8(5 



A. BLYTT. 



tidal-forces vary directly with the eccentricity, and that the 

 strain accumulates, consequently, with greater speed during high 

 eccentricity; we must believe that all these things together 

 will release strain, and cause the great eccentricities to be ac- 

 companied, in weaker places of the crust, by such displacements 

 of the beach-lines as those to which the geological stages bear 

 testimony. 



We know that the mean value of the eccentricity changes 

 through long periods. In hundreds of thousands of years it some- 

 times is as low as 0.0203, whilst in other hundreds of thousands of 

 years it may attain a value of 0.0340. And this must probably 

 have effect. In those hundred thousands of years when the 

 mean value is greater, the strain will accumulate somewhat more 

 quickly, and the mean effect of the releasing forces (nearness of 

 the sun in perihelion, spring-tides, low barometric pressure) will 

 also be greater. In Middle Europe great upheavals took place in the 

 Miocene epoch. In that epoch, during volcanic eruptions, several, 

 previously marine, basins were lifted above the sea for long per- 



he movements are not synchronous everywhere, 

 or instance, Oligocene beds occur only in the south- 

 ocene only in the northern. And this probably shows, 

 ■ent parts of the country were upheaved at diffe- 

 L'he great upheaval in the higher latitudes is of 

 date. Marine Tertiary formations are rare in 

 cts. ihey are known to occur in Spitzbergen. 

 Greenland, and around the Behring Sea. But they 

 teent in those parts of the higher North where 



