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X. — Scottish National Antarctic Expedition, 1902-04 : Deep-Sea Deposits. By 

 J. H. Harvey Pirie, B.Sc, M.D., Geologist and Surgeon to the Expedition. 

 (With a Map.) 



(MS. received March 15, 1913. Eead May 26, 1913. Issued separately August 29, 1913.) 



The material brought home by the Scotia and available for examination consists in 

 all of fifty-five samples of deposits from the floor of the ocean. The majority of these 

 consist of true "deep-sea" deposits, i.e. material from depths of over 100 fathoms; 

 but, for convenience, the description of a few samples from shallow waters (mostly in 

 the neighbourhood of the S. Orkneys) is also included in this report. 



The number of deposits is considerably less than the number of soundings taken by 

 the Expedition, because, for various reasons, a sample of deposit was not obtained in 

 every case where a sounding was taken. 



In the majority of the shallow- water soundings taken in the neighbourhood of the 

 Expedition's winter quarters in the S. Orkneys, a simple sounding-lead was used and no 

 effort made to obtain a specimen of the mud from the bottom. In the case of the 

 deep-sea soundings a lead was also used in a few of the earlier soundings taken between 

 the Falkland Islands and the S. Orkneys, and in these cases, although a small amount 

 of material was obtained from the tallow on the bottom of the lead, such samples 

 cannot be regarded as giving, a true representation of the nature of the sea-floor, and 

 the material available is too small for a full examination. Sometimes the sounding- 

 tube came up empty ; on one occasion at least this was due to the fact that a tube 

 (Buchanan) was used without any rubber valve at the top, so that the plug of mud, 

 which probably had been in the sounding-tube, could easily have been pushed out 

 during the rapid raising of the sounder from the bottom. On several occasions there 

 was evidence from the presence of dents on the tubes that it had gone down on " hard 

 ground" — whether a general rocky bottom or an isolated boulder of rock, it is, of course, 

 impossible to say with certainty in every case ; but from the fact that in one or two 

 instances a subsequent trawling from the same situation brought up an abundant 

 supply of soft material, the likelihood would be that in these instances at least the 

 tube had simply happened to light upon one of the boulders which, dropping from 

 melting icebergs, must be scattered fairly thickly over the floor of the Antarctic and 

 sub- Antarctic seas ; in no instance did the emptiness of the sounding-tube appear to 

 be due to the bottom material being of so clastic a nature that it had not sufficient 

 cohesion to remain in the tube during the process of hauling up. Another reason for 

 each sounding not furnishing a sample of deposit is to be found in the snapping of the 

 sounding-wire and loss of sounding-tube (and perhaps also water-bottles and thermo- 

 meters, to say nothing of many fathoms of wire). This, unfortunately, was a not 



TRANS. ROY. SOC. EDIN., VOL. XLIX. PART III. (NO. 10). 86 



