in Norway and in Canada. IIS 



in some places to pass into a grey, coarse, splintery, quartzose 

 hornstone ; while the gneiss gives a red or brown hornstone, with 

 fine splintery, and nearly smooth fractures. 



5. Hornblende slate. 



6. Talc slate. 



I. Chlorite slate. 



8. Clay slate. 



9. Limestone has only been remarked at one place in the whole 

 group, where a thin bed of granular yellowish-white limestone, 

 occurs in the quartzose gneiss. 



10. Greenstone and diorite, composed principally of albite and 

 hornblende, occur in large and important masses. 



II. Granite does not seem to occur interstratified with the 

 members of this group, but frequently intersects them in the 

 form of veins, and also forms irregular masses. 



12. Conglomerates and breccias occur in such quantity, and of 

 such peculiar characters, as to constitute a distinguishing feature 

 of the formation. The whole of the rocks already named as 

 forming part of this group, but especially the quartzites, often 

 contain beds or irregular masses, having the aspect of conglo- 

 merates ; which are made up of fragments of the respectively en- 

 closing rocks, cemented together either by a micaceous or talcose 

 substance. The fragments are more or less rounded, and often 

 of oblong forms ; they generally lie parallel with each other, but 

 very often bear little resemblance to boulders. 



The rocks just enumerated, form layers, often of enormous 

 thickness,which alternate with each other, forming parallel groups, 

 in which one or the other of them (generally the quartz), predo- 

 minates. The fine and coarse grained greenstones or diorites of 

 the formation, are most generally in layers running parallel with 

 the other rocks. They sometimes however occur as veins cutting 

 these, and more frequently as irregular masses. The greenstone 

 beds are often of great extent, and pass through gradual transitions 

 into the neighboring rocks. A layer of diorite occurs in the 

 parish of Skafse, having a thickness of 1000 feet. In the middle 

 it is granular, but towards each side, it gradually assumes a slaty 

 texture. It has also been remarked of other greenstone layers in 

 the group, that they assume a slaty structure, as they approach 

 the rocks above or below them. Keilhau has the following re- 

 marks with regard to the extent which these greenstone or diorite 

 rocks occupy in the series before us. '* We may obtain a good 



