24 THE MALMESBURY SERIES 



and phyllites with thick bands of schistose quartzite. 

 The whole series has been folded, usually isoclinally, 

 that is the dips of both limbs of the fold are inclined in 

 the same direction, to the west. The middle or Aties 

 group is the most interesting and occupies a belt of 

 country at least sixteen miles wide across the strike 

 from Van Ehyn's Dorp westwards. The limestones 

 which are so abundant in this division are usually blue 

 or grey in colour, but dark varieties are also found ; car- 

 bonate of magnesium is contained in some of them. 

 Along with the folded limestones are black highly car- 

 bonaceous and pyritic slates, and also layers of brown 

 or black limonite. In the Kobe Valley there are dark 

 red banded jaspers in contact with the limestone. 



Thick bands of crystalline limestone are found inter- 

 bedded with the slates near Piquetberg, Saron, Vogel 

 Vlei (south of Porterville Eoad Station) and on the 

 Berg Kiver near Hermon. They also occur at Bakoven's 

 Hoogte between Ashton and Swellendam, in Dassie's 

 Hoek near Kobertson in association with black slates, 

 and in thin bands north of Worcester. Schists contain- 

 ing the chloritoid mineral ottrelite are found in thin 

 bands near the junction of the Malmesbury beds with 

 the unconformably overlying Table Mountain series in 

 Waai Kloof near Worcester (Plate I.) and north of the 

 town of Swellendam. In both cases thick quartz 

 schists occur on one side of the ottrelite schist, but no 

 granite or other intrusive rock has been found penetrat- 

 ing the intensely compressed slates in the immediate 

 neighbourhood. In George there is an elongated area 

 of slates and quartzites, the former being sometimes 



