PRE-CAPE ROCKS OF THE NORTH OF THE COLONY 61 



The beds have been intensely folded and considerably 

 faulted, and they occur as narrow strips seldom more 

 than two miles wide, flanked on either side by granite 

 and gneiss. In Mafeking there are three of these schist 

 belts with a general north and south strike ; one passes 

 through Mosita, one through Pitsani and Kraaipan (ex- 

 tending southwards into the Transvaal and northwards 

 into the Protectorate), and one is at Madibi. This 

 formation is much older than the Ventersdorp system, 

 for rocks belonging to the latter rest upon the steeply 

 dipping schists in several localities, and contain boulders 

 derived from them. 



The rocks resemble the beds of the Swaziland system 

 of the Transvaal but they cannot as yet be correlated 

 with that formation, for while the "old granite " of the 

 Transvaal is intrusive in the latter, the granite and 

 gneiss of Mafeking appear to be much older than the 

 Kraaipan formation. 



Junctions with the granite are rarely seen owing to 

 the thick mantle of red sand, but the few observed con- 

 tacts show either a normal unconformable junction or a 

 faulted contact, and no veins of granite have yet been 

 found traversing this formation. 



The best sections are to be seen at Kraaipan, where 

 the junction is visible in a cutting along the railway. The 

 whole formation dips eastward at a high angle and the 

 granite is brought up again on the east by a large fault. 

 On Wodehouse Kraal the upward succession is as 

 follows : (1) a zone of massive magnetic quartzites, (2) a 

 zone of light-coloured cherts, chlorite slate, diabase, etc. 

 The softer beds are rarely seen except in artificial 



