Fault gouge : rock magnetic and structural study

为了从岩石磁学的角度获得断层泥的新信息，我们进行了一系列的实验。结果如下：1)安装了GISCO的kappbridge KLY-3S，并对其可靠性进行了精确测试。我们发现Pj（各向异性度）和T（形状参数）都可以用来参数化磁化率的各向异性。2)我们在活动的Sanageyama-kita断层（濑户市）取样断层泥。断裂面附近的样品显示AMS的铅笔状结构。最大轴与断平面走向平行，最小轴呈带状分布。除断裂面外，其余样品呈有序的沉积披萨状。最大轴似乎被限制在断层面上，这将进一步约束断层的运动方式。3)我们还从宽断层泥出现的Kabuto-gawa断层（Suzuka-gun）收集了样本。样品的AMS完全呈扁圆形。扁岩面既不与断裂面平行，也不与沉积面平行。

We conducted series of experiment to obtain new information from fault gouge from view point of rock magnetism. The results ara follows :1) We have installed GISCO's Kappabridge KLY-3S and tested its reliability precisely. We found Pj (degree of anisotropy) and T (shape parameter) are both useful in parameterizing anisotropy of magnetic susceptibility (AMS).2) We sampled fault gouge at the active Sanageyama-kita Fault (Seto City). Samples from the close vicinity of the fault plane show pencil structure of AMS.The maximum axis is parallel with the strike of fault plane, whereas the minimum axis distributes as girdle. The other samples collected apart from the fault plane show ordinal sedimentary pizza shape. The maximum axis seems to be confined on the fault plane, whichi will give further constraints about the mode of movement of the fault.3) We also collected samples from the Kabuto-gawa Fault (Suzuka-gun) where wide fault gouge cropped out. AMS of the samples show oblate shape exclusively. The plane of oblate is neither parallel with the fault plane nor with sedimentary plane.