452 Annals of the South African Museum. 



conglomeratic beds which are composed of debris and fragments of 

 granite. In places the fine-grained sandstones lie directly on the 

 granite without intervening conglomerates. 



At Slypsteen Drift the sandstones are even in texture, fine-grained 

 and often massive; some beds show a tendency to lamination and 

 are at times false-bedded. Wm. Anderson, in a paper published in 

 19112, described the occurrence of fossiliferous beds "exposed in the 

 water-channel of the Compies River, in the vicinity of the store at 

 Stypstee Drift, Springbok Flats, Waterberg District". "Stypstee Drift" 

 is presumably a misprint, and should read "Slypsteen Drift". Regarding 

 this occurrence Anderson writes "As this is the only postion in which 

 I observed outcrops of these fossiliferous sedimentary beds, I have 

 no evidence as to their probable lateral extent or distribution, because 

 the country to the north-east, west and south-west chiefly consists 

 of extensive areas of alluvial deposits, through which occasional out- 

 crops of Recent calcareous rocks are not uncommon .... To the 

 westward of Stypstee Drift, under the alluvials of the Springbok Flats, 

 these fossiliferous sedimentary beds probably become associated with 

 the arnygdaloidal basalts, which form a portion of the Upper Karroo 

 Series, and are well developed in the western and south-western 

 portion of the Flats. It is, however, probable that this occurrence 

 of fossiliferous Upper Karroo beds is not continuous with those of 

 the west, but has been formed in an isolated basin. Similar, probably 

 cniitemporaneous, sandstones and shales occur at the foothills of the 

 western limit of the Springbok Flats, the sandstones occasionally 

 attaining a considerable individual thickness, as at Buiskop, to the 

 north of Warmbaths, where the rock has been extensively quarried 

 for building purposes." According to Anderson, the beds at Slypsteen 

 Drift rest unconformably on the Red Granite of the Bushveld. In 



\j 



the main section the lower exposed strata consist of practically 

 horizontal exceedingly fine-grained, light grey, argillaceous shales. 

 The sandstones above are markedly false-beddnl and much jointed 

 vertically. "In all cases the fossil bones occur as the nuclei of 

 ferruginous nodules and not in a free state in the sediments. They 

 occur more frequently in the nodules from the sandstones, but are 

 more fragmentary than are those from the shale nodules. On all 

 the exposed outcrops these beds do not show the slightest evidences 

 of deposition under violent climatic conditions, although the presence 

 of frequent bone fragments in the ferruginous nodules, which have 

 evidently been much worn by attrition before they were deposited 

 in the sediments, would rather incline one to the idea that there 

 must have been around this lake-basin areas in which considerable 



