PRE-CAPE ROCKS OF SOUTH AND WEST OF COLONY 33 



Small areas of granite intrusive in the Malmesbury 

 beds are known in the south of Caledon, in the Hemel 

 en Aarde and Zondag's Kloof valleys, and again in the 

 western part of Bredasdorp. 



In the narrow strip of Malmesbury beds north of the 

 Worcester fault there are at least three granitic intru- 

 sions, all of /which have been considerably affected by 

 earth-movements since their intrusion, and to some 

 extent probably by movements during their consolida- 

 tion. There is an abundance of phyllite-gneiss, a rock 

 looking very like a highly micaceous clay-slate with 

 " eyes " and thin strings of obviously igneous material, 

 composed of quartz, orthoclase and mica. The ortho- 

 clase crystals often form the " eyes " with little other 

 granite material in the same lenticular area. The 

 largest mass of granite forms the high ridge just west 

 of Eobertson. 



The last granite area in the south of the Colony that 

 must be mentioned is the intrusion in George. 1 This 

 mass is about thirty miles in length from west to east 

 and from four to eight miles wide ; in the east there is 

 a dyke-like offshoot which spreads out into the Touw's 

 River boss. Round ' the borders of these masses the 

 strata are heavily injected with granite dykes. The 

 granite varies greatly in composition, but is for the 

 most part a muscovite variety though biotite-granite is 

 represented in places ; tourmaline and fluorite are also 

 found. As a result of shearing, portions of the granite 

 have acquired a gneissose structure, while basic intru- 

 sions have been altered into hornblende schist. 



1 G. c., x., p. 51. 

 3 



