178 Reviews — Geological Survey of Canada. 



wonderful resourcefulness and the scientific attainments so happily 

 blended in the Canadian geologist. 



The Summary Eeport (A) by the Director, Dr. G. M. Dawson, 

 dated January, 1898, contains a brief record of the executive and 

 office work of the department and of the organization and main 

 results of the field-work up to the end of the year 1897. The 

 reports which follow have, as usual, all been issued separately, prior 

 to the completion of the general report. 



The Director i-efers especially in his report to the rich discoveries 

 of placer gold on the Klondike and its tributary streams in the 

 Yukon District, verifying his forecast as to their great value 

 published in 1889. More detailed geological investigations must 

 be made before the question of the origin of the gold can be solved. 

 A prolonged and uninterrupted wearing down, from a very early 

 period in the Tertiary, of rocks containing auriferous veins may, 

 in part, account for the great quantities of residuary gold now 

 contained in the placers. 



The operations of the field parties (to the number of fifteen) 

 embraced the following widely extended regions, viz., British 

 Columbia (2), North- West Territories, boring operations (2), 

 Ontario (4), Quebec (1), New Brunswick (1), Nova Scotia (3), 

 and Hudson Strait (2). 



Experimental borings in petroleum - bearing rocks were under- 

 taken in Northern Alberta (N.W. Territories) with results which 

 pointed to the existence of an oil-field of great extent in that region. 



Following the account of this work, which is given in much detail, 

 are the reports of the officers responsible for the Museum, Herbarium, 

 and Library of the Survey. 



The first field report (F) is that of Mr. W. Mclnnes, on the 

 geology of the area covered by the Seine Eiver and Lake Sheben- 

 dowan map-sheets, comprising portions of Eainy River and Thunder 

 Bay Districts, Ontario. After describing the physical characters of 

 the region, its principal rivers, lakes, waterfalls, wild animals, forest 

 growth, etc., the author deals with its geology. The geological 

 formations are as follows, in descending order : — 



Surface deposits of glacial and lacustrine origin. 



Animikie. 



Steep Eock. 



Keewatin. 



Coutchiching. 



Laurentian. 



The most widely distributed of these is the Laurentian, which 

 occupies more than three-fourths of the entire area. It is made up of 

 granite-gneisses, which vary in composition according to the presence 

 or absence of hornblende, and in the distinctness of their foliation. 

 The typical rock is a biotite-granite-gneiss made up of quartz, 

 orthoclase, plagioclase, and biotite, generally distinctly foliated and 

 banded with finer and coarser layers. The non-foliated, central 

 poi-tion merges gradually, at varying distances from the edge of 



