14 DISCOVERY REPORTS 



altered and crushed sediments, which might well have compared, in their original state, 

 with the Burdwood Bank shale. No Foraminifera were, according to Dr Tyrrell, ob- 

 served in the sections in which the Radiolaria were found. Treatment of the material by 

 disintegrating it in an iron mortar likewise unfortunately yielded me no trace of 

 Foraminifera. 



Tertiary strata are found following the Senonian in both Patagonia (cf. Wilckens, 

 loc. cit.) and in Graham Land (cf. Andersson, loc. cit.). They often contain marine 

 fossils and are said to extend in age from the Eocene to the Pliocene. In Patagonia they 

 are known as the Pyrotherium-Notostylops Beds (Eocene and OUgocene, largely ter- 

 restrial but partly marine), Patagonian Molasse (Lower Miocene, marine), Santa Cruz 

 Beds (Middle and Upper Miocene, largely terrestrial), and Parana Beds (Pliocene, 

 marine). In Graham Land the tertiaries appear conformably to follow the Upper 

 Cretaceous in Seymour Island, and contain what is recorded as an Upper Oligocene 

 or Lower Miocene assemblage of MoUusca ; many of the forms are the same as those of 

 the Patagonian Molasse. Von I bring, however {loc. cit., p. 387), states that the flora 

 recorded from there by Oliver as Oligocene is really of Palaeocene age. The ? Pliocene 

 Pecten-congXomtraXQ is a much later deposit which rests unconformably on the older 

 strata; Andersson {loc. cit., p. 52) compares it with the Patagonian Parana Beds. 



The whole succession of Upper Cretaceous and Tertiary strata in the South Patagonia- 

 Graham Land region may thus be compared, for instance, with that of Trinidad. 



CONCLUSION 



Hitherto the geological evidence from the Burdwood Bank appears to have been 

 confined to the two soundings by Ross referred to by Suess,^ which yielded volcanic 

 rocks in lat. 54° 18' S, long. 60° W, and in lat. 54° 41' S, long. 55° 12' W. The present 

 evidence of sedimentary strata is therefore of considerable geological interest. 



Although there appears to be some doubt, as shown above, on the degree of reliance 

 that may here be placed on certain species of Foraminifera generally taken to be precise 

 Upper Cretaceous markers, in my opinion there is httle doubt that, on the ground of 

 the foraminiferal evidence, the Burdwood Bank beds include Upper Cretaceous (Sen- 

 onian) strata, together with representatives of the Lower Tertiary succession. In the 

 circumstances, and on account of the rather deep-water facies of the Foraminifera, 

 it is perhaps not a matter for surprise that faunas of the two ages cannot be clearly 

 separated. 



The Burdwood Bank beds thus appear clearly as a direct continuation of those of 

 Staten Island and Tierra del Fuego, as was believed by Suess. The latter beds are seen 

 to have taken part in the continuation of the Andean folding, which has been discussed 

 by authors under the ill-named title of the "South Antillean Arc"; Mr Wordie has 

 agreed that it may better be referred to as the "Scotia Arc", since it surrounds the 

 newly named Scotia Sea. This new evidence appears to strengthen the hypothesis that 



1 The Face of the Earth (English Trans.), 1909, iv, p. 490. 



