富山県国見地区の地すべり粘土中の粘土鉱物について

抄録

X-ray diffracation method was used to determine the mineral composition of landslide clays and tuffaceous rocks collected in the Kunimi landslide area. Results showed that the landslide clays contained smectite, quartz, and feldspars, with analcime and illite in addition in some samples. Mineral composition of the tuffaceous rocks was very similar to that of the landslide clays, except that analcime was found often in the former.
The smectite content in the landslide clays and in the bottom face of the tuffaceous rocks (the upper face of hard mudstone rocks) increased along a traverse from the sliding head toward the tail, i. e, from high altitudes downwards indicating that the smectite in the landslide clays in the study area was formed from zeolites in the tuffaceous rocks, under the influence of groundwater flowing down along the sliding plane, which conformed with the upper surface of the relatively fresh bedrocks.