Tectonic Geography of Eastern Asia. — H'obbs. 215 
chains of islands festooned along the coast, of Avliich the more 
important are the Japanese chain, h^ormosa, the Philippines, 
and the Malaysian archipelagd. 
Both by reason of its political importance and of its de- 
tailed geological exploitation, Japan is deserving of the first 
consideration. The excellent groundwork laid by Edmund 
Naumann* and Teyokitsi Haradaf have been utilized by pro- 
fessor Suessj:, by members of the staff of the Imperial (Geo- 
logical Survey. § and especially by Baron von RiclUhufen in 
the latest of his papers||. This la:tter paper for the first time 
makes available for the use of geologists a comprehensive 
phvsiographic and geologic structural study of the country as 
a whole. Its importance warrants its complete translation into 
English. 
Edmund Xaumann fixed a boundary line, his fossa magna, 
bv which he separated north and south Japan. This boundary 
line runs in a NXW-SSE direction through the middle of the 
main island of Japan near its bend or "elbow." This well 
recognized tectonic line figures in all later geological studies 
of the empire. Through north Japan, lying to the east of the 
tectonic line, runs Naumann's meridional chain carrying a 
great number of active and extinct volcanoes. Koto had 
already given the name Sachalin system to this median line 
because the range of volcanoes maintains the same direction as 
the island of Sachalin further to the north. The physiographic 
divisions of Japan are thus concisely stated by Kotolf. 
A mere glance at the topographic map of Japan will lead one to 
suppose that Hon-shu is a gigantic arc with Hokkaido and Kiu-shu at 
the north and south ends as the homologous appendages ; and the line 
of the Fuji-Ogasawara volcanoes pierces right through the middle of 
main island. But, as geological knowledge accumulates little by little 
• Edmund Naumann. Ueber den Bau und die Entstehnng der japanischen 
Inseln. Berlin, 1885, p. 91. 
t Tbvokit.«i Harada. Versuch einer tektonischcn Giiederung der japanisch- 
en Inseln. Tokyo, 1888, p. 23 and map. 
X Edcard SiiESs. Das Antlitz der Erde .Vol. ii, 1888, pp. 220-227; vol. iii, 
1901, pp. 176-186. 
§ Ontlines of the Geology of Japan. DescriptiTC text to accompany the 
geological map of the Empire on the scale of 1 : 1,000,000. compiled by the 
officials of the Imperial Geological Snrvcy of Japan. Tokyo. 1902. 
1! Fkriii.nand v. Richthofhn. Geomorphologische Studien aus Ostasien. 
V. Gebirgskettunpen im japanischen Bogen. Sitzungsber. d. k. p. Akad. d. 
Wissenseh. Berlin, vols, xxxviii-xl. 1903. pp. 892-91 2. 
TB. Koto. The scope of the Viilcanological Survey of Japan. Publication 
No. .3 of. the Earthquake Investigation Committee in Foreign Language!. 
Tokyo, 1900, p. 15. 
