当前位置: X-MOL 学术J. Geophys. Res. Solid Earth › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Mixed‐Mode Formation of Amorphous Materials in the Creeping Zone of the Chihshang Fault, Taiwan, and Implications for Deformation Style
Journal of Geophysical Research: Solid Earth ( IF 3.9 ) Pub Date : 2020-05-22 , DOI: 10.1029/2020jb019862
Wen‐Jie Wu, Li‐Wei Kuo, Ching‐Shun Ku, Ching‐Yu Chiang, Hwo‐Shuenn Sheu, Tyas Dwi Aprilniadi, Jia‐Jyun Dong

Experimental results demonstrate that amorphous materials can be generated by frictional sliding at a wide range of conditions and that once formed the frictional strength of the fault is reduced. Nevertheless, amorphous materials have not been described in many natural faults, and their importance in natural systems is not well understood. We have identified amorphous materials within a 3‐mm‐thick slip zone (i.e., narrow band) in the Chihshang Fault, Taiwan, as well as within a submicrometer thick band in a distributed network of scaly clays. The scaly clays resemble those developed in other faults that demonstrably accommodated slow creep, and they also impart very low permeability implying that fluid‐related alteration (which could result in amorphization) will be inefficient. For this reason, and because of its throughgoing nature and position within a deforming zone, we infer a shear‐related origin for the amorphous materials. Therefore, amorphous materials can be observed in near‐surface environments because they have been formed during recent deformation under limited fluid‐circulation circumstances. The narrow slip zone containing amorphous materials is throughgoing and is interpreted to have acted as a frictional interface that accommodated brittle deformation at the macroscopic scale, whereas the surrounding mélange accommodated distributed “ductile” shear. The formation of amorphous materials therefore typifies the “mixed‐mode” style of deformation in this creeping fault zone.
更新日期:2020-05-22
down
wechat
bug