332 Reports & Proceedings — Geological Society of London, 



a rather large proportion of gneissic and schistose rocks, olivine- 

 basalts, etc., in this case presumably of Scottish origin. A comparison 

 with a similar bed on the Northumbrian coast, studied by Dr. J. A. 

 Smyth, is made. 



The main Drifts of South-East Durham are briefly described, 

 more especially in relation to the limits and direction of flow of 

 that part of the ice-stream which carried Cheviot material in the last 

 phase of the maximum glaciation of the east coast. The direct 

 southerly or south-westerly movement of this ice towards th& 

 northern face of the Cleveland Hills at this period is indicated by 

 striae, by the western limits of Cheviot material in this area and in 

 Northumberland, and by the superficial mingling in the lower Tee& 

 Valley of the products of this ice with material brought at an 

 earlier period over Stainmoor. ^ 



The occurrence of Shap Granite and olivine-basalt erratics is 

 indicated on an accompanying map. 



The conspicuous kaimes developed about the village of Sheraton 

 and others, associated with the Cheviot Drift, are described. A few 

 remarks are added on a deserted watercourse at Ferry hill, and on 

 the question of post-Glacial erosion. 



2. "On the Eelationship of the Yredefort Granite to the 

 Witwatersrand System." By Frederick Willoughby Penny, B.Sc.,. 

 F.G.S. 



The Vredefort Granite has always been considered as a member 

 of that ' old granite ' group, which everywhere in the Transvaal and 

 in the Orange Free State is found emerging from beneath the 

 Witwatersrand Series. 



The relationship of this ' old granite ' group to the overlying 

 rocks has been the theme of frequent discussion. The Vredefort 

 area was made the subject of a paper in 1903 by Dr. G. A. F. 

 Molengraaff, who proved to his own satisfaction the intrusive nature 

 of the granite into the encircling sediments. In the following year, 

 however, when work in other areas indicated the probability that 

 there the ' old granite ' group formed the floor on which the 

 Witwatersrand Beds were laid down, l)r, Molengraafi' practically 

 withdrew his previous deductions regarding the Vredefort area. 



In the present paper evidence is brought forward to prove clearly 

 the intrusive character of the Vredefort Granite, not only into the- 

 Witwatersrand Beds, but also into the basic intrusion associated 

 with them, based on an examination of the adjacent rocks and 

 a detailed map of several miles along its contact on the north-east 

 side of the granitic boss in the Orange Free State. It is shown 

 that along its margin the granite has removed, possibly by absorption, 

 but more probably by ' underhand stoping ', varying amounts of 

 the sediments from point to point ; that it has reacted with the basic 

 intrusions in the sedimentary beds, with the consequent production 

 of hybrid rocks ; that, in one place, a subsidiary intrusion of granite 

 occurs in the middle of the diabase ; and, finally, that the granite, 

 where it comes into contact with the slate members of the 

 Witwatersrand Series, has induced a definite type of metamorphism 



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