454 Annals of the South African Museum. 



described the geology of the N.W. Zoutpansberg District in a Memoir 

 of the Transvaal Geological Survey. He found that the Bushveld 

 Sandstone series is especially conspicuous along the Limpopo Valley 

 in the neighbourhood of Rhodes' Drift, from which point it extends 

 east and west for many miles, forming prominent ridges rising "200 

 to 300 feet above the river. The sandstones vary in colour from red 

 to yellowish white, are fine-grained, even in texture and sharp to 

 the touch. They are usually extremely massive and frequently re- 

 presented by a single bed from 30 ft. to 50 ft, in thickness without 

 divisional planes. Occasionally, however, false-bedding on a very 

 large scale traversing the full thickness of the rock and dipping at 

 angles as high as 20 degrees is brought out by weathering. 



Below the upper and harder portion of the massive sandstone and 

 grading upwards into them there is almost invariably found about 

 15 20 ft. of sandy or marly mudstones, usually light green to purplish 

 in colour, which contain numerous concretionary masses of limestone, 

 varving from an inch to 2 or 3 feet in diameter. This lower marlv 



\j O * 



portion of the sandstones usually weathers out into caves. Downwards 

 the marly rock passes into red or purple sandy shales and soft sand- 

 stones, calcareous in places, and frequently mottled with light green 

 patches. The average thickness of this lower series is about 200 feet. 



"Where the sandstones form very prominent ridges and kopjes they 

 are frequently found to have been much hardened by secondary 

 silica, usually deposited along the numerous joint planes. In some 

 cases the joint planes and fractures are so numerous that the whole 

 rock becomes a breccia." 



Dinosaur remains have been discovered in these beds. On the 

 farm "Wiepe 1258, Mr. Bowker found a number of bones which 

 were described by Broom as Gryponyx transvaalensis. 



In the west of the Waterberg Division of the Transvaal Bushveld 

 Sandstones occur in the area between the Limpopo and its tributary 

 the Pongola and apparently extend a little way across the river into 

 the Bechnanaland Protectorate. According to information supplied 

 by Dr. du Toit the sandstone rests on Coal Measures which them- 

 selves lie unconformably on Waterberg Beds or the Old Granite; 

 and Nelson's Kop is capped with a volcanic flow. The Nelson's 

 Kop sandstone - - more fully described later - is an approximation 

 to the Forest Sandstone type. 



Dr. du Toit has recently presented to the South African Museum 

 a few bones which he obtained from the beds at Slypsteen Drift 

 on the Limpopo. They are, unfortunately, unrecognisable specifically, 

 consisting of isolated phalanges and a portion of a caudal vertebra. 



