File:The Quarterly journal of the Geological Society of London (12711710663).jpg

424
PROCEEDINGS OF THE GEOLOGICAL SOCIETY. .Apr. 4,
the various angles of inclination which they present to the miner who
explores them. This tract oifers clear evidence, that the porphyritic
eruptions were not only violent, but successive and numerous during
the period of the Rothe-todte-liegende, and that they overflowed strata
of that formation in the form of submarine coulees. Here also, as
indeed in many other parts of Central Germany, we learn how these
dejections of contemporaneous porphyry and amygdaloid have been
occasionally so mixed up with pebbles and sand of the then existing
sea, as to render it difficult in such cases to decide whether the stra-
tum should be considered as one of igneous or of aqueous origin. In
all such extreme examples, however, the geologist who is seeking
after a truthful explanation of the works of nature will admit that
such strata are not to be dogmatically defined by one mineral term
only, but that, like the volcanic grit or ash of earlier periods, they are
to be viewed as true indications of the internal heat of the crust, which,
in bursting forth repeatedly, gave rise to those peculiar deposits which
resulted from a combination of subaqueous and volcanic causes.
Weiss- or Grau-liegende — Kupfer-schiefer — Zechstein, ^c.
Weiss-liegende. — The sandstones, breccias, and conglomerates of
which we have just spoken are succeeded in this region, as in many
other parts of Germany, by a band differing from all beneath it in
its light grey or whitish colour, as derived from a quantity of pebbles
of white quartz in a grey paste. This is truly a conglomerate made
up of rounded small stones, which present all the appearance of having
been formed by waves upon a shore. Since it forms the natural base
of the Copper-slate, the miners necessarily applied to it the name of

• ' liegende," as underlying the productive mineral stratum. This bed
  

or band (for it varies in thickness from 3 or 4 feet to 30 or 40) may
be properly considered the base of the Zechstein or Magnesian lime-
stone division of the Permian rocks, since in it, after ascending through
the siliceous strata of the Rothe-todte-liegende, we first find calcareous
matter beginning to show itself, and with it a few rare fossils.
Fig. 4. — Diagram showing the Succession of the Fermian Rocks on the
Flanks of the Thuringerwald. Horizontal distance about 4 miles.
d. Lower Bunter. eS. Sandschiefer. ".
c4. Upper Zechstein (Dolomite).
/ 3. Lower Zechstein. ! Permian
c2. Kupfer-schiefer. j Rocks,
cl. Weiss-liegende.
b. Rothe-todte-liegende. J
a. Coal-strata (Upper Coal).
p. Porphyry.
The accompanying diagram (fig. 4) shows the position of this