Geology of England and Wales, §c.” 229 
united by an an argillaceous cement. These rocks con- 
tain subordinate beds of coal and limestone; the former 
being thin and poor. ad and copper and iron ores, sat- 
in spar, kitumen, petroleum, naptha, and asphaltum, also 
occur in the shale and grit. The fossils are similar to those 
Carboniferous or Mountain Limestone. This rock occasion- 
ally alternates with shale, grit and amygdaloid, and some of 
its synonymes are metalliferous limestone, and entrochal, or 
encrinal limestone. 'We-cannot here enter into a particular 
description of this interesting rock, but remark, that its strata 
are often divided by thin partings of clay, and that it con- 
tains nodules of chert, and is extremely cavernous. - 
tween 60 and 70 caverns are mentioned, as existing in this 
rock, in England and Wales; and also several subterrane- 
an rivers. It is the grand depository of the English lead 
mines. Various copper, iron, and zinc ores, fluor spar, cale. 
spar,arragonite, selenite, carb. and sulph.of barytes, sulph. of 
strontian, also occur in it; besides various minerals in the 
accompanying toadstone. The organic remains are very 
distinct from those in the oolitic series and the lias, and 
belong, chiefly, to extinct genera. Vertebral animals are 
rare ; but Zoophytes, Encrinites, Coralites, and Testacea 
are numerous. The strata are often highly inclined and 
orted. 
slate, &c. “its colour is usually dirty iron-red or 
brown, but sometimes passing into gray.” From the new- 
er red sandstone it may be distinguished by its greater con- 
solidation, but it is not so easily discriminated from the 
i i It is, therefore, 
highly pr that many rocks have been denominated 
old <i ete that reals belong to formations widely 
removed from it. It is often asserted, that coal is contain- 
ed in, or lies beneath, old red sandstone. But the authors 
w 
1 iety thus designated, unless it the coe 
aed They ests y even the red dead lyer, (rothe 
