784 
MR J. M. WORDIE ON 
in depth), but also in depths of as much as 2000 fathoms ; it differs from Deep-Sea 
Terrigenous Deposits in there being no arrangement of the constituents according to 
size, the transporting agency being a solid, namely, ice ; and it differs from Blue 
Mud both in colour and in the fact that there is practically no carbonate of lime 
present in the deposit and very few organic constituents.* 
As regards the Weddell Sea deposits, Pirie seems to imply that the distribution 
of clay lies farther out from the continent than the mud. On the Endurance , 
however, it was noticed that deposits on the shelf were fully as worthy of being 
called clays as those from deep water, at least as far as macroscopic evidence went. 
The consistency, indeed, of the bottom deposit might vary very rapidly in a very 
small area. One day the lead would plunge in to the depth of a foot into soft mud, 
and the next, but a few miles away, sink only about half an inch into tough clay. 
Sand or grit was frequently present, but never in large quantity except off Coats 
Land, where some of the deposits were labelled as sand rather than mud ; and in 
70° S. lat., 40° W. long., where for the space of a week in the middle of April 1915 
the deposits were all very sandy. This unusual feature makes it quite possible that 
at the latter place the Endurance was nearer land than at any other time after 
leaving Coats Land ; absolutely no sign, however, of what might be land was seen 
from the crow’s-nest. 
The proportion of rock fragments, mainly small pebbles, was highest along the 
Coats Land coast. Pebbles and boulders, however, were likely to occur at any time, 
and particularly when a bottom sample was procured by means of the dredge. These 
rocks were always very carefully examined (as hand specimens, and not under the 
microscope) in view of the complete lack of knowledge of Coats Land geology. 
Considering the ice-bound nature of that land, it seems very unlikely that exposures 
of rock will ever be found there in any quantity, so that any data, however scanty, 
obtainable from bottom samples such as these must be of value. 
Geology of the Rock-Fragments. 
The rock specimens obtained directly off Coats Land are best treated separately 
from those got farther west in the Weddell Sea, as their source is not so much a 
matter of doubt. On January 12, 1915, in 74° 07 ' S., 23° 02' W., a dredging was 
made in 103 fathoms and brought up a sandy deposit full of sponge fragments and 
small pieces of rock. Among the latter, granite with white felspar was the commonest 
igneous rock ; basalt and dolerite were not quite so abundant ; a grey grit was much 
the commonest sedimentary rock, and a purple sandstone was found, but not in any 
quantity. At a later date, in 76° 34' S., 31° 27' W., the dredge yielded, in addition 
to granite with white felspar, another variety with hornblende and red felspar ; 
* Murray and Renard’s classification as given in The Depths of the Ocean , p. 161, requires a slight alteration' 
accordingly. “ Glacial Mud (and Clay) ” should be inserted after “ Coral Mud,” grouped on the one side with “ Deep- 
Sea'Deposits” and on the other with “ Terrigenous Deposits,” 
