132 S. SEKIYA AND Y. KIKUCHI 



slopes of Kobandai are called, engulfed all the familiar land-marks, 

 and converted the district into a desert waste. Thousands of conical 

 mounds, large and small, have been formed on this vast sea of mud, — 

 giving a quite unique appearance. Not only have the depressions 

 been filled up, but the higher ridges have been reduced in height. 

 The deluge of earth débris in its quick descent, impinging on the pro- 

 minences that were lying in its way, have actually leaped over them, 

 scraping off the outer-crust of the soil, and exposing the native rocks 

 beneath, as a glacier might have done. In other places the torrent of 

 rocks dashed against the hill-sides and scoured them away. Large 

 quantities of mud carried along with rock, débris, and boulders, have 

 penetrated deep into every recess of the valley. The largest and 

 longest of the mud streams is that which flowed down the slope of 

 the river Nagase to the Kawakami spa. Near the village of Hibara, 

 and the former site of the little hamlet of Hosono, the peaty deposits 

 which had accumulated in the marshy ground have been ploughed 

 up. Large clumps of red loamy soil mixed up with half carbonized 

 wood and grasses are found turned up or standing in an irregular 

 state of contortion.* Nowhere could the scouring action of the mud 

 torrent be better realized than in these parts. 



The official reports relating to the area of land buried under mud 

 are given in the following figures. The loss of property involved is 

 said to have been immensely great. There is absolutely no hope 

 of recovering or reclaiming the buried land. 



* Among this turned up peaty deposit, an interesting occurrence of vivianite may here be 

 noticed. The formation of this mineral seems to have been brought about through the 

 agency of organic matter. It is found in the form of a beautiful azure-blue coloured, fine 

 powder, filling up the spaces especially of the rind and core of the fragmentary branches of 

 half carbonized wood belonging to some Coniferous tree. The spot, however, where we have 

 witnessed this phenomenon, being situated just on the sourthern front of Hibara lake, must 

 have now been submerged under water. 



