MARBLE ISLAND. 197 



miles in a straight line. They include a considerable variety of 

 species, and from them it is manifest that the Huronian series is 

 well developed and occupies a large area on the north-west side of 

 Hudson's Bay. This would be a highly important fact, even if the 

 collection referred to contained no direct evidence of the existence 

 there of economic minerals, because we already know, from an exten- 

 sive examination of these rocks in other parts of the Dominion, that 

 they constitute the repositories of numerous metallic ores and other 

 useful minerals, while the primitive Laurentian rocks are almost 

 destitute of them. But in this collection there are eleven specimens 

 of granular iron pyrites, from different parts of this coast, all of which 

 apparently contain small quartz gi-ains. Most of the specimens 

 are angular, and their aggregate weight is about fifty pounds. Mr- 

 Hoffmann, chemist to the Geological Survey, has made an assay of 

 one of these specimens from a bay south of Cape Jones, which forms the 

 southern horn of Rankin Inlet, and found it to contain traces of both 

 gold and silver. A good sized angular piece of similar pyrites, which I 

 obtained from the Eskimos in 1879, and which they brought from a 

 place called Inai^i, described as being about two-thirds of the distance 

 from Churchill Harbour to Marble Island, had a small quantity of 

 light bluish-grey magnesian limestone adhering to it. Some of the 

 other specimens of this pyrites have small pieces of soft dark-greenish 

 schist attached to them. 



The specimens from the above-mentioned 180 miles of the north- 

 west shore of Hudson's Bay embrace the following rocks : Chloritic 

 schist, dark chert)^ schist, hard dark argillaceous slate, finely i-ibboned 

 hornblende and quartz schist, imperfect gneiss, dark silicious breccia 

 with calcspar, dark-green crystalline pyroxene rock, dark chocolate- 

 coloured silicious argillite with conchoidal fracture, calcspar vein- 

 stones, semi-translucent white quartz, red aplite of medium texture? 

 rather fine-grained grey granite, grey diorite, consisting of light- 

 coloured felspar and dark hornblende in small distinct crystals, giving 

 it an even and finely speckled appearance, fine-gi-ained hornblende 

 schists, greenstones, quartz and epidote rock, light grey coarse 

 grained sandstone altered to quartzite and holding fragments of 

 indurated red shale, compact banded white quai'tz-rock with crystals 

 of iron pyrites in some of the layers, light quartzite like that of 

 Marble Island, grey felsites, crystalline hornblende-rock, diorite, 

 consisting of compact white felspar with long crystals of dark horn-. 



