74 ' ' MAEIOX ' ' EXPEDITION TO DAVIS STRAIT AND BAFFIX BAY 



of transporting rock fragments and of forming part of the pack 

 ice. However, the proportion of the pack ice of such origin is 

 probably very small. Bergs on the other hand, are derived from 

 glaciers, most of which contain considerable debris. Thus even 

 though the pack ice occupies a much larger volume than the bergs, 

 the l3ergs probably contribute many more rock fragments to the 

 sediments. 



Smith " estimates that 70 per cent of the bergs that flow down the 

 west side of Davis Strait are derived from glaciers in the vicinity of 

 Disko Island near latitude 70° ; 20 per cent, from glaciers floAving 

 into Melville Bay, about latitude 75° ; and the remaining 10 per cent 

 mostly from northern Greenland and the northern archipelago. A 

 large number of bergs originate on the east side of Greenland, and 

 flow around Cape Farewell and up the west coast of Greenland, but 

 only a few cross Davis Strait and flow southward in the Labrador 

 current.^'- The Labrador current, although somewhat interrupted, 

 extends across the mouth of Hudson Strait; consequently bergs or 

 pack ice coming through Hudson Strait, in all probability do not 

 flow^ northward in Davis Strait. Therefore, limestone from the 

 Paleozoic formations in the vicinity of Hudson Strait presumably 

 is not deposited in the sediments of Davis Strait north of latitude 

 62°. 



Boggild ^^ found no limestone fragments in his detailed investiga- 

 tion of the bottom deposits ofl' the east coast of Greenland between 

 latitude 70° and 74°. This leads one to believe that the bergs arising 

 north of this region carry practically no limestone. Very little non- 

 crystalline limestone is reported from the east coast of Greenland 

 south of this area." Sample 26, lying off Cape Farewell in the path 

 of the bergs arising in east Greenland, contains no limestone. Conse- 

 Cj[uently one infers that almost none of the limestone in the sediments 

 of Davis Strait comes from east Greenland. 



Koch's ^^ authoritative treatise of the stratigraphy of Greenland 

 does not mention the occurrence of limestone in the vicinity of Disko 

 Bay. However, he does state that the Agpat formation of early 

 Algonkian age consists of quartzite, amphibolite, marble, dolomite, 

 and clay shales which are more or less metamorphosed. This forma- 

 tion outcrops at intervals from Nugsuak, slightly north of Disko Bay, 

 to Inglefield Gulf in North Greenland. From Koch's description 

 of the formation one gathers the impression that the amount of non- 

 crystalline aphanitic limestone this formation would supply the 

 glaciers flowing into Disko Bay, would not constitute a large propor- 

 tion of the rock fragments carried by these glaciers. 



Koch ^'^ in 1918 mentioned the prevalence of granitic rocks in the 

 vicinity of Melville Bay ; but later ^' he reports the probable exist- 

 ence of the Agpat formation in this region, because he mentions its 



" Op. cit. 



12 E. H. Smith, op. cit.. pp. 74-78. 



" O. B. Boggild. Samples of the Sea Floor Along the Coast of East Greenland, 74 1^ to 70 

 N. L., Med. om Gronl. v. 28, pp. 17-85, 1909. 



1* See footnote 8. 



^'Op. cit., pp. 14-15 and .".4-58. 



i« Lauge Koch, Den II Thule-Ekpedition til Melville-Bugten og Gronlands Nordkyst, 

 1916-1918, Geograflsk Tidskrift Bind 24. Heft vi, 1918. p. 221. 



"Lauge Koch, Stratigraphy of Greenland, 1929, p. 14. 



