138 REPORTS ON THE STATE OF SCIENCE. 



him to rearrange his ideas for his Bulletin No. 86, and it was only after- 

 wards, when writing his memoir on the Lake Superior Iron-Ores, that 

 he broke loose from the American Survey traditions and grouped to- 

 gether in the Archaean the sedimentary iron formations of Vermilion 

 and Marquette, which he had formerly placed in the Algonkian.' 



Report by Mr. H. Kynaston. 

 Older Rocks. 



While fully admitting the desirability of securing greater uniformity 

 of geological nomenclature between the different colonies, I consider it 

 inadvisable at present to introduce names of European or American 

 groups and systems into South African geology, except for purposes of 

 comparison and correlation. These can be clearly defined in the 

 Northern Hemisphere, but are not so suitable for South African strati- 

 graphy, even if the ages were known of all the South African forma- 

 tions. For example, the Karroo System includes a practically uninter- 

 rupted succession of beds, which can be correlated with strata ranging 

 from the Carboniferous to the Jurassic. 



With regard to the term Archaean, there is not so much objection to 

 this as there is at present to the use of such strictly defined terms as 

 Palaeozoic, Mesozoic, &c, provided it is employed in its wide sense. 

 If so used, it might provisionally include all rocks older than the Wit- 

 watersrand System — i.e., the older granites, the Swaziland sedimentary 

 beds (Moodie's series in the Eastern Transvaal and Kraaipan formation 

 in the West and Bechuanaland Protectorate), and the basal gneissic and 

 schistose complex. It would be unwise to include the Witwatersrand 

 System also in the Archaean, as we do not yet know whether this may 

 not correspond to part of the early Palaeozoic. 



Ventersdorp System. 

 The rocks included in this system have not yet been properly sur- 

 veyed or classified in the Transvaal, but they should certainly rank as a 

 separate system, since there is a marked break both above and below 

 them, and they include sedimentary as well as volcanic rocks, both in 

 the Transvaal and Cape Colony (Bechuanaland and Griqualand West). 

 In the north of the latter colony they have been subdivided into three 

 series, which are probably also developed in the western Transvaal. 



Transvaal System. 

 We consider this to be a suitable term, which should be retained, 

 especially since it is now generally in use in South African geological 

 literature, for the Black Eeef, Dolomite, and Pretoria series, the equiva- 

 lents of which in northern Cape Colony are as follows, in descending 

 order: — - 



Pretoria series . , Griqua Town series. 



[The Ongeluk volcanic series, or Middle Griqua 

 Town beds of Rogers, are probably represented 

 by the basie amygdaloidal lavas in the middle 

 ",'..■-■ of the Pretoria series.] 



Dolomite series . . Dolomitie limestones of 1 . ,, n , 

 Black Reef series . , Basal quartzes pf I Campbell Rand series. 



