50 B GEOLOGICAL SURVEY OF CANADA. 



closely associated with it, are igneous rocks, apparently contemporan- 

 eous. The most abundant is dark blackish-green, spotted, and may be 

 called a diabase, though it is difficult from its decomposed character to 

 determine the several ingredients. In it are masses, irregular in form 

 and perhaps concretionary, of paler felspathic material, which project 

 on weathered surfaces and assume a brown sub-metallic jjolish. 

 Supposed ar- It would be hazardous to attempt to delineate the course of the beds 



rangement of . - 1 



beds. in the Houston Stewart region on the information obtained. It may 



be, however, that the limestone just described represents the continua- 

 tion of that on the opposite side of the channel, which may run with its 

 associated argillites up the centre of Rose Harbour, and so through to 

 South Cove in Carpenter Bay, where the argillites are again found. 

 In this case the limestone exposures near the mouth of the Sedmond 



Fossils from Eiver, at the head of Eose Harbour, would represent the same bed on 

 Rose Harbour. ' \ r # 



the opposite side of a narrow synclinal occupied by argillites. The 



fossils obtained in this place, however, differ from those of the first- 

 mentioned locality in facies. Mr. "Whiteaves recognizes in the lime- 

 stone imperfect casts of lamellibranchiata and gasteropoda, which 

 seem to belong to the following genera : — 



1. Pecten, cr Aviculopecten, one species. 



2. Cardiomorpha (?), two species. One with radiating ribs, like 

 C. radiata, DeKoninck ; the other with smooth surface. 



3. Loxonema (or Murchisonia), one species. 



4. Macrocheilus, near M. canaliculatus, McCoy. 



5. JSaomphalus, sp. nov. (?) 



These fossils resemble those from the point at the east side of the 

 entrance to Eose Harbour, and can scarcely be newer than the Triassic 

 formation or older than the Carboniferous. 



The rocks seen elsewhere in Eose Harbour are igneous, massive, and 

 may either be contemporaneous with the limestones and argillites or 

 of subsequent origin. At the west entrance point occurs a grey 

 felspathic amygdaloid, the cavities in which have been lined with a 

 chloritic mineral and then filled with quartz, with in some cases a 

 little copper pyrites. From this point to Fanny Point, at the seaward 

 opening of the inlet, its north-west side appears to be entirely com- 

 posed of greenish felspathic or dioritic rocks, probably bedded but 

 much altered. 



From the eastern opening of Houston Stewart Channel the north- 

 east side of Prevost Island is composed, where examined, for seven 

 miles, of greenish rocks, apparently for the most part dioritic and 

 probably bedded, with general north-westerly and south-easterly 



Igneous rocks. 



