FORCHHAMMER ON THE BOULDER FORMATION. 263 



navian boulders, it would be difficult to find a country which 

 affords so much assistance in solving the most difficult problems on 

 the subject as Denmark, where an extensive line of coast offers 

 numerous opportunities of obtaining an insight into all the circum- 

 stances relating to the rocks of that country. I have occupied 

 myself for many years in endeavouring to make out the geological 

 relations of Denmark with regard to this matter, and I may be 

 allowed to state at the outset, that the notion of this boulder form- 

 ation being a mere surface phenomenon is quite incorrect, since 

 it has reference to the whole tertiary period, even reaching so far 

 back as the time of the deposit of the newer cretaceous beds. It 

 will be necessary therefore to recapitulate briefly the relations of 

 the cretaceous rocks in Scandinavia. 



The carbonaceous deposits of Schonen and Bornholm, which 

 contain a great number of iron-stone bands, and which from their 

 fossils might be referred either to the Lias or the Jurassic period, 

 are succeeded at Bornholm by another carbonaceous deposit with- 

 out iron-stone, and containing no other fossil than Fucus intri- 

 catus. This newer deposit seems identical with the Carpathian 

 sandstone and other fucoid sandstones of the Alpine chain, and 

 does not belong to the lower part of the cretaceous series ; but 

 upon this bed, which has not yet been found in Schonen or in Den- 

 mark proper, the upper greensand is superimposed unconformably, 

 the lower series being frequently inclined at high angles (50° or 

 70°) towards the old rocks in the vicinity, while the overlying 

 rocks dip only at an angle of about 10°, and that in the opposite 

 direction. 



The upper greensand appears on the south-west coast of Born- 

 holm and in Schonen, where it has been described by Nilson. It 

 consists partly of sandy and partly of marly beds, whose fossils are 

 the same in both of these districts. The greensand is succeeded 

 at Bornholm in regular development and conformable stratification 

 by the marly limestone of Arnager, resembling very closely the 

 Saxon Planer. In Schonen there only appear in detached por- 

 tions masses of limestone consisting of fragments of shells and 

 corals, and these are probably referable to the upper greensand. 



During the past winter I have been so fortunate as to discover 

 in the neighbourhood of Kjoge in Seeland a greensand, which 

 most probably belongs to this part of the cretaceous period. The 

 presence of the easily worn schists of this formation explains the 

 deep intersection of the Kjoger Bay, between the hard Saltholm 

 limestone of Amack and the fire-stone bands of Stevens Klint. The 

 abundant springs of Brondkilde, Rothschild, &c, belong to the 

 same formation, and all of them strike S.E. and N.W. 



In the south-western part of Schonen, on the island of Saltholm, 

 in Sunde, below Copenhagen, and in Jutland, in the neighbour- 

 hood of Greenaae, a band of limestone appears which may be 

 traced by detached fragments and reefs in the Cattegat, between 

 the points before mentioned. This limestone, which is hard and 

 compact, seems, according to its geographical position, to underlie 



s 4 



