174 H. Faher & W. K. S-pencer— 



of soft chalk occur. In this there are tnany layers of flint. Down 

 to 400 feet the flints are mostly black, from 400 feet to 900 feet 

 they are a white opal. The flint layers gradually disappear. The 

 soft chalk is succeeded by chalk with alternating soft and hard layers 

 (1,000-1,600 feet). From 1,600 to 1,700 feet there is a hard 

 limestone graduating to marl. From 1,700 to 2,742 feet the rock is 

 a marlstone with layers of light and dark marl, which increase in 

 frequency, darkness, and proportionate content of sand as the boring 

 deepens. 



The mineral analysis of the material suggests from the proportion 

 of sand to that of calcium carbonate that there was on the whole 

 a deepening of the water in which the rocks were laid down, but 

 the depression was not quite continuous. There appears to have been 

 a slight elevation during the period represented by the rocks met 

 with from about 1,850 to 2,250 feet, followed again by a lowering 

 of the floor of the sea. 



That this regular succession is accompanied by horizontal bedding 

 is shown by the larger pieces of chalk obtained from the depths 

 1,600-1,630 feet. At these de{)ths the chalk contained thin layers of 

 clay, and the chisel-marks were always at right angles to the layers. 

 Similar evidence of horizontal layers was obtained from lower depths. 



The palseontological evidence suggests that the following strata are 

 met with : — 



0-4 feet ....... Alluvium. 



4-34 feet . . . . . . . Diluvium. 



34-120 feet Saltholmskalk .... Danian. 



120-923 feet Skrivekridt with Flint . .\ , ^ . ni ii 



923-1,700 feet (about) Chalk without Flint .J^PP^" Mucronata Chalk. 



TMiddle and Lower ' Mucronata ' 

 1,700-2,742 feet Grey Marl with Sand . .- Chalk. 



1^' Quadratus ' Chalk. 



One of the first objections w^hich may occur to the reader is that 

 there is no certainty of origin of any of the fossils. The chisel in 

 being lowered might chip off a fossil at any depth from the sides of 

 the boring, and this would fall to the bottom and be listed as found at 

 a much lower horizon than that to which it really belonged. The 

 lining of the first 1,200 feet with steel tubes prevented, at any rate, 

 fossils from these depths (and the point is vital to the evidence) from 

 being mixed with the lower fauna. 



The great thickness of the 'upper mucronata' is of course very 

 surprising. No one would have imagined that the ' mucronata ' 

 chalk could have exceeded 500 feet in thickness, and it is necessary 

 therefore to examine very carefully the evidence upon which the 

 above table is based. 



The Skrivekridt with flints contained the following ' mucronata ' 

 fossils : Terehratulina gracilis, v. Schloth., sp. (270 feet) ; Cidaris 

 haltica (Schliit.) (780 feet). Fragments which appeared to be Lima 

 denticiilata, Nilss., sp., and Seaphites constrictus, Sow., sp., w^ere 

 found at depths of 330 and 511 feet respectively. 



The chalk without flints (923-1,700 feet) contained Scalpellum 

 cretcB, Stp. (1,274 feet), and Serpula conica, v. Hag. (1,280-1,360 feet). 



