1889]. THE DISPLACEMENT OF BEACH -LINES. 53 



ice-age (purple boulder-clay, arc 2"). A new upheaval seems to 

 have followed, with a new interglacial epoch. Then came a 

 third rise of the sea, which was very considerable, and which, 

 in Wales, at Moel Tryfaen, at Macclesfield and in Ireland, has 

 left marine shells at heights almost approaching to those in which 

 the old Norwegian „seter" or beach-lines in Osterdalen, Lsesje 

 etc. are found 1000—1300 feet above the sea. 



Like the previously mentioned inundations, this was also 

 followed by a glacial age, the last, Hessle boulder-clay (arc 3"). 

 And finally the land was upheaved and the ice melted. The 

 Post-glacial age, with its 4 teds of peat (the final part of 3" 

 and 4") arrived. A slight oscillation of the sea immediately 

 preceding the present time corresponds to the arc 4". In Skane 

 (Southern Sweden) the „Garavallen", an upheaved marine littoral 

 formation rests on peat; in Gotland, in the British Islands (Carse- 

 clay etc.), indeed, even in North America, the same oscillation of 

 the sea may be traced ; it was without doubt too great, to be cap- 

 able of explanation by local circumstances, compression of beds 

 of peat by shifting sand-dunes etc. 



We have seen, above, that the land (cfr. Howorth and Suess), 

 in many places in the higher latitudes, rose considerably in the 

 Post-glacial age, and that a corresponding lowering took place 

 in the warm coral-oceans. The last oscillations have therefore 

 included large parts of the Globe. From this we must conclude 

 that the same was the case with the oscillations also in the 

 former ages, and that they are caused by general cosmic con- 

 ditions. The slight oscillation (arc 4") forms an interruption in 

 the great Post-glacial upheaval in higher latitudes. A similar 

 interruption in the lowering must, if our theory is correct, be 

 found in the tropics ; and, in fact, there are found, both in Ame- 

 rica's and the Old World's equatorial regions, numerous proofs 

 of such a slight post-glacial oscillation in coral-reefs which are 

 upheaved a few metres and now lie quite dry (vide Suess Ant- 

 litz der Erde, II, p. 630 ft). These coral reefs probably date from 

 the same period in which the peat beds of the north were in- 

 undated. The peat-beds, with the superimposed marine beds have 



