198 DISCOVERY REPORTS 



a patch of 750 square miles of medium sand of group E midway between the northern 

 and southern extremities. 



THE FINE SAND GROUNDS 

 The fine sand grounds of the southern and western parts of the region examined 

 cover an area of about 106,500 square miles and carry deposits of all the groups 

 recognized. Deposits of group A occur off the west of West Falkland Island, of group F 

 north of this and in deeper water west and south of the Falkland Islands and the 

 Burdwood Bank, and off the coast north of Point Santa Cruz. Between lat. 47 30' and 

 48° 30' S deposits of type C occupy the continental shelf between long. 6i° and 64 40' W. 

 This group appears again a little to the south-west on the continental shelf nearer the 

 coast between long. 63 and 67 W and lat. 49 and 50 10' S. A further area covered by 

 deposits of group C lies on the continental shelf east of the Strait of Magellan and Tierra 

 del Fuego east of lat. 65° W. Its eastern boundary coincides with that of the grounds 

 of coarser texture on the edge of deeper water as described below. Deposits of group D 

 occupy a central area on the continental shelf between lat. 48 30' and 50 S, and also 

 the area of fine sand grounds between lat. 50 10' and 52 10' S and long. 63 20' and 

 68° W. Deposits of group E occur in a coastal belt between Point Santa Cruz and the 

 entrance of the Strait of Magellan, and on the western slope of the Burdwood Bank. 

 The area to the west of the Falkland Islands and the continental slope to the south of 

 them is covered by deposits of group B. 



COARSER GROUNDS WITHIN THE FINE SAND GROUNDS 

 The find sand grounds are interrupted by many coarser grounds. North-east of the 

 Falkland Islands they are separated from the silt grounds by a ground of coarse gravel 

 about 1360 square miles in area on the continental shelf, from which a ground of 

 medium sand about 400 square miles in area extends down the continental slope into 

 the fine sand ground. The deposits of both these grounds are of group A. 



A coarser ground about 5600 square miles in area, extending eastwards from Cape 

 Tres Puntas as far as long. 64 40' W and southwards as far as lat. 49 S, consists of 

 various grades of gravel. Off Cape Tres Puntas an area of about 1100 square miles 

 consists of medium gravel of group D. It adjoins an area of 950 square miles of fine 

 gravel off Point Deseado. Off Nodales Bay lies an area of about 850 square miles of 

 very coarse gravel, south of which lies an area of about 2300 square miles of coarse 

 gravel. The coastal portions of the last three grounds consist of deposits of group F, 

 while in the outer parts the deposits belong to group C, as do those of an area of about 

 470 square miles of medium gravel lying at the south-eastern extremity of these grounds 

 of coarser grade. 



A little more than half-way between the last grounds and the edge of the continental 

 shelf lies a ground of finer texture. It extends in approximately a north-westerly and 

 south-easterly direction between lat. 48 and 49 10' S, and is about 2250 square miles 

 in area. The northern fourth of it, 470 square miles in area, consists of medium sand of 

 group C, the second fourth of about 560 square miles of fine gravel of group D, the 



