266 GEOLOGICAL MEMOIRS. 



The formation resting immediately on the cretaceous beds is one 

 which covers by far the greater part of Denmark. It is the im- 

 portant Brown coal series, of which there are three great deposits. 

 The one of these farthest from the mountains, and that which is 

 the most regularly stratified, extends from Nissumfjord to the 

 south of Liimfjord, on the ridge of the land, and on the west coast 

 as far as the Elbe ; it re-appears through the gypsum upheaved 

 near Liineburg, and unquestionably forms a large part of the 

 Luneburg common. The uppermost bed consists of ferruginous 

 sand and a loose sandstone ; and below this are thick beds of clay 

 and marl, occasionally including unusually hard marly limestone. 



Alum earth is. also very common, and in detached spots there is 

 found a snow-white sand with mingled white clay, abounding with 

 glimmering particles ; while in the middle of Jutland by Them, 

 beds of brown coal appear in sand. The great abundance of brown 

 coal in this formation is best shown, however, by the fact that the 

 "Western Sea throws up this substance along the whole line of coast 

 from Liimfjord as far as the Elbe. There can be no doubt also, 

 that the amber belongs to this formation, since the amber is thrown 

 up in the same places in which the brown coal appears, and to 

 such an extent, that about 3000 pounds weight are annually pro- 

 cured. The clay and limestone of this formation, and sometimes 

 also the sandstone, contain fossils which mark the age of the de- 

 posits to be identical with that of the sub-Apennine group. Among 

 the most important of these are, — 



Cassis testa, Pleurotoma cataphracta, 



Cassidaria echinophora, Dentalium striatum, 



Nucula comta, Trochus agglutinans, 



glaberrima, Triton anus, 



Fusus corneus, Isocardia cor, 



together with another Isocardia somewhat different, and a Rostella- 

 ria very much resembling R. pes pelicani. There are also found 

 crabs overgrown with species of Balanus,&ji& the bones and vertebra 

 of Cetaceans. The fossils are, however, on the whole not very com- 

 mon, and chiefly appear heaped together on the south-eastern side 

 of the island of Sylt. On this island the members of the formation 

 before described are seen upheaved by an elevation corresponding 

 to that of the island of Heligoland, and striking N. N.W. and 

 S. S. E., the beds dipping towards the E. at angles varying from 



bited themselves by a liberation of carbonic acid providing material for the coral 

 reefs. Afterwards, however, the forces increased and elevated the mountain 

 chain, the powerful waves thus produced destroying the coral reefs and depositing 

 the coarser fragments, as coralline chalk and the finer mud, at a greater distance 

 from the centre of disturbance as newer chalk. 



This he supposes to be the first result produced by the elevation of the Scan- 

 dinavian mountains in the way of filling up the bed of the sea from the sub- 

 sequent elevation of which Denmark was formed. Rolled Scandinavian rocks 

 are not found in the coralline chalk, where we rarely find any thing larger than 

 grains of sand and very small stones, (p. 614.) 



