EVIDENCE EROM EUROPE 317 



kind must be registered therein, if Jamieson's version of the isostatic 

 theory is correct. Can special studies disentangle the effects of climatic 

 changes and isostatic changes in the Ohio basin? 



Similar, likewise unanswered questions arise in connection with recent 

 diversion of rivers in the marginal belt farther west. The Platte Eiver 

 is' an example. ^^ Have some rivers been reversed in their directions of 

 flow because of crustal warpings due to glaciation and deglaciation ? 

 AVas the Columbia Eiver temporarily diverted into the course of the 

 Grand Coulee, State of Washington, because of a marginal bulge across 

 the Columbia Valley below the northern end of the spectacular coulee? 

 The prevailing explanation by the damming action of the Okanagan 

 glacier ought not to have the field all to itself. Is the Eecent tilting of 

 this region, shown by systematic displacement of stream courses running 

 east and west, possibly connected with marginal warps of the earth^s 

 crust around the Cordilleran ice-cap, as expected on Jamieson's hy- 

 pothesis ? ^^ 



Evidence from Europe 



Since the preceding pages were written, it was found that Munthe, in 

 explanation of recent changes of level in the belt marginal of the Scandi- 

 navian ice-cap, has also adopted Jamieson's hypothesis. His own obser- 

 vations, compiled with those of Brogger, De Geer, and others, led Munthe 

 to assume peripheral sinking in the south Baltic region to the extent of 

 at least 125 meters since the glaciated area on the north began to rise. 

 He estimates the correlative subsidence near the outer edge of the conti- 

 nental shelf oif N'orway to be about 300 meters. He writes : 



"From what has been said above, it is evident that the opinion first ex- 

 pressed by T. F. Jamieson (1891) and later (1892) confirmed by myself may 

 to a certain extent be correct, namely, that a movement of land within the 

 central regions of the glaciated northern Europe also caused a gradual move- 

 ment in thje opposite direction within the peripheric parts, and vice versa.'' " 



In this connection reference may be made to Brogger's map of negative 

 (subsidence) isobases crossing Denmark, and to the recent sinking of the 

 fresh-water "Sanddiluvium" (Eemian series) in Holland to levels below 

 sea, deepening from 83 meters at Deventer to 200 meters at Amsterdam. ^^ 



20 U. S. Geol. Survey Bull. 612, 1915, p. 18 and references. 



21 J. T. Pardee : Bull. 677, U. S. Geol. Survey, 1918, p. 50. 



22 H. Munthe : Geol. FOren. Stockholm Forhandl., vol. 32, 1910, pp. 1197-1293, with 

 full, bibliography. Reprinted as Guidebook No. 25, Cong. geol. internat, Stockholm, 

 1910. 



23 W. C. Brogger : Norges geol. Unders., no. 31, 1901, pp. 681, 683 ; no. 41, 1905, map. 

 F. E. Geinitz : Die Eiszeit, Braunschweig, 1906, p. 98. 



Of course, sedimentary loading must also be considered as a possible cause of recent 

 subsidence in Holland. 



