102 
THE GEOLOGIST. 
are largest parallel to tlie strike, and are crossed at ri^ht angles by others, 
cutting it up into immense square blocks, in their turn broken by smaller 
fissures into smaller blocks; the surface stone is called the "clint"or 
" clint cap," which affords a good stud}" of the way molecular attraction, or 
adhesion, has acted when the material forming the stone was in a viscid 
state. There is another set of fissures on Asby Scar, containing copper 
ore. In other formations of the same rock, small cracks have, by the pro- 
colation of water, often become soldered up by the crystallization of car- 
bonate of lime. On forcing these open again, large specks of lead ore are 
sometimes found, a fact which, in part, may svipport the theory of lead be- 
ing a deposit of crystallization of water. The characteristic fossds are 
Producti, which are very numerous, but ill preserved, and often distorted 
Euomphalus, Goniatites, and the black palatal bones of ganoid fishes. 
Some of the limestones, and all the sandstones, in this series of rocks 
appear as though the material of which they are formed had settled one 
stratum above another, without any upheaval of the bottom of the sea, 
and are of one continued thickness throughout, to the outcrop ; while 
others suggest the idea that the bottom has been gradually pushed up by 
some upheaving power, or that the current bringing the sedimentary 
matter failed to reach the outcrop, the stratum breaking off considerably 
further back, and the next stratum further still. 
The next sandstone is very thin ; above it is a thin limestone of a hard 
texture, in which Crinoids first became numerous ; its last surface afforded 
a floor, on which have grown immense forests of Encrinites. Clay shale 
of a dark colour is next superimposed by a grey purplish sandstone, con- 
taining Stigmaria. In its uppermost beds on Harbyrn Kigg, immediately 
below the limestone, are beds of Pectens, and other shells. The succeed- 
ing limestone is very thin, and almost exclusively made up of broken coral ; 
on two or three points, where it shows itself on high land, there is a 
stratum of coral, — clear evidence of an ancient coral reef. Next in order 
is a thin sandstone, generally overlaid by the next limestone : upon it 
rests another stratum of sandstone, associated with which are definite traces 
of another of the old coast-lines, exhibiting the variety of material forming 
a beach. The sandstone contains immense quantities of Stigmaria; at one 
place where a large area is laid bare, these root-like plants run in all di- 
rections, interlacing and overlapping each other in all directions, but in no 
case affording proof of rising into stems of Sigillaria. The calcareous and 
clayey deposits contain fragments of Hght shells and spines, of a pearly 
lustre, w ith an occasional small Trilobite ; these have evidently been 
drifted, and quietly arranged in layers. JN^ext is a limestone of deep-sea 
origin, the bluest in the series, and highly crystallized. It rises in thick 
large blocks, with scarcely anj^ cleavage or natural cracks : its fossils are 
not numerous, but well preserved. jProducti have attained their largest 
size ; Crinoids are numerous. Upon this limestone rests a yellow sand- 
stone, twelve feet thick, — the base of a series of shales, sandstones, and 
thin limestones, interstratified with which are the Heagill coal-seams. The 
most important of these is immediately above the sandstone, with a clay 
shale floor of two or three feet thick. The upper beds of the sandstone 
and this shale are full of Stigmaria, then follows the coal-seam, from six to 
twelve inches thick. We may consequently infer, that after this sand- 
stone, with its clayey surface, became partially dry land, a rank vegetation 
of Sigillaria flourished, running their stigmarian roots deep into the clay 
and sand, till a sinking of the land brought the sea once more over it, and \ 
another deposit of clay shale six feet thick covered up the vegetable matter, ^ 
gradually to be compressed and mineralized. J^^ext above the clay shale is 
