THE GREAT EKUPTION OF SAKURA-JIMA IN 1914. 



51 



by loose sandy tuffite (ß) — ii coiiiplex wliicli remlncW^ ns of Hie Diluvial 

 lapilli bed of ihc. Kwjosliima environs (Text-fig. 3, ]>. 14). A slightly 

 sjiliue Avater seeps out fi'oin the jnnction of the two beds on the south shore, 

 which induced five families from Akamizu of Sakura-jima to settle here 

 twenty years after its formation. A ])umiceous gray lava-How covers 



Fig. 13.— Three new islands, Shin-jima, IwO-jimfi, luid \"('l)isn-jiiiia, nt 17v!i Jv.so. 



(After YiimiigTicbi.) 



l)oth edges of the central low stretch, which seems to the writer to be a 

 ruined crater-bottom of a submarine vent. Tlie cliffs which bound the 

 island are solely due to marine abrasion. On August 9, 1786, a storm 

 swept away the south-eastern headland leaving a shallow wliich was once 

 occupied by hind. 



1) K. Yamagtjchi {loc. cit., footnote p. 49) is inclined to believe the island of Shin-jima to 

 1)6 of an old date in spite of frequent citations about its new creation during the An-ei erup- 

 tions in the literature of that ]ieriod. 



Sandy tiiffite and lapilli lieds, which Yajiaguchi mentioned, build up a large portion of the 

 iîslaud, and closely resemble the Diluvial Plateau Formation of Kagoshima ; but if these beds are 

 really identical with the latter, then the island must be considered to be a detached geologic block 

 of the Plateau Formation, similar to ()ki-Kojima and four other islands briefly outlined (p. 23-30). 

 The writer, however, found no crystals of hornblende or biotite in shore sand in his collection, 

 which are important constituents of the basal andésite from which the old tuffite and lapilli beds 

 are derived elsewhere, iloreover, the pumiceous andésite, which intrudes and partially covers 

 the underlying sedimentaries, is of the same Idnd as that of the An-ei lava — a fact indicating 

 close genetic relation with the neighboring islets raised during the An-ei eruption. 



A remarkable fact discovered by Yamaguchi, is, however, the jiresence of moUuscan shells 

 and diatoms entombed in the surface soil, 44 m. high, which, according to his interpretati(m, 

 are not of recent origin. 



In short, the question as t(j the origin of Shin-jima awaits further researches. 



