BY DR. W. N. BENSON. 31 



14C4. Mica-schist with a lenticular schistose tex- 

 ture consisting of granoblastic quartz, with 

 large irregular poi'phyrcblasts of orthoclase, 

 generally blackened by inclusions of carbona- 

 ceous matter. These have resisted the shear- 

 ing much better than the quartz, and are a^ 

 frequent cause of the irregularity of the lenti- 

 cular texture. A pale green mica is abun- 

 dantly developed in the numerous shearing 

 planes, and extends out from them. Sericite 

 is also present, and a very little andalusite and 

 rutile. 



1465. Mica-schist with lenticular texture, consist* 

 ing of long irregular lenticles of close-packed 

 pale green weakly pleochroic mica, partially 

 chloritised, separated by layei^ of granoblastic 

 but more or less elongated quartz grains. Large 

 porphyroblasts of felspar, generally orthoclase, 

 but also albite, interrupt the continuity of the 

 lenticles of mica and quartz. Inclusions in 

 these often continue the planes of schistosity. 

 Small grains of magnetite are scattered 

 throughout the rock, and a few grains of an- 

 dalusite have been noted. 



1466. A much crushed schistose quartzite, exhi- 

 biting joerfectly the klasto-porphyritic struc- 

 ture. It consists of large quartz-grains with very 

 undulatory extinction and shattered margins, a, 

 few irregular uncrushed grains of albite, and a 

 ground mass of finely comminuted quartz, with 

 a few shreds of sericite. 



All these rocks are characteristic of the uppermost 

 zone of Griibenmann's classification of the crystalline 

 schists. This bears out Mr. Wards view concerning their 

 nature. 



'lae Permo-carboniferous rocks lie on a very uneven 

 surface of the crystalline schists. The irregularity is par- 

 ticularly clear under Mount Brown, on the southern side 

 of Rodway Gorge. The basal portion of the series con- 

 sists of conglomerate containing pebbles derived chiefly 

 from the Pre-cambrian series, but also from the Devonian 

 granites and other formations. They pass up into' pebbly 

 sandstones and mudstones. A thickness of about seventy 

 feet of conglomerate occurs beneath the north end of 

 Cradle Mountain, but this increases considerably to' the 

 wsouth and east. There is apparently not less than five 

 hundred feet of the sediments beneath Mt. Brown, while 



