REVIEWS 95 
age of the latter is inconclusive as it rests on the fact that they cut 
Triassic sandstones. On this evidence they might be post-Triassic. 
The region comprises a series of folds, beveled to the present surface, 
and one great overthrust fault. The jointing, folding, faulting, and 
schistosity are referred to the same epoch of compression. 
Four types of ore bodies are noted, namely impregnations in the 
schists, stringer leads in quartz, parallel to the schistosity, quartz veins 
cutting the schistosity, and replacement deposits. 
The ore minerals are auriferous pyrite, chalcopyrite, galena, and zinc 
blend. The deposits are referred to magmatic waters, perhaps emanating 
from a granitic mass a few miles west. The time of deposition is placed 
after metamorphism. In view of Emmons’ recent work in Maine and 
Tennessee the evidence on this last point needs to be more carefully 
worked out. 
A. D. B. 
The Iron Ore Supply of Japan. By Kinosuxe INouve. “The 
Iron Ore Resources of the World.” Stockholm, 1910. Pp. 
927-69; Plates 4; Figs. 13. 
The iron ore deposits of Japan are classified in six groups as follows: 
I. Magmatic segregations in granite. Not of economic importance 
under present conditions. 
II. Bedded deposits usually in connection with radiolarian quartz- 
ites and slates of Paleozoic and Mesozoic age. The ores carry from 20 
to 50 per cent iron with silica up to 40 per cent. They are usually rather 
high in phosphorus. 
III. Contact deposits in limestone near contact with intrusives. 
These are the most important ores of Japan. The ore is chiefly magnetite 
with minor amounts of micaceous hematite and limonite. The iron 
content averages from 55 to 60 per cent with some analyses giving over 
69 per cent. The ores are mixed with contact minerals and quartz and 
in some cases contain pyrite and chalcopyrite. 
IV. Veins in various kinds of rocks. Not of great importance under 
present conditions. 
V. Limonite deposits derived from the decomposition and redeposi- 
tion of pyrite or magnetite deposits or by deposition from ferruginous 
springs. These are next in importance to class III. 
VI. Alluvial deposits of iron sand derived from the decomposition 
of older rocks. 
The amount of ore in sight is estimated at 19,000,000 metric tons; 
