 7.9 Wenchuan earthquake[J]. International Journal of Earth Sciences,2015-01-01,104(5)