STOW — SOUTH-AFEICAN GEOLOGY. 523 



3. On some Points in South- Africait Geology. — Parts II. and III, 

 On the DwYNODOTS or Karoo PoEMATioiir — its Forest-zones, as 

 slioivn hy Sections in the Winterberg and the Stormberg (Dor- 

 drecht, Upper Kei River, and Klaas Smifs River), and its De- 

 nudation by Ice-action ; with RemarTiS on the Climatal changes 

 in South Africa. By G. W. Stow, Esq., of Queenstown, South 

 Africa. 



(Communicated, with Notes, by Prof. T. Eupert Jones, F.G-.S.) 

 [Eead December 7, 1870*.] 



Part II. — The Poeest-zones and other Strata of the Dicynodon 

 Formation. 



In the Dicynodon (Karoo) formation t we find two or more 

 distinct forest-zones in this eastern part of the colony. At Dordrecht 

 (Albert), in the Upper Stormberg range, on the south of the 

 Kaga Mountain (an offshoot of the Winterberg, in East Somerset), 

 in the Kroome range, and in the Amatola Mountains (British 

 KafPraria) a thick and gritty sandstone frequently makes its 

 appearance on the slopes of minor valleys, and on the flats at the 

 same line of elevation ; and wherever it is exposed there is almost 

 invariably an abundance of fossil wood. Near Greytown and the 

 Kabousie nearly entire trunks of trees have been discovered. Near 

 the Kom-Kom, a branch of the Kaga Biver, I have collected 

 numerous specimens J. 



Section at Dordrecht. — In the section (fig. 8) the portions marked 

 a, a, a are covered with debris. No, 1 protrudes in enormous masses 

 of greenstone or basalt (" ironstone" of the colonists), which, judging 

 from the line of exposure, must be conformable with the strata 

 on which they seem to rest §. About 50 feet below, a rather com- 

 pact sandstone is exposed, resting upon a claystone (No. 2)||, about 

 two feet thick ; this, again, upon No. 3, a coarse-grained greyish 

 sandstone ^, twelve or fourteen feet ; and immediately beneath this 

 is No. 4, grey indurated shale. Below this is a coarse friable 

 brownish sandstone (No. 5), resting on No. 6, which is very similar, 

 but full of ferruginous patches and nodules, specimens of which 

 are sent**. Many of these nodules are filled with ochres, fine im- 



* For the remainder of the papers read at this Meeting, see pp. 49-73. 



t For Mr. Stow's description of a section of the Karoo beds of the Ehenos- 

 terberg, an offshoot of the Sneewbergen, see Quart. Journ. Greol. Soc. vol. xv. 

 p. 194.— T. E. J. 



J Several segments of probably coniferous trunks were sent by the author. — 

 T. E. J. 



§ The specimen of No. 1 sent is a small exfoliating nodule of greenstone. 

 —T.E.J. 



II The specimen of No. 2 sent is a piece of felspathictrap (claystone). — T. K. J. 



5[ With felspathie cement. — T. E. J. 



** " D. S. 2." Nodules of quartz grit, with some felspar, cemented with iron- 

 oxide, showing transverse lines of stratificatiou externally, and containing ochre. 

 — T. E. J. 



