March 21, 1889] 



NATURE 



49: 



up on the slopes of the Alps and far in the interior of 

 high continents. 



The marine deposits which are encountered all over the 

 globe high above the present sea-level are stratigraphically 

 of two very different kinds : viz. marine layers which 

 have been greatly disturbed from their original horizontal 

 position, upheaved and thrust up by the side rocks ; 

 and marine layers which, lying perfectly horizontally, form 

 the upper strata of the high plateaus, or of the table- 

 mountains. 



That the former, after having been deposited as mud 

 below the level of the sea, and afterwards hardened into 

 more or less solid rock, have been dislocated from their 

 original position by mechanical forces, and raised high 

 above the level at which they were formed, pressed 

 together, and thrown above each other, — about this all 

 geologists agree. Formerly the opinion prevailed that 

 the volcanic forces in the interior of the earth had 

 accomplished all this, but we may assume that most 

 geologists are now inclined to seek the cause of the 

 changes indicated in side pressure, dependent upon 

 various causes — a theory advocated by me twenty years 

 ago, but then little heeded. 



However, this explanation is no longer applicable to 

 marine layers which have not been disturbed in the least 

 degree from their original horizontal position, although 

 they at present form high plateaus several thousand feet 

 in depth and several thousand square kilometres in area. 

 .Such formations are, as is generally known, found in all 

 parts of the globe, and from all geological ages. On the 

 west coast of Norway, where no such rising of the land 

 in historical time as in Sweden has been observed, 

 one finds in many places, particularly in the north, 

 terraces or ledges which run perfectly horizontally, 

 irrespective of the geological structure of the coast, for 

 miles along the shore. Since attention was first drawn 

 to these terraces by Urban Hjiirne in Sweden, and by 

 Keilhau and Bravais in Norway, they have been the 

 subject of careful study, and of a literature as voluminous 

 as that relating to the land-rising question. No geologist 

 will now venture to deny that we have here before us 

 old shore-lines, indicating that the sea even during the 

 very last geological epoch, but still long before, very long 

 before, historical times, stood far above its present level ; 

 whilst the horizontal position observed everywhere, apart 

 from purely local exceptions, appears to contradict the view 

 that this is due to local upheavals. Similar formations 

 are also found in other parts of the world, as for instance 

 at the Cape and the southern part of South America, 

 proving that even there great changes in the level of the 

 sea have taken place since the beginning or middle of the 

 last geological epoch. 



Of layers from the Tertiary period we have, in conse- 

 quence of the erosion during the Glacial age, only traces 

 in Scandinavia ; but further north, in Spitzbergen, we find 

 Tertiary strata thousands of feet in thickness. Near the 

 west coast they are much disturbed, but further inland 

 they form almost horizontal strata of sand and clay, 

 here and there containing small coal-seams and schists, 

 rich in splendid fossil remains, bearing witness not only 

 to a magnificent vegetation having once existed in these 

 parts, now ice-covered, but to the fact that the sea at 

 Spitzbergen when they began to form hardly stood higher 

 than at present. When therefore Prof. Nathorst, during 

 one of his expeditions to Spitzbergen, on the highest 

 plateaus of one of these high but horizontal Tertiary beds, 

 found a mighty layer of marine fossils, we obtained proof 

 that during the Tertiary period, geologically speaking so 

 near us, the level of the sea had varied to the extent of 

 several thousand feet. Even here the perfect horizontal 

 position of the strata from Advent Bay by the Ice Fjord 

 across the Storfjord to Franz Joseph's Land, excludes the 

 possibility of these Tertiary marine beds being raised to 

 their present level by volcanic forces. And if we proceed 



from the Tertiary beds of the Arctic regions to those on 

 which Paris rests, or to those of the United States or of 

 Patagonia, we encounter everywhere proof that the level 

 of the sea has changed many times during the Tertiary 

 period. Analogous observations may be made about the 

 strata from the Trias, the Jura, and the Chalk periods 

 in different parts of the globe. Again, the geologist finds 

 that the level of the sea for some reason or another 

 during those epochs has changed by many thousands of 

 feet, in most places without its being possible to connect 

 this change with the oft-adduced reaction on the earth's 

 crust of the supposed red-hot interior ; and the same 

 applies also to layers from the Palaeozoic period, from the 

 period during which the rocks of West Gothia, referred 

 to by Swedenborg, were formed. 



Independent of all observations on the land-rising in 

 Sweden, and independent of all theories, the fact remains 

 that since the earth became an abode for animals and 

 plants, the level of the sea has changed many times. 



But we must confess that up to the present no accept- 

 able theory explaining the cause of these changes has 

 been proposed. Some have re-adopted Swedenborg's 

 ancient idea that a change in the rotation of the earth 

 caused a change in the form of the hydrosphere ; others 

 have discussed the great influence exercised by heavy 

 mountains on the water-level of the adjacent seas, calcu- 

 lating that under favourable conditions this may amount 

 to a great deal, i.e. that the sea-level on coasts that are 

 engirdled by great mountain ridges is several hundred 

 metres above the main level of the ocean in the same 

 latitude ; others, again, have sought the explanation in 

 the hypothetical, and to those who are familiar with the 

 Arctic regions wholly arbitrary, assumption, that huge 

 masses of ice are periodically heaped up at one or another 

 of the Poles, and by their attraction cause notable changes 

 in the sea-level ; and, finally, some maintain that the rising 

 of the level depends on dust and debris being either blown 

 or washed into the sea, and that the sinking depends on 

 water being absorbed by strata in the interior. But to the 

 student reckoning with figures, and who bases his re- 

 searches on actual observations and not on assumptions, 

 none of these causes explains fully and satisfactorily 

 the great and probably simultaneous changes of the sea- 

 level. To my mind the simplest explanation, and nearest 

 at hand, has never been duly considered. 



No doubt this neglect in some degree springs from 

 th?: still prevailing belief in the quantitative unchange- 

 ableness of the heavenly bodies, which with the 

 Aristotelian philosophy has penetrated the intellect of 

 natural philosophers. Kepler, on account of the sun 

 being obscured during three consecutive days in April 

 1 547, most probably by cosmic dust, opposed this prin- 

 ciple, declaring expressly, Ceeli materiain esse alterabilem; 

 but the belief in the old dogma was so little shaken 

 thereby that the scientific ban went forth from more 

 than one quarter against Chladni when he attempted 

 to demonstrate that cosmic matter does really fall upon 

 the earth. Now Chladni' s doctrine is everywhere accepted, 

 but even at the present day few geologists will assign to 

 the cosmic matter that falls on the earth an important 

 influence in the formation of new strata. Only a few 

 quantitative studies of the phenomenon itself, and an 

 unprejudiced estimation of the length of the geological 

 epochs, are needed to convince anyone how unjustifiable 

 this is. To my mind it seems fully proved that solid 

 matter, as well as gaseous, and fluid at a temperature 

 above o", is daily in great quantities brought to the earth, 

 and that through this fall, and by the masses of debris 

 carried by rivers and wind into the sea, the latter must 

 during geological ages have become filled, and its level 

 raised in a manner which would be totally opposed to 

 actual facts, if there were not other causes to counter- 

 act it. 



Such a cause might be found in the circumstance that. 



