Reviews — Geology of Alaska. 31 



2. Geology of Alaska. — "We have received six bulletins relating to 

 this territory, all published in 1913. No. 526 is on the "Coastal 

 Glaciers of Prince William Sound and Kenai Peninsula ", by 

 Messrs. U. S. Grant and D. F. Higgins. This is well illustrated 

 by maps and pictorial views, and " is intended to supply some 

 definite information regarding the present positions and fronts of 

 the glaciers, and the more evident facts of their fluctuations", 

 with the desire also of attracting attention " to some of the most 

 magnificent American scenery that is now accessible to the tourist 

 and nature lover ". 



Five other bulletins contain descriptions of the geology, and 

 especially of the placer deposits, of various parts of Alaska, and 

 they will be invaluable as guides to prospectors and to further mining 

 enterprises. No. 532, on "The Koyukuk-Chandalar llegion ", bj' 

 Mr. A. G. Maddren, deals with a portion of the Yukon river-flats 

 and of its tributary the Koyukuk. No. 533 is on the "Geology 

 of the Nome and Grand Central Quadrangles", by Mr. F. H. Moffit, 

 who describes an area in the southern part of the Seward Peninsula. 

 It is remarked that " Bonanza mining in the Nome region, which 

 has produced over $50,000,000 worth of gold, is now nearly a thing 

 of the past", but the record is " of one of the richest placer camps 

 of Alaska ". Nevertheless the prospects of further profit are by 

 no means discouraging; there are still "large bodies of auriferous 

 gravels, many of which can be profitably exploited", while "the 

 field is well worthy of careful prospecting for vein deposits "j 

 Although gold only has been mined with profit, small quantities of 

 lode and placer tin have been obtained, and the occurrence also is 

 noted of silver, lead, tin, bismuth, antimonj', tungsten, copper, and 

 mercury, in bed-rock and gravel deposits. No. 535 contains " A 

 Geologic lleconnaissance of a Part of the Rampart Quadrangle ", 

 by Mr. Henry M. Eakin. This area lies along ihe Yukon Eiver above 

 Tanana town, and extends to the tributary valley of the Tanana 

 Kiver at Hot Springs. Gold occurs in the modern stream deposits 

 and in the older terrace or bench gravels, but no other mineral 

 has proved to be of economic importance. No. 525 is a "Geologic 

 Reconnaissance of the Fairbanks Quadrangle ", by Mr. L. M. 

 Prindle, with assistance from Mr. F. J. Katz and Mr. Philip S. 

 Smith, and is the most elaborate of the reports before us. The 

 area adjoins that of the Rampart Quadrangle, extending higher 

 along the course of the Tanana River. The report indicates that the 

 placer- gold reserves are still very large, but that a great expansion 

 of the industry in this field " can be brought about only by lessening 

 the operating costs through improved means of communication". 

 There are favourable prospects also for lode-mining, though at 

 present the alluvial deposits have furnished practically all the gold. 

 " Silver occurs as an impurity in the placer gold." It is remarked 

 that most of the alluvial deposits are frozen throughout the year. 

 No. 534 contains an account of " The Yenta District ", by Mr. Stephen 

 R. Capps. The Yenta River is a tributary of the Susitna, which 

 flows into Cook Inlet on the southern, side of Alaska. The Alaska 

 Mountains lie to the north-west, and it is remarked that "the 



