74 Professor G. Forchhammer on the Downs of Denmark. 



vered by sand-downs. Similar beds of peat extend on the 

 west coast of Jutland to the south ; to the south of the Liim- 

 fjord they are under the level of the sea, and at the island 

 Sylt th€y are 6 or 8 feet under the level of the sea, and con- 

 tain large trunks of birch. Farther south they lie deep under 

 the Marsch, therefore far under the level of the present sea ; 

 and it is known that on the coasts of Holland and of Corn- 

 wall they likewise occiu: under the level of the sea. They 

 indicate that great sinking which took place in the present 

 epoch of the earth from the west coast of England as far as 

 the Liixnfjord, which gave the shores of the north sea their 

 present aspect, and, without doubt, either prepared for, or pro- 

 duced, the separation of England from France. 



The remaining features of the Martorv bed of Skagen and 

 Raabjerg are the following. In general there is only one bed, 

 whose thickness in some places amounts to 4 feet. It gene- 

 rally reposes on horizontally stratified beach-sand with de- 

 tached rolled beach-stones ; sometimes on finer less distinctly 

 stratified sand without stones, which is evidently drift-sand 

 which had been blown into the lake ; in other places on a 

 very distinctly stratified layer of fine silica, perfectly similar 

 to that which throughout Denmark lies under the lake-moors, 

 exhibits an organic structure under the microscope, and ac- 

 cording to the observations of Mr Steenstrup, contains fossil 

 infusoria ; here and there the beach-sand under the peat-bed 

 is united into a solid sandstone by iron, a bog iron formation, 

 which stands in connection with the titanic iron of the drift- 

 sand ; for everywhere in the valleys of the downs where the 

 downs are covered by plants, we find that beds of iron are 

 deposited, which are extracted from the sand by the slow action 

 of the humic acid. Although, as has been already said, there 

 is generally only one bed of peat, yet in some places we find two, 

 and at one point we have three (fig. 4, Plate III.) ; they are sepa- 

 rated by fine sand, and the two upper beds are sandy. At this 

 place it is evident that the formation of peat has been interrup- 

 ted by the down-sand blown into the lake, afterwards continued, 

 and again interrupted. That the whole is merely local is 

 plain from the connection of the three beds, and from the 



