18 ART. 3. — B. KOÏÔ : 



the escarpment of dislocation on the left side. The region is likewise 

 built up of ash- stone C, or hypersthene-trachyandesite apparently 

 with some quartz, overlaid by block-mud B, and then lapilli 

 deposit A {see Fig. 3). The rolhng surface, 200 m, or more 

 high, built up of these rocks, descends abruptly eastward, as in 

 the figure, by faulting toward the lowland of Kaimon, on which 

 at later times the konide of the same name and the gigantic 

 crater-lake of Ikéda (PL IV. Fig, 2) with a diameter of 4 hn. 

 made their appearance, the one being the positive and the other 

 the negative form of nearly equal size and volume.^^ The re- 

 markably regular escarpment of over 100 ??î., so produced, runs 

 with a trend to N.N.E. as in the figure. It is a part of the cliffs 

 that bound the western shore of Kagoshima Bay. 



coxcLtTDiNo What has alreadv been stated will be sufficient 



xlEMAEKS ON '' 



M^noN^oF ^'^^ the present purpose in regard to the geology, and 

 Bay the way which led directly to the formation of Kago- 



shima Bay. The writer will now summarize the facts mentioned 

 and the suggestions made before. 



The bay is a slightly- bent trough at the south end of, geo- 

 logically speaking, the oblique horst of Kyûshù, and at its northern 

 blind recess rises the volcano island of Sakura-jima. The bay is 

 in average 20 km. wide, and 60 km. in its axial direction as the 

 prolongation of tlie volcano chain of Eyûkû. That it is a 

 topographic hollow was long since stated by v. Eichthofen and 

 SuESs, from tlie morphological aspect which it presents. Conscious 

 of this or not, our geologists hold the same view ; and especially 

 since the recent paroxysmal convulsion of Sakura-jima, the super- 



1) The diameters of the Lake Ikeda and the base of Kaimon are about 3.5 km., and the 

 volume of the lake also apiiroximately coincides with that of the volcano, being about 4 cub. Inn. 



