422 REVIEWS 



Vaux, George, and William, S., Jr. Observations Made in igoo on 

 Glaciers in British Coluitibia. Proc. Phil. Acad. Nat. Sci., for 1901, pp. 

 213-15. 

 Notes on the movements of the glaciers are presented. 



ALASKA. 



Brooks, A. H., and Collier, A. J. Glacial Phenomena of the Seward 

 Penitisula. Abstract, Science, N. S., Vol. XIII, 1901, pp. 188, 189. 



No evidence of general glaciation v^'as found, but there were centers of local 

 glaciation. The valleys of the Kiglovs^-aik range are glaciated to 500 feet above the 

 valley floors, and the moraines were deposited close to tide water. Shrunken rem- 

 nants of some of the glaciers still persist, and are, so far as known, the most northerly 

 in Alaska, being in latitude 65°. There is evidence of a recent elevation of 600 to 

 800 feet, but it antedates the maximum extension of the glaciers. 



Brooks, A. H. Sketch of the Geology of Southeastern Alaska. Profes- 

 sional Paper No. i, U. S. Geol. Surv., pp. 31-3, 1902. 



Existing glaciers are found chiefly on the Pacific mountain system, and the largest 

 development is on the seaward slope. On the Pacific side of the St. Elias range the 

 perpetual snow limit is alsout 2,000 feet, and on the inland slope about 6,500 feet. 

 The glaciers on the Pacific slope are much larger than on the inland slope. The 

 Coast Range has less conspicuous glaciers than the St. Elias, and they are mainly on 

 the seaward slope. 



The extent of former glaciation was much greater than at present, though its 

 limits were .fully determined at but few points. It is not known whether the higher 

 mountains were covered. On Prince of Wales Island glacial action was found up to 

 2,200 feet, but near Niblack Anchorage it seems to have reached no higher than 2,000 

 feet. In general the Alexander Archipelago was glaciated up to at least 2,000 feet. 

 Farther north glaciation reached higher altitudes, there being glacial bowlders near 

 Juneau at 3,200 feet, and this town stands on a moraine. Terraces along the valley 

 walls of Chilcat and one of its tributaries are thought to have been built while the 

 valley was still occupied by glacier ice. Rock-cut basins occupied by lakes are not 

 uncommon, especially in the Ketchikan region. On Prince of Wales Island is a lake 

 basin a mile long and a quarter of a mile broad entirely surrounded by a rock rim. 



Brooks, A. H., Richardson, G. B., Collier, A. J., and Mendenhall, 

 W. C. Reconnaissances in the Cape Nome and Norton Bay RegioiiSy 

 Alaska, in igoo. House Doc, No. 547, 56th Cong., 2d Sess., 222 

 pages, 1 90 1. 



The surface geology is briefly discussed on pp. 41-7 under the topics : river and 

 stream gravels, beach deposits, terrace deposits, glacial deposits, extra-morainic drift, 

 ground ice, and soil. No evidence of regional glaciation was found, but four local 

 centers of glacial action are reported. Of these the most important is in the Kiglu-aik 

 mountains. There the valley slopes are glaciated up to an elevation 500 to 600 feet 

 and head in glacial cirques, while at the margin typical moraines were found. Rem- 

 nants of glaciers still persist in the higher mountain valleys. The extra-morainic drift 

 found in the vicinity of Nome reaches an altitude of 800 feet. It is not necessarily 



