128 REPORTS ON THE STATE OP SCIENCE. ^ . 



2. Potchefstroom or Transvaal System. 



l?or the rocks overlying the amygdaloids there is again a choice be- 

 tween two terms, and this question mainly concerns the geologists of 

 the Transvaal. 



The name Transvaal System is supported by eight votes, against 

 three for the name Potchefstroom System, so that in this case there is 

 a strong majority of the Committee in favour of the adoption of the 

 older name, the Transvaal System. As the rocks are widely distributed 

 in the Transvaal, and as they give rise to some of the most characteristic 

 features in the State, the name is perhaps not unsuitable. The name 

 Potchefstroom has the advantage of fixing a more precise type 

 locality. There are certainly great disadvantages in the use of the name 

 of a State as that of a geological system, for the ambiguity (some Trans- 

 vaal rocks not being Transvaal rocks) must frequently be inconvenient. 

 Hence the term Potchefstroom System would probably occasion less 

 inconvenience, but the choice between these two terms will, no doubt, 

 be settled by the practice of geologists in the Transvaal. 



3. The Waterberg System. 



The last of the proposed systems for pre-Karroo rocks is that for the 

 Waterberg sandstone. There is practical unanimity that these rocks 

 should be regarded as a distinct system and called the Waterberg 

 System. 



The age of the amygdaloids, the Transvaal and Waterberg Systems, 

 is unquestionably doubtful. The Waterberg System lies unconform- 

 ably upon the Transvaal System, and that is unconformable upon the 

 amygdaloids, which are in turn unconformable upon the Witwatersrand 

 System. None of the rocks contains fossils. The Waterberg System 

 is, however, regarded with much plausibility as the inland representa- 

 tive of the Cape System, and the Cango beds of the southern part of 

 Cape Colony may represent the Transvaal System. If so, then the 

 Waterberg System would be Devonian, the Transvaal System and the 

 Vaal River, or Ventersdorp amygdaloids be Lower Palaeozoic (Silurian, 

 Ordovician, or Cambrian). 



III. The Karroo System. 



The classification of the Marine Devonian beds does not involve 

 much inter-State difference of opinion, as the marine beds occur only 

 in Cape Colony and Natal. The Karroo System is of wider extent, but 

 there is less disagreement and overlapping in nomenclatures than with 

 the unfossiliferous pre-Devonians. The classification recommended 

 by the geologists of Cape Colony is as follows : — 



Karroo System 



( T>rakensbcrg beds. 



„, , c . J Cave sandstone. 



Stormberg Scries . Red bcds . 



VMoltcno beds 



s. 



Beaufort Series 

 Dvvyka Series 



