MARBLE ISLAND. 199 



tions " quartz, enclosing chlorite and copper-pyrites ; carbonate and 

 silicate of copper, with copper-pyrites on argillaceous slate ; ditto, 

 with a thin coating of green carbonate of copper." 



Judging from what Professor Tennant says as to a few rock- 

 specimens which were submitted to him from Repulse Bay and vicin- 

 ity, 300 miles northeastward of Marble Island, the Huronian rocks 

 would appear to occur there also. One specimen from this l>ay, he 

 describes as " quartz coloured bv oxide of iron and containing minute 

 particles of gold." The existence of visible gold in quartz at Repulse 

 Bay is an important fact. It has been already mentioned that gold 

 and silver were'found by assay-in a specimen of iron pyrites from a 

 bay soutli of Ckpe-Johes, not far south-west of Marble Island. Both 

 gold and silver have been discovered by assay in specimens of quartz 

 or pyi ites which T have brought fi'om various parts of Hudson's Bay 

 and Straits. In 1877, Dr. Harrington, who was then chemist to the 

 Geological Survey, detected both gold and silver in iron pyrites which 

 I had collected from a small vein cutting gneiss on a point about one 

 mile south of the mouth of Great Whale River, and also in pyrites 

 from veins in the dolomite which forms Dog Island, close to the main 

 shore, A few miles north of the Cape Jones of the East-main coast. 

 The galena df the old mine,- about three miles north-east of Little 

 Whale River trading post, was found to contain 5104 ounces of 

 silver to the toil of 2,000 lbs., arid that from the south side of the inlet 

 of Richmond Gulf, 1203 ounces to the same quantity of ore. More 

 recently, Mr. Hoffmann, now chemist to the Survey, has found 

 small quantities of gold and" silver in quartz which I obtained from a 

 thin vein on one of the Ottawa Islands, in the north-eastern part of 

 Hudson's Bay. He has also proved the occurrence of the precious 

 metals in quartz veinstones, which I Ijrought from Cape Prince of 

 Wales, about the middle of the soiith side of Hudson's Straits ; Cape 

 Chudleigh, on the south side of the eastern entrance to the Straits ; 

 and Nachvak Inlet, on the Labrador coast, about 140 miles south 

 of the last mentioned cape. 



From the data I have gathered at Marble Island and that afibrded 

 by the valuable series of specimens which I have referred to, as well as 

 from the fact that Laurentian types of rocks are absent from the col- 

 lections, it is to be inferred, as already stated, that we have a great 

 development of the Huronian series along the 180 mites of coast from 

 Chestel'tield Inlet to Eskima Point, both in i-egard to the variety of 



