536 PKOCEEDINGS OP THE GEOLOGICAL SOCIEXT. 



the mountains, but may have even constituted unknown thicknesses 

 above their present tops. 



"With regard to the rocks themselves, of which these mountain- 

 ranges are composed, much is yet to be learnt, and to arrive at a 

 satisfactory conclusion about them wUl yet be the life-study of some 

 future geologist. Many questions of great interest and importance 

 have yet to be answered, thus : — Were these strata really of lacus- 

 trine origin? and if so, were these extensive and thick deposits 

 formed during a subsidence ? If so, what were the outer barriers of 

 such wide-spread "lacustrine" deposits, effectually cutting off ail 

 communication with the ocean during the deposition of sediments, 

 it is said, of some 6000 feet ? Or were they laid down when the 

 region was considerably above the level of the sea ? The Dicynodon 

 formation is cut across by the oblique sea-coast near the Gualana 

 River, and extends northward thence into Natal; its boundary 

 therefore on the south-east has disappeared in the present ocean. 



Proceeding from the sea inland, through Albany, the country 

 rises in a succession of vast steps, as shown in the outline-section, 

 fig. 13. 



The most recent of the Karoo deposits are to be found in the 

 Stormberg* ; and the whole face of this range (as is plainly seen on 

 approaching it) is composed of horizontal strata. Here, again, 

 the question arises, What could have formed the boundary of a 

 formation that shows so little evidence of displacement as the ele- 

 vated strata of these mountains? Again, Do these constitute one 

 continuous formation? Were they the vast deposits of a single 

 lake, or, rather, of many successive lakes ? It is probable that, on a 

 closer examination, the latter will prove to be the case, and that 

 this extensive series of strata may be divisible into several limited 

 and overlapping groups of deposits. To explain this, I have sent a 

 section (fig. 14) of that part of the formation to which this paper 

 principally refers. The synclinal structure indicates that one basin 

 must have extended from the neighbourhood of the Katberg on the 

 south to near the Washbank on the north. Thus the dip of the 

 strata of theQueenstown hills is from 5° to 6°, and at the Bongolo Neck 

 5° N.K. W. ; on an offshoot of the Stormberg, near the Buffel-Doorns 

 Flat, 5° N.N.E. ; at the foot of the Stormberg 4° to 5° K.N.E.; while 

 at Dordrecht, on the other side of the mountains, at one spot the 

 dip is 4° to 5° S.E,, at another 6° to 7° in the same direction, and 

 some twelve miles nearer the Washbank it is 5° to 6^ S.S.E. These 

 dips seem to prove this particular basin to have its synclinal axis 

 somewhere about the centre of the Stormberg range, and that, 

 sliould the strata be continuous, the deposit must be of enormous 

 thickness. 



Not only must the period of deposition of such rocks have been 

 of immense duration, but so also miist that of their denudation, 

 from the time of the breaking of the original plateau f (of which the 



* Quart. Journ. Geol. Soc. vol. xxiii. pp. 143 and 172. — T. K. J. 

 t Such a plateau must have been similar to that in Dr. Livingstone's ideal 

 section of South Central Africa. 



