12 



JAMES CHUMLEY:— DEPOSIT-SAMPLES 



An interesting point in connection with the "Michael 

 Sars" deposits is the number of instances where the 

 sounding-tube had plunged deeply into the sediment, 

 bringing up sections varying from two to fourteen inches 

 in length, though in some cases marks observed on the 

 outside of the sounding-tube indicated that it had pene- 

 trated still further into the deposit. Though in most cases 

 the material was apparently uniform throughout, some of 

 these long sections gave distinct evidences of stratification. 

 Thus at Station 100 Globigerina Ooze was found over- 

 lying Blue Mud. The lower portion of the sample from 

 Station 10 was mottled light and dark brown, the dark 

 portions approaching Red Clay in composition, while the 

 rest of the sample was a characteristic Globigerina Ooze. 

 The upper portion of the Globigerina Ooze from Station 

 49 C showed similarly patches of lighter and darker brown, 

 the dark brown material proving on analysis to be a 

 Red Clay with less than 30 per cent, of calcium carbo- 

 nate. The middle portion of the section from Station 34 

 (Pteropod Ooze) showed dark coloured patches containing 

 a large proportion of volcanic glass splinters, to which 

 the dark colour was due. 



Coccoliths were observed in every sample except 

 one from the Mediterranean. Rhabdoliths were noticed 

 in nearly half of the samples, mostly in the eastern portion 

 of the North Atlantic, only two stations (51 and 63) lying 

 to the west of the Azores. Similarly coccospheres were 

 recognised in six samples from the eastern North Atlantic, 

 and in only one sample (Station 63) to the west of the 

 Azores. 



In the determination of the mineral species enume- 

 rated under the heading of "Minerals" we have had the 

 assistance of Dr. G. W. Lee, of the Geological Survey 

 of Scotland, who remarks that on the whole we are 

 dealing principally with minerals of continental origin with 

 an admixture of volcanic particles, and that quartz occurs 

 at the greatest depths. 



The rock-fragments brought up at Station 95, Dr. 

 Peach concludes, are not the debris of rocks in situ, but 

 may be matched by rocks occurring in the west of Scot- 

 land and northern and western Ireland, and have been 



transported by floating ice during the period of maximum 

 glaciation. The specimen of nepheline syenite may even 

 have been brought by part of the "polar pack" since 

 glacial times. More than half of the specimens are ice- 

 moulded or well glaciated, and some of the glaciated 

 stones have nests of boulder clay attached to them which 

 must have been transported with the stones. Most of 

 the stones had only about one-third (many of them even 

 less) of their bulk embedded in the ooze, some of the 

 more elongated specimens being embedded on end, and 

 the flat specimens on edge; so that they seem to have 

 been dropped upon, and to have sunk into, a flocculent 

 ooze, until they reached a layer of sufficient tenacity to 

 prevent further sinking, being at first totally buried and 

 subsequently partially exposed as the result of current 

 action. The rock specimens from Station 10, most of 

 them glaciated, are identical with those from Station 95, 

 and evidently derived from the same sources and distri- 

 buted by the same agencies. The rock fragments from 

 Station 48 appear to indicate the influence of the northern 

 drift ice, although situated south of lat. .30° N. The striated 

 stones from Station 70 have probably been derived from 

 the Arctic regions, since this station is situated in the 

 direct route of the icebergs and pack-ice brought down 

 by the cold current. The sandstone from Station 101 

 is like the Brenista flags of Shetland, and may have been 

 transported by floating ice beyond the limit of the great 

 ice-sheet. 



Referring to the association of these glaciated rock 

 fragments with cinders from steamers Sir John Murray, 

 in a lecture delivered before the Royal Scottish Geo- 

 graphical Society in Edinburgh on 11th November, 1910, 

 made the following interesting remark: — "If steamers 

 using coal should some day be superseded by vessels 

 using some other kind of fuel, then the deposits in the 

 North Atlantic would have a layer which might be called 

 the coal-fuel layer. On the other hand, if the coal-cinders 

 and these glaciated rock fragments are now lying together 

 on the floor of the ocean, geologists may in the remote 

 future find proofs in these layers that man and steamers 

 existed in the glacial period." 



