134 GLACIATED PEBBLES 



pebbles into the greenish blue tillite. The glacial beds 

 pass upwards into shale without pebbles by decrease in 

 the number of pebbles and at the same time the ap- 

 pearance of lamination planes. 



Recently a number of typically scratched pebbles and 

 boulders l have been found on the " table " of Table 

 Mountain itself, on a horizon 2,250 feet above the base 

 of the series. The bed containing these boulders and 

 pebbles lies at the base of the Kopje on which Maclear's 

 beacon stands, and the pebbles and boulders are mostly 

 found weathered out from the matrix and scattered over 

 the plain from which the Kopje rises. Many of them are 

 an inch or so in length, and are made of white quartz and 

 quartzite ; they had been well water-worn before they 

 were striated. Fewer are of much larger size, varying up 

 to a foot in length, and these show the characteristic shapes 

 and scratches extremely well. Some of those boulders 

 were found still embedded in the matrix, a gritty quart- 

 zite very unlike the dark-coloured mudstone of Clan- 

 william. Though white quartz and quartzite are the 

 most frequent materials, dark-coloured cherts, granite, 

 and reddish coarse gritty quartzite, very like many of 

 the Matsap quartzites, were found in this locality. 



A very interesting quartz pebble is amongst those 

 collected on Table Mountain ; it has the character of 

 sand-cut pebbles from desert regions, rather sharp but 

 not quite straight edges separating nearly flat but slightly 

 undulating faces; it is in shape a typical " driekanter ". 



The only traces of fossils yet found in the Table 



1 First found by Dr. R. Broom in Nov., 1908, and a few days later 

 the writers found many other examples. 



