720 



REPORT— 1884. 



Hudson they rise to 1,0()0 feet, at Albany 200, in tli(> C'hanipliiin Valloy, .irjO at 

 .Monln-al 500, in Labrador 800, at Ihiy'ia Strait 1,000, and at Polaris Ikv, ns'rf. 

 ported by Dr. IJi.ssell, 1,000 leetabovo the ocean level, 'rin'seclays contaiii Arotic 

 .shells from New York to (Jrecidund, and hence are yjiown to have been dep(i>it,.(l 

 duriiijr the ice period. 



Tim elevation of the northern position of the continent diirinp the Tertiiirv— 

 when land connection existed between America and Asia and between Americiimul 

 ]']urope, wliile a mild climate prevailed at the ntnth — and the depression ol' tin- 

 northern half of the ( 'ontiiient diirinpr the ice period nniko it impossible to arccpt 

 the lA'ellian hypothesis of topojrraphical chani,'es as causes of these diiU'renci's df 

 climate, and compel us to look to some extraneous iiilliience for the cause of the cnld 

 of the ice period. 



2. Marginal Karnes. Bij Professor IT. CAUVir,!, Lewis, M.A. 



During his exploration of the extreme southern ed<re of the ice-sln'ct in 

 Pennsylvunia tlie author had an opportunity of studying certain short ridges of 

 stratilied drift wliich appeared to represent in many cases a liarhward drainiKjo of 

 the melting edge of the glacier, and for which he proposed tlie uauK! mnnjiiud 

 kamcs. 



After describing the general characters of kames, eskers, and osars, as studied 

 in ditlerent parts of the world, the author reviewed tlie researches of Aincricnii 

 geologists upon this suliject, and discussed the various theories as to tho (iri<:in of 

 ihese curious deposits. He then described in detail a number of marginal kanus 

 in Pennsylvania, indicating their relationship to the great terminal moraine (from 

 which they are clearly to be distinguished), and to the lines of the present draina;:e. 

 He showed tiiat these kames are made of stratilied saiid and gravel, linest within 

 and often coarse without, that they have a rude anticlinal structure, that 

 boulders and till often lie on top of them, that they contain no shells or other 

 indications of having been shore-lines of any kind, and that while bcarint' no 

 relation to tlie movement of the glacier, their courses coincide with the general 

 drainage of the region in which they lie. 



It was argued that marginal kames are due to sub-glacial streams draining the 

 edge of the ice-sheet. >Vhen the terminal moraine rested against an upward 

 slope this sul)-glacial drainage was backward or into the ice. A study df the 

 terminal moraine had led the author to the pame conclusion, and a number of 

 examples were given to show in certain places the absence of any draiiiagi! 

 outwards from the glacier. 



Finally, the sub-glacial drainage of the modern glaciers of Greenland and 

 of Alaska was alluded to, as also the aqueous nature of much of the till in the 

 lowlands, all of which strengthened the conclusion arrived at concerning marginal 

 kames, and concerning an extended sub-glacial drainage of the American ice- 

 sheet. 



(The paper was illustrated by a number of lantern views of kames and 

 moraines, most of them from photographs taken in the iield.) 



3. Twelfth Report on the Erratic BlocJcs of England, Wales, and Ireland. 



See Reports, p. 219. 



4. 0)1 Fluxion- Strndure in TilU By Hugh Miij.er, A.R.S.M., F.G.S. 



It has long been recognised as one of tbe characteristics of the till that its 

 long-slia])ed boulders are striated lengthwise. They have, as it has been concisely 

 expressed, been 'launched forward end-on.' From the minute and magnitiahle 

 Btriai upon the smaller (e.ff. almond-sized) boulders it also appears that these at 



' Published as part ii. of a Paper ' On Boulder Glaciation,' Royal Physical Society 

 of Edinburgh, 1881. 



