Lithification facilitates frictional instability in argillaceous subduction zone sediments
Lithification facilitates frictional instability in argillaceous subduction zone sediments
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岩化促进了泥质俯冲带沉积物的摩擦不稳定
DOI：
10.1016/j.tecto.2015.10.004
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发表时间：
2015
期刊：
影响因子：
2.9
通讯作者：
A.J. Kopf
中科院分区：
文献类型：
--
作者：
Trütner;Hüpers;A.J. Kopf
先前的研究表明，在俯冲带，> ~ 5-10 km 深度的大地震成核的发生可能是由与岩化过程相关的多种因素共同驱动的。在这些深度，岩化过程通过改变板块边界断层带和围岩的力学性质来影响整个断层系统。为了检验俯冲带沉积物的岩化作用产生能够通过成岩作用和低级变质作用进行地震成核的岩石的假设，我们对从日本西南部四万十带暴露中回收的俯冲带化石化石进行了摩擦实验。这些变沉积物代表了经历了 125 至 225 °C 最高温度的增生和俯冲物质，代表了四万十带前陆活跃的南海俯冲巨型逆冲断层沿线的地震深度。我们发现完整的四万十岩石样本保留了成岩和变质过程的影响，在原位压力条件下表现出不稳定滑移的潜力。在相同条件下测试的相同样品的粉末版本仅表现出速度增强的摩擦，从而证明破坏岩化状态也消除了不稳定滑移的可能性。使用先进的孔隙度损失来量化岩化过程，我们证明了速度减弱的增加与日益先进的岩化有关。结合已记录的浅层俯冲带沉积物的摩擦稳定行为，我们的结果提供了证据，证明沉积物岩化假说可以解释沿俯冲带巨型逆冲断层的大地震成核的深度依赖性爆发。
Previous work suggests that in subduction zones, the onset of large earthquake nucleation at depths > ~ 5–10 km is likely driven by a combination of factors associated with the process of lithification. At these depths, lithification processes affect the entire fault system by modifying the mechanical properties of both the plate boundary fault zone and the wall-rock. To test the hypothesis that lithification of subduction zone sediments produces rocks capable of earthquake nucleation via diagenesis and low-grade metamorphism, we conducted friction experiments on fossil subduction zone sediments recovered from exposures in the Shimanto Belt in SW Japan. These meta-sediments represent accreted and subducted material which has experienced maximum temperatures of 125 to 225 °C, which are representative of seismogenic depths along the active Nankai subduction megathrust in the foreland of the Shimanto Belt. We find that intact Shimanto rock samples, which preserve the influence of diagenetic and metamorphic processes, exhibit the potential for unstable slip under in-situ pressure conditions. Powdered versions of the same samples tested under the same conditions exhibit only velocity-strengthening friction, thus demonstrating that destroying the lithification state also removes the potential for unstable slip. Using advanced porosity loss to quantify the lithification process, we demonstrate that increased velocity weakening correlates with increasingly advanced lithification. In combination with documented frictionally stable behavior of subduction zone sediments from shallower depths, our results provide evidence that the sediment lithification hypothesis can explain the depth-dependent onset of large earthquake nucleation along subduction zone megathrusts.
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影响因子：
3.1
作者：
K. Ujiie;H. Yamaguchi;A. Sakaguchi;S. Toh
通讯作者：
K. Ujiie;H. Yamaguchi;A. Sakaguchi;S. Toh
日本四国第三纪四万十带成岩作用和低温变质作用的有机和无机指标的比较
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
M. Underwood;M. Laughland;S. M. Kang
通讯作者：
S. M. Kang
日本四国室户半岛第三纪四万十带的热演化
DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
M. Underwood;M. Laughland;T. Byrne;J. Hibbard;Lee DiTullio
通讯作者：
Lee DiTullio
增生棱镜如何阐明俯冲带的地震成因
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
J. Moore;R. Christie;Meneghini Francesca
通讯作者：
Meneghini Francesca
影响因子：
3.9
作者：
K. Ujiie;G. Kimura
通讯作者：
K. Ujiie;G. Kimura