﻿Trof. Milne and Alex. Murray — llochs of Newfoundland. 259 



a fractured surface. However, when one is obtained, the interior of 

 the rock is seen to be chloritic. 



Still further to the south, about Bluff Head and Louis Hills, we get 

 a series of weathered araygdaloidal rocks, which may be defined as 

 melaphyres. They have generally an argillaceous smell, and are 

 calcareous, especially in their joints and amygdules. Under the 

 microscope there can be seen, a finely granular ground mass, a much 

 kaolinized felspar apparently labradoi'ite, and sometimes a mineral 

 which brilliantly polarizes, which may be olivine. On the whole, 

 they are like altered dolerites, and all of them have a more or less 

 chloritic look. In places disseminated through the mass there is a 

 bituminous mineral, and very often specks of native copper. These 

 minerals are chiefly found in the more decomposed portions of the 

 rock. Up Louis Brook some true serpentines are to be found, and also 

 a dolomite. Comparing these rocks on the west side of the island 

 with those of similar age upon the east, they only seemed to me 

 to differ in the degree of alteration which they had undergone. 

 And those upon the west in this way tend to confirm the idea of the 

 volcanic origin of the greater part of this series, as exposed in New- 

 foundland.^ 



Southern and Central Exposures. — In the southern and central 

 exposures of this series, about Bay East River, we get serpentines, 

 chloritic and talcose slates, felsites and micaceous slates. The rocks 

 on the w-hole having a lithological likeness to the other members of 

 the same series. 



Taking a general review of this formation, as presented to us in 

 patches, some of which are more than 100 miles apart, one cannot 

 but be struck with the great lithological similarity which runs 

 throughout the whole. In comparing lists of specimens taken from 

 different localities, it is found that some are almost identical. The 

 rocks everywhere contain serpentines and chlorites, are magnesian 

 in their character, and always contain more or less of some valuable 

 mineral matter like ores of copper. Sometimes their nature is at 

 once to be seen, whilst in other cases it is only with difficultj^ to be 

 recognized. Everywhere they show traces of having been derived 

 from volcanic rocks, and in all cases the alteration to which they 

 have been subject is similar, and has only differed in amount. 

 Looking at the vast hills which yet remain of these rocks, they appear 

 as relics of large and powerful volcanos which were in activity 

 belching out showers of ashes and pouring forth great streams of 

 lava in Mid-Silurian times.^ 



If this view is a correct one, then there was a period when 

 quiescent, dreary Newfoundland was like a modern Iceland. Since 

 that time, however, great changes have happened, and processes of 



^ I have already alluded to the probable age of tbe igneous rocks, and to the 

 geological position of tbe serpentines on the west coast of the island. — A.M. 



^ This view is not improbable, but I am inclined to think, from the undistnrbed 

 state of the rocks already spoken of at Long Point, Port-a-Port Bay, that the time of 

 greatest volcanic activity must have been at an earlier date, probably within the 

 Chazy or Trenton periods. — A.M. 



