538 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



table-tops of such mountains * as the Winterberg, the Groot Tafel- 

 berg, the Twee Tafelbergen, Houder Neck, the Mostert Hoek moun- 

 tains, and Hangklip, near Queenstown, are the evident monuments) 

 to the excavation of the deepest valleys in the existing flats. 



Whether or not all these Karoo strata were deposited under a uni- 

 form climate it is difficult to prove ; but that there was some differ- 

 ence between the climate of the Dicynodon period and the present 

 seems to be indicated by the section (fig. 8) of the Upper Stormberg, 

 exposed near Dordrecht. These strata are now about 5000 feet 

 above the level of the sea. One bed, 10 feet thick, is composed of 

 a fine conglomerate of small fragments of quartz, and can be traced 

 wherever the side of the mountain is sufficiently bare. The only 

 locality, at present known, whence such quantities of quartz could 

 be derived is the Washbank. Immediately above and below this 

 band of conglomerate is a coarse gritty sandstone. The one above 

 is of a yellowish ochre colour, containing coarse nodules, such as 

 Nos. D. S. 2 (D. S. 1 is a specimen of the quartz-grit) ; in many 

 places it is discoloured with ferruginous patches. The one below is 

 the zone of fossil wood, which is found in abundance, evidently the 

 remains of a primaeval forest. In some places there are trunks of 

 trees between 20 and 30 feet long, and great numbers of segments 

 erect in the position in which they grew ; these latter are often 

 more than 8 or 9 feet in circumference. The fossil wood is found 

 wherever this coarse sandstone makes its appearance. The speci- 

 mens that have been examined are pronounced to belong to the 

 Coniferse. These last-mentioned strata are amongst some of the 

 latest of the Stormberg formation ; and the wide-spread remains of 

 coniferous forests found there seem to point to climatal conditions diffe- 

 rent from the present, and still more different from those of the old 

 Carboniferous formations of Europe and elsewhere, the plentiful re- 

 mains of coniferous trees here most probably indicating that such 

 forests flourished in a more temperate climate. In such a climate 

 and in deposits formed under such circumstances it is not probable 

 that such abundant coal-measures would be found as those accumu- 

 lated in the northern hemisphere. From the wide extent of this 

 fossil wood it is evident that immense tracts of forest must have ex- 

 isted in those ancient times ; but from that time to the present an 

 interval has intervened of incalculable duration, during portions of 

 which agencies (yet to be explained) have been in operation that 

 have not only occasioned the denudation above referred to, but have 

 also rendered the country a treeless region. Trees introduced by 

 human agency thrive well ; and it is not, therefore, the present cli- 

 mate that has caused the annihilation of forests : we must look to a 

 remote period for an explanation of this as well as the other pe- 

 culiar features of the country. 



Denudation of the Karoo Beds. — The encroachment and retreat of 



the sea cannot have effected the vast denudation, either during the 



subsidence or the upheaval of the land ; for there is no evidence that 



any of the strata, except those on the immediate sea-coast, have 



* These are all mountains of denudation and not of elevation. 



