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Proceedings of the Royal Society 
made sufficiently deep. In the Kalkberg and the Schildstein, 
a hillock to the west of the Kalkberg, they have penetrated the 
surface. In general, the gypsum forms but comparatively a thin 
skin over the unaltered anhydrite ; hut in the Kalkberg, the whole 
mass of the rock, which has been quarried to the very heart, is 
gypsum. The gypsum and anhydrite are a good deal like one 
another; resemble marble; compact, greyish-white in colour, and 
slightly translucent. The gypsum especially is full of fissures, one 
of which has been followed 130 feet deep, filled with dolomite; 
more commonly they are filled with a gypseous breccia, which in 
one of the fissures contained the hones of a recent hat (Vesjpertilio 
noctula). These fissures produce a false appearance of vertical 
bedding. The crystal Boracite is found in the gypsum and anhy- 
drite. It is only found elsewhere in the precisely similar gypsum 
rock of Alsherg, at Segeberg in Holstein. Non-crystalline, it 
appears in the Keuper gypsum of Liineville in France. 
No fossils exist. 
The gypsum forms an anticlinal axis, with the Kalkberg for its 
highest point, sinking away to the east under the town in the form 
of a narrow round-backed bank, which dips steeply to north and 
south. Associated with the anhydrite are brine springs almost at 
saturation point, coming to judge by their temperature from a 
depth of 400 or 500 feet. These have so exhausted the under sur- 
face that great subsidences have occurred. 
The points of geological interest connected with this locality are : — 
I. That it is far the most instructive, and indeed almost the only 
place in the great flat of Northern G-ermany, where the underlying 
strata have been brought to the surface, these being generally 
buried deep under sand and clay. 
II. That there is here an exhibition of a very peculiar agency 
by which these strata were elevated, and of the time when this 
occurred. 
One of these inferior strata is anhydrite, a sulphate of lime 
deposited from water, hut deposited without water of crystallization 
entering into its formation. Later, through exposure to moisture, 
it has accepted water into chemical combination with the sulphuric 
acid and lime, and thus changing to gypsum, has expanded to a 
