part 2] A NEW MODE OF TRANSPORTATION 13 Y ICE. 51 



5. A New Mode of Transportation by Ice : the Raised 

 Marine Muds of South Victoria Land (Antarctica). 

 By Frank Debeniiam, B.A., B.Sc, F.G.S. (Read June 4th, 

 1919.) 



[Plate IV.] 



The old and somewhat vexed subject of the methods of trans- 

 portation of material Iry land- and sea-ice is again brought up in 

 this paper, a subject on which there is so voluminous a literature 

 that any attempt to add to it must have the support of the 

 strongest reasons. It is, therefore, with some temerity that I 

 attempt the description of a set of facts which appears to contain 

 a key to some of the well-known problems of ice-action. 



Of all the phenomena of glacial deposits, perhaps the most 

 puzzling are the occurrences of shelly drifts of marine origin in a 

 great variety of circumstances, both as to height and as to com- 

 position. The great discussions of the past as to whether the} r 

 indicated submergence, or merely an upthrust-action of the ice, 

 can only be said to have been suspended and not concluded. 



The subject of this paper is a series of deposits on the Antarctic 

 shores which point to an explanation of the origin of many 

 of these shelly drifts and the peculiar circumstances in which 

 they occur. In South Victoria Land we had the good fortune to 

 see these shelly deposits at an early stage of their evolution, a 

 stage now only possible in polar lands with a severe climate. 



The occurrence of raised marine muds, resting upon ice, was 

 reported by the first Expedition that wintered in the Ross Sea, 

 the British National Antarctic Expedition of 1901-1904. They 

 were described by Mr. H. T. Ferrar, the geologist of that expedi- 

 tion, who mentions several deposits of the kind, but does not 

 hazard any explanation. In association with the muds he found 

 deposits of pure sodium sulphate (mirabilite) also resting on ice, 

 which seemed equally inexplicable. 



The British Antarctic Expedition of 1907-1909 made important 

 new discoveries of a similar character, and in its geological report 

 a very dear account of them is given together with alternative 

 theories for their mode of origin. 



When we of Captain Scott's Last Expedition in our turn made 

 new discoveries of sea-muds and salts on ice the subject assumed 

 a greater importance by virtue of this proof of its widespread 

 occurrence, and it devolved upon me to search for a satisfactory 

 explanation. It must be admitted that such was not found until 

 the end of our stay, too late to verify some of the assumptions 

 that had to be made. 



Since any hypothesis on the nature of these deposits will rest 

 largely upon the details of their occurrence in the held, a full 



Q. J. G. S. No. 298. f 



