THE CAPE SYSTEM 151 



The marine fossils that occur in the lower half of the 

 Bokkeveld series afford sufficient evidence that the rocks 

 in which they are embedded were deposited under the 

 sea ; and the frequent occurrence of false-bedding in the 

 sandstones throughout the series points to deposition in 

 shallow water. The bottom of the sea must have been 

 slowly sinking to allow such an accumulation of shallow 

 water sediments, although some of the shales may have 

 been formed in deeper water. In the upper part of the 

 Bokkeveld series no marine forms have been noticed ; a 

 few indistinct plants are the only fossils that have been 

 found in them. It is difficult to explain the absence 

 of marine animals if the conditions under which these 

 rocks were formed remained the same as before ; and 

 the absence of marine fossils from the succeeding 

 2,500 feet of the Witteberg sandstones and shales war- 

 rants the supposition that the conditions which pre- 

 vailed in the area now called Cape Colony during early 

 Bokkeveld times changed from marine to fluviatile or 

 lacustrine after the deposition of the third shale group, 

 and remained so throughout the later Bokkeveld and 

 the whole of the Witteberg periods. 



The following is a list of fossils obtained from the 

 Bokkeveld beds : 



