118 Transactions of the South African Philosophical Society. 
In the case of one rock at Jackal’s Water, an almost perpendicular 
face about 8 feet high lies in the direction of the average trend of 
the striz on the other rocks, and this face is well scored. Towards the 
upper part of this wall the scored and polished surface passes round 
the edge of the rock and is continuous with the polished top of it 
(Fig. 1). A similar feature has been observed in other more recently 
glaciated regions, notably Vancouver Island.* It is particularly 
noticeable that the lower parts of the hills alone show the striations. 
The upper portions have long since lost all trace of them owing to 
the action of the weather, and have the very rough surface 
characteristic of the hard rocks of this district which are exposed 
to the great variations in temperature and are unprotected by 
vegetation. 
A 
NS 
Conglomerate Oz GS 
Gas 
ee 
~~ KK 
Fic. 1.—SECTION THROUGH THE VERTICAL STRIATED FACE OF QUARTZITE, 
JACKAL’S WATER. AAA, SCRATCHED SURFACE. 
At Klein Modder Fontein, some 15 miles to the 8.S.E. of Jackal’s 
Water the same range of quartzite hills passes under the large area 
of conglomerate in the south of Prieska. The same phenomena 
are seen here as at Jackal’s Water, but less well displayed. The 
direction of the striae and smooth slopes here also indicates that the 
ice moved towards a point a few degrees west of south. 
* G. W. Lamplugh: On ice-grooved rock surfaces near Victoria, Vancouver Is. 
Yorksh. Geol. and Polyt. Soc., vol. ix., pl. 6. 
