STOW SOTTTH-AFRICAN GEOLOGY. 497 



2. On some Points in South-Ajfrican Geology. By Geoege 

 William Stow, Esq., of Queenstown, South Africa. — Part I. 



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



[ReadNoT. 23, 1870*.] 



I. On some of the Formations of Port Elizabeth and its neighbourhood. 

 § 1. The Jurassic Formations (pp. 497-614). 

 I 2. The Posttertiary Formations (pp. 615-622). 

 II. On the Dicynodon-Formation ; its Forest-zones and other strata (pp. 



623-634). 

 III. The Chmatal Changes of South Afi'iea, as indicated by its Geology and 

 Fossils ; and especially the Glacial Denudation of the Karoo Strata 

 (pp. 634-546). 

 Appendix. 



Part I. — § 1. The Jurassic Formations. 



Introduction. — Whatever advances geology has made during the 

 last twenty-five years in South Africa (with which the names of 

 Bain, Atherstone, and Bubidge will be ever connected), it must be 

 confessed that we are but mere students in the elementary portion 

 of this part of the great " stone book of nature ; " and it may be 

 expected that every new investigation will bring to Kght facts, and 

 lead to conclusions, of which at present we have but a feeble and 

 imperfect notion. 



To the present time geological knowledge in South Africa has 

 progressed but slowly. The great broad outlines of the geology of 

 the country have been traced by those whose names have been men- 

 tioned ; but the minutiae have yet to be filled up. The South- 

 African explorer labours under many serious disadvantages, not only 

 from the horizontal position of many of the strata, but from the 

 want (with the exception of a few mountain-passes) of great road- 

 cuttings, and from the absence of mining operations, so that he has 

 to depend upon the escarpments found along the river-valleys and 

 mountain-sides, leaving large intervening tracts that must still re- 

 main in some degree of uncertainty until opportunities shall arise 

 for their more definite examination. 



With regard to the fossiliferous strata in the neighbourhood of 

 Port Elizabeth, and of the Zwartkops and Sundays Rivers, for a long 

 time I had felt that too much had been done in the way of curi- 

 osity-hunting, by mixing and generalizing all the fossils of what 

 has been termed the " Uitenhage Formation," from whatever part 

 of it they may have come ; thus shells from the upper and lower 

 parts of the Zwartkops Biver have been massed together, as well 

 as those from the Upper and Lower Sundays Biver, although many 

 miles intervene between the different localities — a plan that can only 

 lead to a confused idea of the different strata ; and I felt certain that 

 this was one of the causes that prevented just conclusions being- 

 arrived at with regard to the formation in question. 



As a commencement towards getting more perfect results, I sepa- 



* For the other papers read at this meeting see pp. 29-33. 

 VOL. XXVn. PARI I. 2m. 



