I3i 



KiVometre^ excavation is now 500 feet (152-3 m.) long, 

 200 feet (60-9 m.) wide and 130 feet (39-6 m.) 

 deep, all of which work has been done in 

 the last 8 years. 



Crossing Thirteen Island lake, and Thirty 



Island lake, and about half 



35 m. Glendower a mile west of the latter 



56 km. Iron Mine, lake are the old pits of the 



Glendower Iron mine. The 

 mine is situated at, or close to the contact of 

 Grenville gneisses with crystalline limestone. 

 The property was worked from about 1873 

 to 1890, but has since been idle, apparently 

 on account of the increase in sulphur in the 

 ore beyond a depth of 150 feet (45-7 m.), 

 where iron pyrites became so abundant as 

 to render the ore unfit for use. 



The occurrence of interest at this point is 

 the so called "plagioclase scapolite diorite" 

 of Adams and Lawson, [5]. In the excursion 

 to the lead, phosphate and mica deposits, it 

 was noted that a series of pyroxenites, which 

 cut up through the Grenville gneisses and crys- 

 talline limestones, were constantly associated 

 with the apatite deposits. In places these 

 intrusives appear to have been more acidic 

 in character, becoming augite diortites which 

 contained originally augite, hornblende, pla- 

 gioclase, and some quartz. The hornblende 

 so predominates that when foliated, they have 

 been called amphibolites. In places they 

 present a mottled appearance, closely resemb- 

 ling the "geflecter gabbro" associated with 

 the apatite occurrence in Norway. This 

 mottled appearance is due to concentrations 

 of black, coarsely crystallized hornblende in 

 a lighter colored ground mass, made up of 

 scattered hornblende crystals in a greenish 

 waxy looking mineral of feldspathic appear- 

 ance. This lighter portion is more easily 

 weathered than the hornblende spots and is 

 often somewhat sunken below the general 

 surface. 

 35064—91 



