554 J. G. H. GODFKEY ON THE GEOLOGY OE JAPAN. 



iron-ore, and sphaerosiderite, are also found in Japan, but only in 

 such limited quantities as to be of little interest as regards their 

 economical value. Clay iron- ore is of the most common occurrence 

 amongst the ores just mentioned ; but owing to its more difficult 

 treatment it has not yet been used in the manufacture of iron. 



Large deposits of massive iron-pyrites are found in various locali- 

 ties. One of the most important is that occuring at Tashino (prov. 

 Mimasaka). A lode from 3 to 8 feet wide, bearing from E. to "W. 

 and dipping 66° to the S., is found there in a met amorphic talcose 

 slate, and consists of a massive iron-pyrites containing some copper- 

 pyrites. As a rule the contents of copper increase when the lode 

 becomes narrower. The ore raised is used for the manufacture of 

 sulphate of iron. 



(/) Petroleum. — The provinces best known as regards the occur- 

 rence of petroleum are Shinano and Echigo, of which a geological 

 survey was begun in 1876 by B. S. Lyman ; and in the following 

 statement I shall avail myself of the published results of the first 

 year's work*. 



The petroleum is found either in yellowish-brown and grey sand- 

 rocks, or in a dark volcanic breccia and a dark grey, slightly oily 

 shale. The formation of the petroleum must be regarded as con- 

 temporaneous with the deposition of the volcanic breccia. 



There are numerous traces of petroleum and gas in these two pro- 

 vinces. In Shinano there exist 22 productive wells, of which the 

 deepest is 57 fathoms deep, and the best has a yield of 2\ barrels per 

 day. The total yield, however, of all these 22 wells is somewhat above 

 five barrels per day, or in a year less than 1900 barrels. In Echigo, 

 522 productive wells are known, of which the deepest is 122 fathoms 

 deep, and the greatest yield of one 1*2 barrel per day. The total 

 yields amount to 26 barrels per day, or, assuming the same pro- 

 duction for all the year round, 9500 barrels per year. 



(g) Lead. — Lead-ores are only poorly represented amongst the 

 minerals found in Japan. They occur at Tai'ra (prov. Ugo), Hoso- 

 kura (prov. Eikuzen), and Hakoosan (prov. Eikuchu). As regards 

 the occurrence at Tai'ra, I am not in a position to furnish any de- 

 tails. 



At Hosokura the lode occurs in a granite, and has a bearing from 

 N.E. to S.W., and a very variable north-westerly dip. Its average 

 thickness amounts to 4 feet, and the veinstuff is composed of galena, 

 blende, quartz, and decomposed granite. The outcrop of this lode 

 has been traced for a distance of more than a mile. 



The lode at Hakoosan is of a similar composition, but has an 

 average width of only 1 foot, and runs from S.E. to N.W., with a 

 south-westerly dip in a felspathic porphyry (rhyolite). The total 

 production of lead in Japan, per annum, was estimated by me 

 in 1874 at 185 tons. 



(h) Tin. — Tin-ore occurs only in small quantities. In the pro- 



* Geological Surrey of the Oil-lands. Report of Progress for the first Year. 

 By B. S. Lyman. Tokio, 1877. 



