The Forming of the Drakensberg. 63 



In the Cave sandstone on Lelie Kloof, near Jamestown, Dunn 

 records the occurrence of slabs, showing sun-cracks and the tracks 

 of (?) crustaceans. At Morija, in Basutoland, according to Mr. 

 Dornan, of that place, there are numerous footprints of dinosaurs in 

 the sandstone, while he states that such are also found at 

 Harrismith. The discovery of crocodilian remains in the sandstone 

 in Barkly East is also significant. 



The occurrence in a few places of thin bands of blue-black shale 

 in the sandstone, full of remains of cstheria and other crustaceans, 

 perhaps indicates, as has been mentioned already, the slightly 

 brackish character of the water. The extensive false bedding often 

 met with in the lower portion of the sandstone shows that there 

 were strong currents in the lake ; later on, these ceased, as is 

 indicated by the uniform bedding in the upper portion. 



While the lake silted up there were small movements in the 

 earth's crust which heralded the great volcanic eruptions of the 

 Drakensberg. In many places the bed of the lake rose above tide 

 level and a portion of the material was eroded, and sometimes the 

 entire bed of sandstone has thus disappeared. At several places 

 earthquakes fractured the strata, and some of the gashes produced 

 were filled in with soft sand, now forming irregular dykes through 

 the Ked beds. 



Such were the physical conditions just before the commencement 

 of the volcanic outbursts ; a great vlei — if one may so term it — several 

 hundred miles in diameter, with brackish water covering a sandy 

 bottom. This vlei was studded with muddy flats and islets, over 

 which wandered dinosaurs and crocodiles in search of their prey. 



IV. — Volcanic Activity in the Drakensberg. 



The sedimentary rocks of the Drakensberg are penetrated by a 

 large number of volcanic necks, from which immense quantities of 

 lava, and occasionally volcanic ash, were erupted. Since Mr. 

 Schwarz's discovery of nineteen necks in Griqualand East, over 

 eighty additional vents have been recorded within a radius of about 

 fifty miles of Barkly East. 



This by no means represents the total number occurring in that 

 area, for there must be many vents which are buried beneath great 

 piles of lavas and not yet exposed by denudation. 



When it is considered that the hundred volcanoes now known are 

 all situated within an area of a little over 5,000 square miles, we get 

 an idea of the immense number which still remain to be discovered 

 in the Colony, Basutoland, and elsewhere. The volcanic necks are 



