282 GEOLOGY OF THE TABLE-LAND. 



crustation is recent, we observe the woody texture contained 

 in a solid case, and without any remarkable alteration ; but 

 in proportion as the calcareous envelope increases, the 

 wood becomes disorganized, and changes ijisensibly into a 

 dry and black powder." From this state he supposes the 

 centre gradually to increase in solidity till the whole mass 

 becomes a mere sandstone, and nothing but an arborescent 

 form indicates the ancient state of vegetation. 



The incrustations near Simon's Town are of a similar na- 

 ture to those found in New-Holland, because, says Dr. 

 Abel, the descriptions of authors correspond with the ap- 

 pearances I have witnessed, and because I have compared 

 a specimen brought from Bald Head in New-Holland, by Mr. 

 Brown, with those I obtained at the Cape, and can trace 

 no essential difference, either in the external characters or 

 chemical composition. It follows from this statement, that 

 Flinders and Vancouver have confounded vegetable in- 

 crustations with true corals ; and hence the reasoning on 

 their supposed submarine origin, and modern rising of the 

 Bald Head, &c. above the level of the ocean, is incorrect. 



Geology of the North and South, and East and West 

 Ranges of Mountains. — The ranges of mountains which 

 run northward from the Cape Peninsula to Orange or Ga- 

 riep River, in the points where examined, exhibited granite 

 and slate, with vast deposites of sandstone or quartz rock 

 with numerous table-shaped summits, — thus showing a 

 similarity of composition in these mountains to those of the 

 Cape Peninsula. 



The three great ranges of mountains that run from east 

 to west, according to the reports of travellers, are of the 

 same general nature, and eminently characterized by the 

 vast abundance of sandstone reposing in horizental strata 

 upon the granite and slate, forming the middle, and very 

 often the higher parts of the chains. 



Geology of the Table-land. — From the third range on- 

 wards to lat. 30^ S., the prevailing rock in the plains and 

 hills is sandstone. At Dwaal River, the frontier of the 

 colony, there are rocks of augite-greenstone and basalt, 

 probably in veins traversing the sandstone. Rocks of the 

 same description, disposed in beautiful globular concretions 

 (not boulders, as stated by Burchell), occur near to Kaabes 

 Kraal, 29° S. lat., probably in veins traversing the horizon- 

 tal sandstone of that district. The Karreebergen, or Dry 



