Reviews — Geological Survey of Canada. 23^5 



DR lEJ "V IIE "W S. 



I. — GEOLoaiCAL Survey of Canada. By Egbert Bell, M,D., 

 F.R.S., etc., Acting Director. Report on the Klondike Gold- 

 fields. By R. G. McConnell, B.A. Part B of Annual Report, 

 vol. xiv. 8vo. Ottawa, 1905. 



rriHIS report is based on field-work carried on during the season 

 JL of 1903, and completes a preliminary report published in 1900. 



The existence of gold on the Yukon has been known since 1869, 

 first in Alaskan, afterwards in Canadian territory. The Klondike 

 district came into notice in connection with gold-raining in the year 

 1894. The goldfields have an area of about 800 square miles, and 

 are situated east of the Yukon River in latitude 60° North. Th© 

 streams flowing through the area are all gold-bearing to some 

 extent, but only a limited number have proved remunerative. The 

 Klondike and Indian Rivers, bordering the district on the north and 

 south respectively, are comparatively small streams ; both drain 

 into the Yukon. The smaller streams and creeks draining the 

 interior of the district are the sources of the gold. 



The geological features of the country may be summarized as 

 follows : — The rocks have a wide range in age, and present great 

 variations in structure and composition, owing to igneous intrusions 

 at different periods and enormous pressure from earth-movements. 

 The oldest and most important formations consist of ancient schists, 

 partly of clastic, partly of igneous origin. 



The schists are divided into three series, viz., the Nasina Series- 

 (clastic), the Klondike Series, and the Moosehide Series (diabase). 

 The unaltered sedimentary rocks belong to Early Tertiary (Renai ?) 

 and Late Tertiary (Flat-creek Beds). The massive igneous rocks- 

 comprise granite, diabase, andesites, quartz porphyries, and serpentine. 

 These rocks are fully described in the report. 



A description of the gold-producing creeks with illustrative 

 sections is given, showing the position of the auriferous gravels and 

 their relations to the underlying ' Klondike schists.' The methods 

 used for extracting the gold are either by sinking and drifting or by 

 open-cut work. The gravels, being everywhere frozen, require to be 

 thawed before they can be extracted, and this is done, except in 

 remote districts, by means of steam thawers or by pumps. The 

 gold production of the Yukon territory since the discovery of the 

 Klondike goldfields in 1896 is estimated by the Geological Survey 

 at over 96,000,000 dollars (1896-1903). Nearly the whole of this 

 immense amount was obtained from the various Klondike creeks 

 and benches.^ It is stated that ' placer ' mining will undoubtedly 

 be supplemented, sooner or later, by hydraulic mining on a large 

 scale. 



This report is well illustrated with views of the workings and 

 with two maps of the Klondike mining district on a scale of twa 

 statute miles to one inch. A. H. F. 



1 Benches represent fragments of older valley-bottoms partially destroyed by the 

 excaYation of the present valleys. 



