DR BOUE' ON THE GEOGNOSY OF GERMANY. 99 
Upon the chalk, the Plastic Clay, or Argile plastique^ 
is widely distributed in Germany, especially in the north- 
ern parts. Indeed, the greatest portion of that immense 
track of alluvial country (improperly so called), from the 
Rhine to Konigsberg, belongs to it. It seems only that 
the coarse marine limestone and first fresh-water forma- 
tion are almost entirely wanting, and that this clay and 
these sands are covered by the upper marine sandy de» 
posit of Paris, to which would belong, perhaps, also the 
granite-blocks, &c. The same will be the case with the 
great arenaceous deposit of the Bavarian flat country, of 
the neighbourhood of Vienna, and of the bottom of the 
immense Hungarian basin : but in these two last localities, 
the coarse marine hmestone is of pretty frequent occur- 
rence. 
In the north of Germany, the plastic clay often contains 
petrifactions ; as in the Magdeberg, near Halle ; in Lusatia, 
&c. The brown coal, which occasionally contains earthy gyp- 
sum, as at Halle, and, in other places, amber, always fresh- 
water shells, also coleopterous and fresh- water insects, occurs 
in considerable abundance in the plastic clay in the north of 
Bohemia and Thuringia ; and from the Rhine to Konigs- 
berg, geologists have observed, especially in the basins of 
existing rivers, a series of these deposits ; for instance, near 
Koln, in the valley of the Weser, in Thuringia, below the 
town of Berlin, and farther to the north-east. In Slavonia, 
it contains great masses of sulphur ; and in Hungary, and at 
Vienna, small pieces of realgar. The very compact sandstone 
which this formation sometimes contains, and which often 
abounds in fragments of flint, js, for example, very well 
marked near Zeitz, Beuchlitz, Blansko, Carlsbad, and 
Toplitz, where it contains the quartz-crystals which had 
once formed a part of the floetz porphyries of the neigh- 
bourhood. 
c o 
