The Geology of the Southern part of Kanto plain, especially Tokyo and its environs was known as the. strata of the Alluvium, the Diluvium, which was composed of loam, the Narita and Tokyo Series, old Diluvium, and Tertiary. They were dislocated by the normal faults of Yamate, NNE-SSW, and Oji-Akabane, NW-SE, where on the west side it was left as fluff covered by loam, while on the east side the loam was eroded off by sea wave, and Alluvium was deposited on the series of Narita and Tokyo.
I have accidentally discovered a thrust, trending N 37° E, NW 23°, of the series of Narita and Tokyo under the loam, at the Kanda Shrine, by a special Core-borer. Soon thereafter I have detected another, indicating N 87° E, S 2°30', at th seat of Tokyo University.
Successively I have found a lot of thrusts in the underground on the area, which were arranged in four zones, grouping two kinds of the strikes, NE-SW and NW-SE, side by side, also showing undurations in each zone.
The investigation was executed by using the Nishio Core-boring Machine (J. P., A. P. and B. P.), taking samples of geology as core, with the least shrinkage, and measuring simultaneously the resistance of strata during sinking bore-hole.
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