We investigated the relationship between contractional deformation of sedimentary mass in the upper crust and the geodetic strain rate in a high-strain zone (part of the Niigata–Kobe Tectonic Zone) of the mid-Niigata region, Central Japan. We observed numerous examples of layer-parallel slip (bedding-plane slip) generated by folding. The slip layers have an average spacing of ~ 3.6 m (measured normal to bedding planes) at the Katagai site. In shallow sedimentary units of the upper crust, numerous bedding-plane slip events act to reduce the mechanical strength (effective elastic thickness) of sedimentary rocks under contractional deformation. The results support an existing model, based on geodetic observations, of mechanical decoupling between the weak sedimentary layers and basement. On the layer-parallel slip, we measured the friction coefficient of gouge generated by bedding-plane slip and of mud around non-slip surfaces using double-direct shear tests, and found no difference in frictional coefficient between slip and non-slip surfaces.

中文翻译：

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日本新泻地区高应变带层平行滑移控制的浅层上地壳的非弹性行为和机械强度

我们研究了上地壳沉积物收缩变形与日本中部新泻中部地区高应变带（新泻-神户构造带的一部分）的大地应变率之间的关系。我们观察到许多由折叠产生的层平行滑动（层理平面滑动）的例子。在 Katagai 场地，滑动层的平均间距约为 3.6 m（垂直于层理平面测量）。在上地壳的浅层沉积单元中，许多层理面滑动事件在收缩变形下降低了沉积岩的机械强度（有效弹性厚度）。结果支持现有的基于大地测量观测的弱沉积层和基底之间机械解耦模型。在平行层滑移​​上，