4 2 2 C. K. LEITH 



and volcanic agglomerates. The fine grained traps are interbedded 

 with the clastic rock. No acid eruptives appear. On the east coast of 

 Hudson Bay and at Chateau Bay near the eastern entrance of the 

 Strait of Belle Isle, some of the traps have formed overflows on 

 the surface, and are now represented by dark green, finje-grained 

 melaphyres having large amygdaloidal cavities filled with quartz and 

 agate. No fossils have been found in these supposed Cambrian rocks 

 and their precise age and equivalency can only be conjectured. How- 

 ever, the mode of occurrence of thick beds of magnetic iron ore over- 

 lain by cherty, nonfragmental carbonates in this series, closely resembles 

 that of the iron ores of the Lake Superior region described by Irving, 

 Van Hise, and others. This, with other characters of resemblance, 

 renders it almost certain that the two developments represent the 

 same period, or, in other words, that the Animikie rocks of Lake Supe- 

 rior, assumed to be Lower Cambrian, are equivalent to the rocks here 

 described as Cambrian in Labrador. 



Low 1 reports on a traverse of the northern part ot the Labrador 

 peninsula, from Richmond Gulf to Ungava Bay. Laurentian rocks 

 occupy the greater part of the area. These are chiefly granites, more 

 or less foliated. They are of different ages, but, except in a few cases, 

 they cannot be discriminated. Cutting them are intrusive diabases. 



Intimately associated with the granites is a series of more or less 

 quartzose mica-gneisses and mica-schists, interbanded with hornblende- 

 schists and hornblende-gneisses ; and at times with quartz-magnetite 

 gneiss. These gneisses and schists are supposed to represent a bedded 

 series of rocks somewhat similar to the Grenville series. While most of 

 the schists are thus probably very ancient, others may be of the same 

 age as the Cambrian. 



Cambrian rocks were met with along the east coast of Hudson 

 Bay, to the northward of Cape Johns, and on the Larch River from its 

 junction with the Kaniapiskau upwards for thirty miles. A section 

 examined on the east side of Castle peninsula, on the north side of the 

 outlet of Richmond Gulf, presents rocks closely resembling the 

 Mesnard quartzites and the Kona dolomites of the Lower Marquette 

 series of the south shore of Lake Superior, capped by a later outflow 

 of trap, classed as Algonkian by Van Hise. 



1 Report on a traverse of the northern part of the Labrador peninsula, from 

 Richmond Gulf to Ungava Bay, by A. P. Low: Ann. Rep. Geol. Surv. of Canada 

 for 1896, Vol. IX, 1898, Part L, pp. 1-43. With geol. map. 



