Strata of the Islands of Seeland and Moen. 2i5 



of H. R. H. Prince Christian, at Copenhagen. (See fig. 1.) It is probably Venericardia senilis 

 of the crag(So\verby Min. Con. tab. 258. figs. 1. 2. 3.), a shell whicli varies p. 



greatly in form, but of which I have seen some specimens from Suffolk, 

 which are equally transverse. 



I was informed that, at some places in the interior of Holstein, beds of 

 marl, used in agriculture, abound in this formation, containing about 

 twenty per cent., and often more, of carbonate of lime. In several places 

 between Schulau and Blnnkenese the stratified sand and loam gives place Left valve of a Venericardia 

 suddenly to the boulder formation, consisting of stiff blue and greenish ^'■<"« Schulau, Holstein. 

 clay, often entirely destitute of stratification, and having interspersed irregularly through it, 

 pebbles and blocks of granite, gneiss, hornblende-schist, white chalk-rubble, rounded and angular 

 masses of chalk, entire and broken chalk flints, black rounded pebbles of flint, and a variety of 

 other rocks. 



Although I believe the largest boulders occur chiefly in the upper part of this deposit, yet I 

 saw in the perpendicular cliff, near Blankenese, some huge blocks of granite distinctly imbedded 

 at a considerable depth. Professor Schumacher, of Altona, informed me that he had selected two 

 erratic blocks of granite, lying on the surface of this country, to serve as well-marked points for 

 the extremities of the base which he measured for his trigonometrical survey. One of these 

 blocks was about six feet square, and the other about eight feet long, by five in breadth and depth. 

 But others have been observed in Denmark of much larger dimensions, measuring no less than 

 twenty feet in diameter in two directions. 



I infer from the sections on the Elbe, that the stratified sand and loam were 

 originally continuous throughout the space where the cliffs now extend, and 

 that the sudden and abrupt manner in which the unstratified drift, containing 

 boulders, now occasionally replaces the sands, is owing to subsequent changes. 

 Such a relative position may perhaps be due to the engulphment, during 

 earthquakes, of superincumbent mud and boulders ; for 1 could not, when on 

 the spot, reconcile the phaenomena with the idea of valleys excavated in the 

 more ancient sands, and subsequently filled up with the boulder formation. 

 Under any hypothesis, it is difficult to conceive how such enormous heaps of 

 gravel, sand, clay, and boulders, have been collected together without any 

 arrangement, such as would be produced by the sorting power of running- 

 water acting on materials which diff'er in size, shape, and specific gravity. 

 Had the deposit been only a few feet thick, and all the boulders of moderate 

 dimensions, it might have been argued, that a violent current of water, or 

 diluvial wave, had thrown together materials of all sizes in one promiscuous 

 mass, and left them as devoid of arrangement as a quantity of rubbish shot 

 from a cart. For my own part, I am unable to suggest any conjecture to ac- 

 count for the phaenomena, except that of islands of drift ice, loaded with earth, 

 gravel, and blocks, or having these substances frozen into them, and then 

 melting. In this case, all the materials transported from a distance, might 



