434 



W. M. DAVIS OBSERVATIONS IN SOUTH AFRICA 



cycle. The features just mentioned were seen during an excursion undei 

 the direction of Mr A. L. Hall, of the Transvaal Geological Survey, from 

 Johannesburg to the Duivels Kantoor and back, by the railway line be- 

 tween Pretoria and Delagoa bay. The Duivels Kantoor, or Devil's shop, 

 is a promontory in the bold escarpment by which the highlands are here 

 terminated eastward; it lies a few miles south of the deep valley of the 

 Elands river and is reached by a wagon road from Godwan station. 

 From its edge one overlooks the lower land, which is elaborately dissected 

 in deep weathered granite and in which Barberton lies. A general idea 

 of the form of the escarpment is given in figure 11, looking southward. 

 The determining stratum is the Black Beef quartzite, dipping gently 



Figure 11. — View Southward along the Escarpment of Black Reef Quartzite overlying 



Granite. 



The view is as seen from the Duivels Kantoor, in the northeastern part of the Transvaal. 



westward, and here much thicker than where we saw it between Johannes- 

 burg and Vereeniging. The overlying dolomite is worn into rounded 

 hills next farther west; then comes another escarpment of somewhat 

 greater altitude, but of less pronounced form, determined by certain re- 

 sistant quartzites of the Pretoria (or Potchefstroom) system; and thus 

 the full altitude of the High Veld is reached. A part of this higher 

 escarpment is shown on the right in figure 11. Where Elands river flows 

 eastward across these west-dipping quartzites, there are two waterfalls, 

 and here the grade of the railway is so heavy from Waterval Boven to 

 Waterval Onden (Above the Falls to Below the Falls) that a toothed 

 strip is added between the rails, into which a cogwheel under the engine 

 fits. Some members of our party made frequent mention of certain sup- 

 posed faults by which the descent from the interior highland to the ocean 

 on the east is supposed to have been effected; but when the profile of the 



