338 



MINERALS AND GEOLOGY 



titaniferous ii'on Bands are abundant around the mouth of the Moisie 

 river on the Gulf. Attempts to utilize these titaniferous ores have 

 been made, but hitherto without success.* 



In addition to the gneissic and other crystalline formations of tins 

 northern archsean region, a few outlying patches of Lower Silurian 

 strata, consisting mostly of Trenton limestone and Utica shales, 

 occur here and there within its area. The largest of these Silurian 

 outliers is seen around Lake St. John on the Upper Saguenay. As 

 remarked by Sir William Logan, the limestones at this locality shew 

 characteristic Black River fossils associated with those of the Trenton 

 formation proper,! and comprise principally : Maclurea Loyani 

 (fig. 222); Stromatopora rugosa (fig. 127) Orthoceras Biysbyi ; Lep- 

 tcena sericea (196) ; Strophomena cdternata (fig. 194); Murchisonia 

 gradlis (fig. 220) ; Calymene Blumenbachii (fig. 179), etc. with, near 

 the base of the series, Halysites catemdatus (fig. 139), typically, an 

 Upper Silurian form. The fossils of the overlying Utica shales in- 

 clude various graptolites, broken crinoidal stems, species of discina, &c., 

 and the characteristic Utica trilobite Triarthrus Beckii (fig. 177). A 

 small exposure of Hudson River beds is seen also on Snake Island in 

 the lake. 



Glacial boulders, clays, and gravels, with Post-Glacial sands and 

 other superficial deposits, are distributed, as in other parts of Canada, 

 more or less generally throughout this region ; and many of the 

 harder rocks shew glacial striae. These run most commonly either 

 towards the south-east or south-west ; but at some spots their direc- 

 tion is nearly north and south \ and, in others, not far removed from 

 east and west. 



DISTRICT OF THE UPPER ST. LAWRENCE. 



This is essentially a Palseozoic area, occupied apart from some 

 isolated eruptive-masses by sandstones, limestones, and other strata, 



* The presence of titanium in an iron ore is objectionable chiefly for the following reasons : 

 (1) It diminishes, of course, the percentage of iron in the ore ; (2) it renders the ore very re- 

 fractory ; and (3) it scours the ore, carrying off a large amount of iron in the form of slag. To 

 prevent the latter effect, a comparatively large amount of lime is required, and this fills up the 

 furnace with an unproductive burden. Very little titanium goes into the pig metal, even when 

 highly titaniferous ores are used. 



t A similar association of Black River and Trenton types was pointed out by the author, 

 many years ago, as occurring at Shannonville in Ontario. The two so-called formations cannot 

 in fact be properly disunited. 



