Generation of amorphous carbon and crystallographic texture during low-temperature subseismic slip in calcite fault gouge
Generation of amorphous carbon and crystallographic texture during low-temperature subseismic slip in calcite fault gouge
复制标题
方解石断层泥低温次震滑移过程中无定形碳的生成和晶体结构
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
M. Verrall
中科院分区：
文献类型：
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作者：
C. D. Piane;S. Piazolo;N. Timms;V. Luzin;M. Saunders;J. Bourdet;A. Giwelli;M. Clennell;C. Kong;W. Rickard;M. Verrall
Identification of the nano-scale to micro-scale mechanochemical processes occurring during fault slip is of fundamental importance to understand earthquake nucleation and propagation. Here we explore the micromechanical processes occurring during fault nucleation and slip at subseismic rates (∼3 × 10−6 m s–1) in carbonate rocks. We experimentally sheared calcite-rich travertine blocks at simulated upper crustal conditions, producing a nano-grained fault gouge. Strain in the gouge is accommodated by cataclastic comminution of calcite grains and concurrent crystal-plastic deformation through twinning and dislocation glide, producing a crystallographic preferred orientation (CPO). Continued wear of fine-grained gouge particles results in the mechanical decomposition of calcite and production of amorphous carbon. We show that CPO and the production of amorphous carbon, previously attributed to frictional heating and weakening during seismic slip, can be produced at low temperature during stable slip at subseismic rates without slip weakening.
