AND TRIAS OF CENTRAL EUROPE. 397 
which they have undergone, the granitic conglomerate of the Upper 
Rothliegende lying, as a rule, contiguous to the schists and porphyries, 
and more or less remote from the granite regions. The granite 
fragments are, some of them, of a porphyriti¢ granite, others rather 
fine-grained normal granite. They are identical with the granites 
exposed over many miles of the higher parts of northern Thuringia, 
across the Rennstieg, for example, all the way from Ruhla to Alten- 
stein and Liebenstein. In this district the coarse porphyritic granite 
predominates, but it assumes a more normal character towards 
Ruhla; and in one quarry about a mile from that village (famous 
in ancient legend), the one variety is seen passing into the other, 
and the two are commonly seen mingled together in the heaps of 
broken-up stone by the road-side. We may say, in fact, with Prof. 
Senft, that “the Rothliegende of the north-western Thiringerwald 
consists of the destruction-products of the Ruhla mountain-island ” 
(‘Gaea, Flora u. Fauna der Umgegend von Eisenach,’ by Dr. Ferd. 
Senft, 1882, p. 29). In the neighbourhood of Gera the inciuded 
fragments of the Rothliegende consist for the most part of quartz, 
clay-slate (with fucoidal markings), and culm-schists, furnished, along 
with the oxidized red marly matrix, by the older Paleozoic rocks 
of that district. Again in the Plauenscher Grund near Dresden, 
the syenite massif which extends over many miles of the kingdom 
of Saxony, has furnished the included fragments of the Rothlie- 
gende conglomerates for the most part. The uppermost strata 
of the Lower Rothliegende are generally bleached for several feet 
downwards, otherwise the character of the strata is the same as 
that of those below. In the Gera district, and especially in the 
Pfordener Berg, these are overlain normally by the Zechstein strata 
from the Kupferschiefer upwards. The change of colour is possibly 
due to the bleaching action of vegetable acids contained in the 
waters from the adjacent land, when the process of mechanical 
deposition of the materials became less rapid*. 
The Lower Rothliegende strata are, asarule, well-stratified aqueous 
deposits of a littoral character; but the same is scarcely true of the 
Upper Rothliegende as it is developed in North Thuringia. I have 
not seen the idea suggested anywhere; but the vast proportions of 
these deposits (e.g. about the Wartburg and Hohe Sonne), the 
angular nature of their included fragments (for the most part), and 
the feeble development of their stratification, as shown on their 
weathered surfaces, suggest, to my mind, a comparison with the 
mud-streams (Schlammstrome) which one meets with in certain 
Alpine valleys; that is to say, instead of being true sedimentary 
aqueous deposits, they are, as I take it, but indurated accumulations 
of streams of mud and stones from the once higher mountains of 
Thuringia, and thus constitute a true Dyassic “ diluvium”. 
This direct relation of the Rothliegende to the character of the 
adjacent land, which is so marked throughout that formation, and 
is generally wanting in the formations of the Trias, serves to establish 
* See communication by the author to Section C of the Brit. Assoc. Report, 
1883, pp. 504, 505. 
Q.J.G.8. No. 159. 2E 
