Lithologic control of frictional strength variations in subduction zone sediment inputs
Lithologic control of frictional strength variations in subduction zone sediment inputs
复制标题
俯冲带沉积物输入中摩擦强度变化的岩性控制
作者：
M. Ikari;A. Kopf;A. Hüpers;C. Vogt
在会聚边缘，海洋沉积物沉积的俯冲带弧前的传入板块（“俯冲输入”）代表的初始条件，在俯冲过程中的地质力学过程。这些沉积物的摩擦强度是控制俯冲过程中变形的关键参数，其一级受控于岩性成分。我们在这里结合联合收割机的实验室摩擦实验的结果和定量的矿物组合的科学钻探样品恢复从三个特别良好的研究俯冲带：南海海槽（日本西南部），日本海沟（日本东北部），和哥斯达黎加。在日本海沟，弱的富含蒙皂石的远洋粘土与较强的硅质半远洋材料形成鲜明对比。这种强度对比决定了初始板块边界形成的地层位置，并影响了浅层巨型逆冲断层的滑动行为。在哥斯达黎加的俯冲带，相对较弱的富含粘土的半远洋沉积物覆盖在较强的远洋超微化石软泥和白垩上，这可能是特征发展的一个因素，如脚趾附近的少量碎屑和以软泥或白垩为主的俯冲侵蚀。然而，在南海海槽中，观察到了与粘土矿物含量无关的大范围摩擦强度值。在这种情况下，南海的力学行为可能受到与成岩作用或流体超压有关的其他因素的影响。
At convergent margins, marine sediments deposited seaward of the subduction zone forearc on the incoming plate (the “subduction inputs”) represent the initial condition for geomechanical processes during subduction. The frictional strength of these sediments is a key parameter governing deformation during subduction, which is controlled to first order by lithologic composition. We combine here the results of laboratory friction experiments and quantification of mineral assemblage for scientific drilling samples recovered from three particularly well-studied subduction zones: the Nankai Trough (southwestern Japan), the Japan Trench (northeastern Japan), and Costa Rica. In the Japan Trench, frictionally weak smectite-rich pelagic clay contrasts sharply with stronger, more siliceous hemipelagic material. This strength contrast dictates the stratigraphic position of initial plate boundary formation and influences slip behavior of the shallow megathrust. In the Costa Rica subduction zone, relatively weak clay-rich hemipelagic sediment overlies frictionally strong pelagic nannofossil oozes and chalks, which could be a factor for the development of features such as a small amount of offscraping near the toe and subduction erosion where ooze or chalk dominates. In the Nankai Trough, however, a wide range of frictional strength values is observed that does not correlate with clay mineral content. In this case, mechanical behavior at Nankai is likely influenced by other factors related to diagenesis or fluid overpressuring.
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影响因子：
3.7
作者：
M. Stipp;Malte Rolfs;Y. Kitamura;J. Behrmann;K. Schumann;D. Schulte‐Kortnack;V. Feeser
通讯作者：
M. Stipp;Malte Rolfs;Y. Kitamura;J. Behrmann;K. Schumann;D. Schulte‐Kortnack;V. Feeser
数据报告：来自 IODP Expedition 343 (JFAST) 站点 C0019 的岩心样本的速率和状态相关摩擦参数
DOI：
10.2204/iodp.proc.343343t.203.2015
发表时间：
2015
期刊：
影响因子：
--
作者：
通讯作者：
--
改变海洋火山灰沉积物作为潜在的斜坡破坏面？
影响因子：
2.1
作者：
Wiemer
通讯作者：
Wiemer
弱俯冲碳酸盐岩中的地震成核
影响因子：
18.3
作者：
Kurzawski;Niemeijer;Spiers;Behrmann
通讯作者：
Behrmann
影响因子：
2.9
作者：
K. Schumann;M. Stipp;B. Leiss;J. Behrmann
通讯作者：
K. Schumann;M. Stipp;B. Leiss;J. Behrmann