OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 679 



with a green, blue, or brown tone in different samples ; when dried, the colour is, as a 

 rule, much lighter, being a pale grey or dirty white. 



Physical Characters. — The majority of the glacial deposits from the Weddell Sea 

 south of 60° S., are distinctly clay-like in character, being coherent, tough, unctuous 

 to the touch (although always containing more or less gritty particles), and requiring 

 a considerable amount of rubbing to break them down into their component parts for 

 microscopic examination. The deep-water deposits never had any smell of HgS when 

 brought up, but some of the muds from the shallow water of the enclosed bays of the 

 S. Orkneys had. When dried, these deep-sea glacial clays become hard ; they take a 

 lustrous polish when rubbed on the finger and leave a shiny streak on porcelain. The 

 tongue readily adheres to a piece of the dried clay, and there is a distinct clayey 

 odour when the mass is breathed upon. The clayey character is, as a general rule, 

 more pronounced the further one is away from the Antarctic continent. 



This is so striking that in a former report [Scot. Geog. Mag., Aug. 1905) I 

 distinguished a group of these as approximating to Ked clays in some of their 

 characteristics. As one approaches the continent and the seaward edge of the inland 

 ice, the clayey character becomes less marked, the deposits becoming rather muds, but 

 even within a few miles of the ice-barrier, as at 72° 18' S., 17° 59' W., 1131 fathoms 

 (No. 33), there is still so much of the clayey character present that the deposit can 

 only be described as clayey mud. 



In the samples from between 61° and 66° S., almost due south of the S. Orkneys, 

 there seems to be a rather erratic variation in the "mud-clay" distribution: No. 16 

 (from 65° 29' S., 44° 06' W., 2500 fathoms) being noted as the most clayey met with 

 up till that time; No. 17 (from less than a degree to the north, 2485 fathoms) is a 

 mud with very little clayey character; No. 19 (from 63° 51' S., 41° 50' AV., 2550 

 fathoms) is again a tough clay; No. 20 a mud; and No. 21 (from 62° 10' S., 41° 20' 

 W., 1775 fathoms) a muddy sand. The explanation of this irregular distribution is 

 not quite clear ; probably it is connected with the drift of the icebergs out of the 

 Weddell Sea in its western portion, and may indicate proximity to land in the 

 neighbourhood of 66° S., 48° W., where Morrell in 1823 and Ross in 1843 reported 

 "appearance of land." No. 21 seems to be too far away from the S. Orkneys to have 

 its sandy character accounted for by proximity to them, although there is no other 

 obvious factor to explain it ; Nos. 22 and 23, on the other hand, pebbles and sand from 

 210 and 214 fathoms respectively, obviously, both from their physical character and 

 mineralogical composition, largely take their origin locally from the rocks of these 

 islands. The several samples of Nos. 24 and 25 are shallow-water sands and muds 

 from the S. Orkneys ; No. 26a (from 59° 43' S., 48° 10' W., 2110 fathoms), on the north 

 side of the S. Orkneys, is a sandy mud bordering on Diatom ooze. 



For comparison with a Weddell Sea glacial clay I examined a sample of clay from 

 the Portobello brickfield, on the east side of the city of Edinburgh. This is, in ordinary 

 parlance, undoubtedly a clay and is a formation which has been laid down in the Great 



