i6 DISCOVERY REPORTS 



of the area are reviewed, and the regional stratigraphy is discussed. It is considered that 

 the Burdwood Bank beds are clearly shown to be the continuation of those exposed on 

 Tierra del Fuego and Staten Island, and a part of the (renamed) Scotia Arc of folding, 

 which is continued on a trend precisely determined by the soundings to lie on the line 

 of the Shag Rocks, South Georgia, Gierke Rocks, South Sandwich Islands, South 

 Orkney Islands to the South Shetlands and Graham Land. 



Note. Pebbles from Sts. 719 and 720 were submitted to Mr W. Campbell Smith 

 for his opinion, and he kindly reports that in the sample from St. 719 he found a 

 large number of dark brown (some almost black) pebbles rich in phosphate and 

 containing fragments of Radiolaria. Most of these are slightly calcareous as well as 

 phosphatic, and are rather like the phosphate nodules of Agulhas Bank preserved in 

 the British Museum (Natural History). 



In the sample from St. 720 he found similar phosphatic nodules, and also rounded 

 pebbles of greywacke, quartz-plagioclase-porphyry (quartz-porphyrite of some authors), 

 quartz-diorite, quartz-gabbro, hornblende-granulite, and a slaty rock with bands rich 

 in clastic felspar. Such rocks must have been derived from a land mass. The "slate", 

 "greywacke", quartz-diorite, and quartz-plagioclase-porphyry can be matched almost 

 exactly with rocks from points on the west of Tierra del Fuego, e.g. a similar quartz- 

 diorite occurs on Hermite Island. He found no fragments of volcanic rocks in either 

 sample. 



