l62 



beds diminish in thickness and number and become very 

 rare, while the quartzites increase in thickness and 

 become massive, coarse and more siliceous. The thickness 

 of the Golden ville formation, estimated to be 16,000 feet 

 (4,877 m.) at Moose River, Halifax county, was found by 

 Faribault in 1912, to exceed 23,700 feet (7,242 m.) on 

 Liverpool bay, Queens county. 



Halifax Formation. 



The Halifax formation is composed essentially of 

 argillaceous and siliceous slates of different colours, but 

 mostly dark grey and black, graphitic and pyritous, 

 passing at certain horizons into greenish and bluish grey 

 talcose argillites, or into ribboned grey and light grey, 

 chloritic, arenaceous beds. The black slates have numerous 

 layers of flinty flags heavily charged with small cubes 

 of pyrite which also occurs in massive form between the 

 beds. The base of the formation is characterized, in 

 some places to the eastward of Halifax, by a few beds of 

 siliceous limestone. At the eastern end of the field the 

 line of demarkation between the Goldenville and this 

 formation is well defined by a sudden change from quartzite 

 to slate, but at the western end the transition is more 

 gradual and beds of quartzite are found interstratified 

 with the beds of grey arenaceous slates of the overlying 

 formation. 



The thickness of the Halifax formation, as measured 

 on the Black river to the base of the Whiterock quartzites 

 of the Gasperau formation, is 11,700 feet (3,566 m.). 



Metamorphic Phases. 



Crystalline schists and gneisses of various kinds are 

 found rather widely distributed throughout the field, but 

 are of limited area. They usually occur in more or less 

 continuous zones surrounding the granite masses, but 

 they are also found in zones or irregular patches several 

 miles distant from any outcrops of granite. 



The gneisses consist chiefly of quartz and mica and are 

 foliated and coarsely crystalline. The schists are mostly 

 composed of mica often accompanied by crystals of 

 staurolite, or andalusite, less commonly, by hornblende 

 or garnet. Some layers are highly charged with pyrite 



