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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. .Jail. 3,
Fig. 2. — Ideal Section of the Hirschberg.
Hirschberg.
a. Ideal fault and fracture.
b, c, d. Basalt.
e. Muschelkalk. e'. Bunter sandstone.
/. Tertiary beds and Brown-coal.
away under the basalt. And that is precisely the appearance which
the Hirschberg now presents to us. It is a remarkable fact, in con-
firmation of this theory, that a small Brown-coal deposit was pointed
out high up on the hills on the N. or N.E. side of the valley. I did
not visit it, and its important bearing on this question did not then
occur to me.
Another feature in both of these sections is also worthy of notice,
as differing from other localities where the Brown-coal occurs, viz.
the total absence of a marine fauna in the beds above the clay. In
most of the other localities the marine bed is regularly superposed.
From its"absence here, we must conclude that this, as well as some
of the other freshwater lagoons and swamps where the plants grew,
from the decay of which the Brown- coal was formed, were situated
at a so much higher level than the others, that they escaped being
submerged when the irruption of the oceanic waters took place.
I cannot quit this neighbourhood of Gross Almerode without
alluding to a remarkable hill of burnt clay, which occurs about half
a mile to the south of the village. Here on the summit of a ridge
is an isolated basaltic outburst between the Hirschberg and the
Meissner, but nearer the latter. At no great distance from it is a
vast mound or hillock of a burnt stone, which is neither more nor less
than the beds of tertiary clays metamorphosed into Jasper or Thon-
jaspis. This jasper varies greatly, not only in colour, but in struc-
ture ; in places having an earthy conchoidal structure, and in others,
one almost vitreous. There is a great diversity of opinion among
local geologists as to its origin, some referring it to a true geolo-
gical cause, others considering it as recent, and occasioned by the
burning of the bituminous shale or Leber-Erz.
Looking at the spot afterwards from a distance, its form was
distinctly seen as rising above the surrounding ground, and re-
sembling the crater of a volcano. I have little doubt myself that
the metamorphism has been produced by geological causes, probably
the escape of heated gases from below ; this is rendered the more