FORCHHAMMER ON THE BOULDER FORMATION. 267 



15° to 80° This whole western part contains only small boulders, 

 and consists almost entirely of fine-grained sandstone, made up of 

 the quartz rock which so greatly abounds in the transition rocks. 

 Firestone also occurs. 



The case is quite different on the coast of the Cattegat. On 

 the island of Seeland the Brown coal formation appears in the 

 north-west at Cape Refsnaes, and on the north-western side of the 

 island of Fuhnen, on the north-eastern side of the duchy of 

 Schleswig, and on the eastern side of Jutland in the island of 

 Samsoe, and again on the south-western shore of the Cattegat. 

 The arenaceous members of the formation are here entirely absent, 

 and the rock consists of clay, which is sometimes of fine lami- 

 nated texture, and of variegated colours (blue, green, and red), 

 and sometimes of a black and brown colour, and glimmery appear- 

 ance, forming an excellent alum shale, and containing imbedded 

 pyrites. Below this are limestones, and here and there kidney- 

 shaped masses of radiating heavy spar, very much like Bologna 

 spar, and not seldom including masses of corals. Carbonate of 

 iron and thick brown spar likewise appear, and many crystals of 

 aragonite are distributed through the hard strata. The beds of 

 this series are variously elevated, but always by local elevations, 

 so that no general law of the disturbances can be discovered. 



I now proceed to give an example of the different contents of 

 the strata of this interesting group, as they appear in the neigh- 

 bourhood of Fredericia. 



The finely laminated clay is here curved and bent in the way 

 which one sometimes observes in gneiss. A little hill, near the 

 town, is capped by a bed of newer date (the boulder clay), which 

 appears to have suffered no change, and it is clear that the prin- 

 cipal disturbance must have occurred between the deposit of the 

 Brown coal and that of the boulder sand. It is worthy of remark 

 that the relative proportion of fragments of the cretaceous rocks 

 is always very small, varying from eighteen per cent, in northern 

 Fuhnen to twenty-five per cent, in other places ; the rest is made 

 up of about fifty per cent, of the old rocks ( Urgebirge), and thirty 

 per cent, of transition rocks ( Uebergangsgebirge). This is singular, 

 since the Brown coal formation rests immediately upon the rocks 

 of the cretaceous group, and one might therefore have expected 

 that many fragments of the latter would be included, but such is 

 not the case; and the newer deposit of the boulder clay is much 

 richer in this respect, containing fifty per cent, of cretaceous rocks. 

 It is also worthy of notice that only that part of the Brown coal 

 formation, which flanks the western edge of the Scandinavian 

 mountains, contains these boulders, and also that while not one 

 single specimen of Pecten is found in the whole of the western 

 Brown coal system of Jutland, fossils of this genus are very com- 

 mon in the Cattegat system, other species of shells however (e. g. 

 Nucula laevigata, JV. comta, and Pleurotoma oblong a) belonging to 

 both, and apparently proving the contemporaneity of the two 

 deposits. The cause of this peculiarity, viz. the absence of the 



