GEOLOGY OF THE NEIGHBOURHOOD OF STELLENBOSCH. I2y 



prospectors throughout the (Hstrict, and the possibiHty that the 

 lowest beds may hold alhivial tin. 



I have spoken of the valley Ixjttom as being flat : as a matter 

 of fact, the alknial fl(X>r is disposed in three well-marked 

 terraces, having the average elevations of lo. i(S, and 45 feet 

 respectively above present river level. The highest terrace is 

 found in the north-east corner of the Flats, where its margin 

 forms a prominent gravel ridge ( see map, Plate 3 )• 1 he second 

 terrace forms the central portion of the Flats, and its margin 

 can be traced from the mouth of Jonker's Hoek down to the 

 Football Ground, running nearly parallel to the Jonker's Hoek 

 Road and Van Riebeek Street. . The third terrace constitutes the 

 remaining, southern and western parts of the Flats : beneath this 

 terrace the river has entrenched itself to a depth of 20 feet in 

 places. 



-l-ig. 4. 



Elsewhere* I have described these terraces at some length. 

 and have tried to picture the conditions which led to the accumu- 

 lation of a thick dejxjsit of alluvium at this point in the course 

 of the river, and to the subsequent step-by-step removal of this 

 material with production of a terraced structure in the residue. 

 Briefly, the conclusions to which I was led are these : That the 

 formation of a deposit is to be ascribed to the confluence at one 

 spot of a number of torrential streams, all throwing their bur- 

 dens of sediment into Eerste River, and perhaps also to the 

 abrupt change of direction suffered by the river between the 

 points where it enters and leaves the Flats ; and that the subse- 

 quent partial removal of the deposit was induced by a general 

 elevation of this part of the country, whereby the gradient, and 

 hence the transporting power of the river were increased, and 



* '" The Terraces of Eerste River at StiHenljoseli." Tiaiis. (,'ri>l. Soc 

 of S.Afr.. 16 (1913). 147. 



