PRE-CAPE ROCKS OF THE NORTH OF THE COLONY 75 



same strike as far south as Maritz Dam and evidently 

 underlie the greater part of Herbert and Hopetown. On 

 the west side of the Transvaal formation in Prieska and 

 Hay the Pniel series has been much crushed, folded and 

 faulted, but it extends almost continuously from Uit- 

 spansberg to Zeekoebaart. Towards the south-east it 

 has been cut out by faults on the flank of the Doorn- 

 bergen, but from Uitspansberg to Kameelboom a thin 

 belt of lavas, often very much sheared, lies between the 

 granite and some member of the Transvaal system. At 

 Wit Vlei there is a coarse conglomerate with boulders 

 of acid lava, but conglomerates and other sedimentary 

 rocks are not frequent in the Prieska area. Towards 

 Ezel Hand the area of Pniel beds widens out greatly, 

 and some breccias containing granite fragments lie at or 

 near the base of the series on the west side. The Pniel 

 beds have been much sheared in Prieska, especially near 

 their junction with the granite. In places they have 

 been converted into slaty phyllites, in which the amyg- 

 dales form " eyes," and at the granite contact there is a 

 zone of sheared breccia probably produced in places by 

 earth-movements ; near Schalks Puts large masses of 

 granite are found in the lavas, showing sheared contacts, 

 and the lava occurs similarly in the granite. The con- 

 tact zone shows no sign of modification due to igneous 

 intrusion. 



D. THE KOEAS 



About thirty-five miles above Upington the Orange 

 Eiver enters an area made of red rocks, lavas, conglo- 



1 Described in G. C., xii., p. 52. 



