Beeh;/ Thompson — Trias in South Staffordshire. 213 



gold-mining industi-y overthrusts will prove by counteracting tbe 

 effects of this secondary steepening, is at once apparent. 



In the group of rocks succeeding the Witwatersrand Beds 

 Dr. Molengraaff finds a fancied resemblance to the sequence from 

 the Table Mountain Sandstone and succeeding beds ; the Black Eeef 

 Series, Dolomitic Series, and Pretoria Series being compared by him 

 with the Table Mountain Sandstone, Bokkeveld Beds, and Witteberg 

 Series. The dolomite in the Transvaal is unfossiliferous, while the 

 Bokkeveld Beds contain a rich fauna of a Devonian facies. The 

 dolomite most resembling that in the Transvaal is the rock in the 

 Cango district, where, as previously stated, it is probably in an 

 inferior position to the Table Mountain Sandstone. In Cape Colony 

 the Witteberg Beds pass up conformably into the Dwyka Con- 

 glomerate ; in the Transvaal the Glacial Conglomerate is markedly 

 unconformable to the Pretoria Series. The resemblance, therefore, 

 between the two colonies does not seem very exact. Eegarding the 

 unfossiliferous nature of the Transvaal older rocks, and the move- 

 ments to which they have been subjected, it seems futile to attempt 

 a correlation with the undetermined succession at the Cape ; while 

 to draw a.ny comparison with the European Palseozoic rocks, as is 

 frequently done, is a fortiori valueless deductive reasoning. 



Of the older rocks of Rhodesia, Zululand, and Natal the information 

 is scanty. It appears that the Bokkeveld Beds, or at any rate strata 

 containing the Bokkeveld fossils, die out before they reach Natal, 

 just as they do in the north-west provinces of Cape Colony. A fact 

 in favour of their being unrepresented in the Transvaal. 



To briefly summarize the knowledge of the older stratified formations 

 in South Africa. The geological record is very imperfect. There 

 are many rock groups, but excepting the Bokkeveld Beds at the Cape 

 their age has not been determined. There are no certain repre- 

 sentatives of strata of Silurian, Ordovician, and Cambrian ages. 

 South Africa, then, appears to be the relic of an ancient massif 

 composed of Arch^an rocks, into which are sunk, in the form of 

 complex anticlines and synclines, several rock groups of undetermined 

 ages, which exist at the pi'esent day as lofty mountain ranges or as 

 high plateaux, enclosing the western portion of the Indo-African 

 basin in which the Karroo deposits were laid down. 



Note. — A Graptolite, Bijolograptus pristis, is stated to have been 

 found in the slates of De Kaap, but this discovei'y has not been 

 confirmed. (Trans. Geol. Soc. South Africa, 1896, vol. i, p. 52.) 



V. — Some Trias Sections in South Staffordshire. 



By Beeby Thompson, F.C.S., F.G.S. 



4 N occasional visit to a village on the western border of South 

 j\_ Staffordshire has given me the opportunity of studying the 

 Triassic deposits around there. Possibh'^ the various sections I have 

 visited are well known to local geologists, although, so far, I have 

 not come across any description of them. One section in particular, 

 I think, must have been overlooked, and this it is now proposed to 



