40 ON FELSITES AND ASSOCIATED ROCKS. 



resulted from tin* foliation of sandstones : and (juartis 

 schists, probably from ({uartzites : and talc schists, as on 

 the Jupiter section, \vhich must have had a ditferent 

 •origin from the ar^illitic and quartz series. Talc schists 

 are most likely to originate from pjroxenic rocks, but 

 nothing is known yet of the relations of the Jupiter rocks. 

 Micaceous schists occur, but not the true mica schists 

 of the gneissose Archaean series. At Cutty Sark, near the 

 Pieman River, there is a dark, compact, granular rock, 

 -of doubtful origin, which has been involved in the move- 

 ments of the chain, and received an impress of schistosity. 

 In fact, all through this zone of metamorphism and folia- 

 tion, no matter what kinds of rock, they have been caught 

 np in the process of schist formation, their original characters 

 more or less obliterated, and a new stamp of rock structure 

 impressed upon them. An exceptional occurrence in the 

 -schist zone is the Mount Black lode at Rosebery, which is 

 3, banded true fissure lode containing gold, wolframite, bor- 

 nite, bismuthinite, chalcopyrite, iron and arsenical pyrite, 

 and black tourmaline. The occurrence of wolframite and 

 tourmaline is noteworthy. Just south of this, at the South 

 Mount Black, is a dj^ke, black with tourmaline. The acid 

 nature of this dyke and lode seems to indicate some con- 

 nection with the movements of the granite magma in the 

 West Coast area. This relationship naturally involves a 

 much younger age than that of the surrounding schists 

 and felsites. The tourmaline quartz-porphyry at South 

 Renison Bell, the axinite at the Colebrook, and the Mount 

 Black fiuor and tourmaline rocks, probably all l)elong to 

 one and the same eruptive phase. 



The schists are repositories of numerous minerals and 

 ores, which vary in the extent of impregnation to both 

 •exti'emes, inasmuch as these are more commonly simply 

 represented by a few^ sparsely scattered minute crystals 

 and flakes of pyrites, often of a cujiriferous tendency, with 

 occasional patches of galena and zinc sulphide. More 

 rarely these metallic minerals are found in great quantity, 

 sometimes w^holly replacing the substance of the rocks, 

 until they assume the character of a dense mass of sulphide 

 ore of enormous extent. It is such masses of mineralised 

 schist which are operated upon by the miners in the 

 districts of Mount Reid and Rosebery. The change does 

 not assume a general character, for often within a restricted 

 area one or other of the copper, lead, zinc sulphides 

 preponderates ; but, as a rule, zinc is present. At the 

 Tasmanian Copper and adjacent mines the ore is practi- 



