Oscillations of Land in Scandinaoid. 209 



touch the groimd with their tops, or tossing up flagstones into the 

 air so as to make them come down bottom upwards," etc. (p. 404.) 



" If upheavals and depressions of the land have not been caused 

 by changes of pressure, it may be asked, what is it they have been 

 caused by ? " (p. 405.) 



"If beneath that part of the surface which was affected by the 

 heavy pressure of the ice, there happened to be a quantity of lava 

 in a fluid state, the result might be to cause an outburst of the lava 

 to take place at some more distant point. This would relieve the 

 tension and lead to a permanent depression of the ice-covered area. 

 For example, in North America the great fields of ice that lay on 

 certain portions of that continent by their downward pressure may 

 have occasioned some of those extensive eruptions which seem to 

 have taken place in the region of California after the commencement 

 of the Glacial period. The volcanic phenomena of Iceland in like 

 manner may have been affected by similar causes. That there has 

 been a considerable permanent depression of some of the most 

 heavily glaciated regions since the commencement of the Glacial 

 period, I think there is much reason to believe. The features of the 

 fjord districts of Norway and the West Highlands of Scotland, and 

 of British Columbia, for example, seem to show this ; for these 

 coasts have all the appearance of depressed mountain lands, which 

 have been cut and carved by streams and glaciers far beneath the 

 present level of the sea." (p. 405.) 



"It seems likely that there might be a tendency to bulge up in 

 the region which lay immediately beyond this area of depression ; 

 just as we sometimes see in the advance of a railway embankment, 

 which not only depresses the soil beneath it, but also causes the 

 ground to swell up further off." (p. 461.) 



So far Jamieson. His ideas have, before me, been shared by 

 Whittlesey, N. S. Shaler,' and Warren Upham,- the last-mentioned 

 having developed them further. Upham calls our special attention 

 to the indisputable glacial formations that date from the Carboniferous 

 or Permian periods, as that in South Africa at 30° S. lat.,-' in India 

 at only 20° N.,'* as well as in Australia,^ and he correlates these 

 phenomena with the mountain-building that took place during that 

 time. Of the glaciated areas here mentioned I have myself visited 

 that in Australia, in the neighbourhood of Bacchus Marsh, just west 

 of Melbourne (37°-o8° S.), and can confirm the correctness of the 

 descriptions given. Here occurs a typical boulder-clay, of blue 



' " Fluviatile Swamps of New Eugland " : Amcr. Jouru. Sci., 1887, ser. in, 

 vol. xxxiii. See p]). 220, 221. 



- " Probable ('aiises of Glaciation," Appendix A to G. F. "Wright's " The Ice 

 Age in North America" ; New York, 1891. See also Amer. Geol., 1890, pp. 327 

 et sqq. ; and Amer. Journ. Sci., 1891, vol. xli, p. 33. 



^ A. Schenck, " Ueber Glacialcrscheimmgen in Siidafrika " : Verhandl. des VIII 

 dciitschen Geographentages in Berlin, 1889. 



* R. D. Oldham, "A Manual of the Geology of India," Calcutta, 1893. See 

 pp. 157 and 198. 



^ T. W. E. David, "Evidences of Glacial Action in Australia in Permo- 

 CarboniferouR Time" : Quart. Journ. Geol. Soc, 1896. Hi, p. 289. 



DECAKE IV. VOL. VIII. — NO. V. 14 



