242 Tlie American Geologist. April, i89o 
ces of these local glaciers are left in small terminal moraines blocking 
the valleys. 
On the alluvial plains to the east the beaches of lake Agassiz are 
traced northward as far as the Swan river valley in Lat. 52°, w^here 
they appear to still retain the same well marked characters of those 
further south in Minnesota and Dakota. The north end of lake Agas- 
siz has not yet been reached. Its shore lines ascend northward at the 
rate of a foot or more per mile, the highest observed beach (near lat. 
51° 50') being at an elevation exceeding 1,400 feet above the sea, or 
700 feet above lake Winnipeg. White or cream-colored Devonian 
limestones underlie the Cretaceous series, and are the bed-rock of the 
country east of the mountain escarpment. 
The map is the first Canadian contour map that we have seen cover- 
ing any extensive area, and serves very well to illustrate the varying 
slopes of the country and the position and extent of the gravel ridges. 
Dr. Andrew C. Lawson's Report on the geology of the Rainy Lake 
region, which completes Part I of this volume, has been reviewed in 
the American Geologist, January, 1890. 
In Part II, Mr. E. D. Ingall, mining engineer, is author of a Report 
on mines and mining on lake Superior, 131 pages, with thirteen plates 
and two maps. The district reported is the silver-bearing one on the 
north side of lake Superior between Black bay and Pigeon river. The 
silver ores are the native metal and sulphide or argentite generally 
associated with blende, galena, pyrites, etc., in a gangue of calcite, 
barite, quartz, and fluorite, in a series of fissure veins traversing the 
nearly horizontal Animikie formation. Black, soft, carbonaceous 
argillites constitute the upper part of this formation ; while the chief 
character of its lower part consists in "the almost entii'e preponderance 
of siliceous rocks, such as chert and jasper, which are often accom- 
panied by ferruginous dolomites, and themselves all contain more or 
less iron in the oxidized state, at some places carrying so much mag- 
netite as to constitute almost an iron ore." All the bodies of silver ore, 
so far as known, occur near dykes or sheets of trap rock, and Mr. 
Ingall concludes that "the silver may be derived from them by decom- 
position of some of their mineral constituents carrying minute quanti- 
ties of silver, by waters infiltrating downwards through all their joints 
and pores, and that these waters passing onwards and soaking into 
the permeable parts and minerals of the gangue in the veins, have 
there deposited their silver contents, the various forms of carbon pres- 
ent in the sedimentary rocks having had some influence in eflfecting 
precipitation." 
Mr A. P. Low presents a Report on explorations in James' Bay and 
country east of Hudson Bay, drained by the Big, Great Whale, and 
Clearwater rivers, 94 pages, with three plates. His observations of 
glacial strife and transportation of boulders accord with those of Dr. 
Robert Bell, showing that the continental ice-sheet had a motion from 
northeast to southwest and west across James' bay and onward over 
