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not only altered the structure of all the neighbouring rocks, but 
literally broken the chain into fragments, several of which are 
thrown into a reversed position. 
The igneous rocks of the region are stated to be of four kinds: 
(1.) Trappean rocks in beds and protruding masses, nearly on the 
line of strike; (2.) Granite, sending veins into the older slates and 
trappean rocks; (3.) Quartziferous porphyry in masses and dykes, 
identical in structure, and apparently in relation with the Elvans of 
Cornwall; (4.) Trappean rocks (melaphyre, &c.), associated with the 
rothe todte liegende and coal-measures on the south-eastern skirts of 
the chain. 
Silurian fossils are found in several parts of the Hartz, but the authors 
saw no rocks which they could compare with the central slates of the 
Ardennes, or the oldest slates of the Rhine; but they give two sec- 
tions which ascend into a higher system. The first is from Huli- 
genstein to the neighbourhood of Clausthal, and appears to give the 
following ascending order : 
1.) Devonian limestone, well characterized by its fossils. 
(2 A series of psammites and shales, with one or two species of 
Possidonia. 
(3.) A series of coarse sandstones and grits, surmounted by 
shales and psammites highly charged with plants, and mineralo- 
gically resembling the Devon culm-beds. 
Plants are, however, found below the Devonian limestone, and 
even thin bands of culm; and the section is obscure: but if the in- 
terpretation given to it be correct, a part of the country near Claus- 
thal rises into the carboniferous series. 
Their next section commences with the limestone of Ebingerode 
(on the south side of the Brocken mountain). The limestone 
abounds with Devonian corals and other fossils, and some parts of 
it cannot be distinguished from the lower limestone of Westphalia. 
Other parts of it are pierced with trappean rocks and are overlaid by 
ferriferous deposits; in which respects, as well as in its fossils, it is 
strictly analogous to the Devonian limestones of Dillenburg and the 
Lahn. Again, the ferriferous bands are overlaid by black shale, 
containing Kiesel schiefer, and (if we are not misinformed) contain- 
ing Possidonia schist. ‘The analogy presented with the uppermost 
part of the Devonian series in Westphalia seems, therefore, perfect. 
From these facts the authors conclude, that the older rocks of the 
Hartz are chiefly Silurian and Devonian, with a few traces of the 
lower carboniferous. 
If the great contortions and strike of the Rhenish provinces were 
produced contemporaneously with those of the Hartz, then must 
the great derangements of the Hartz have taken place after the de- 
posit of the Belgian and Westphalian coal-fields. But the principal 
dislocations of the Hartz must have taken place before the deposit 
of the red conglomerates, sandstones, coal-beds and trappean masses, 
which rest on its eastern flank. Hence the authors conclude, that 
none of these red conglomerates are of the date of the old red sand- 
stone; and that the coal-beds belong to the highest part of the car- 
