REPORT ON GEOLOGY. 
381 
of Cross Fell the lower series of the carboniferous limestone, 
locally termed Scar lime, is subdivided in like manner, and 
alternates with sandstone and carboniferous shale * ; the lime¬ 
stone decreasing and the coal beds increasing as the strata ap¬ 
proach the transition chains of the Scotch border. The coal 
measures occupying the great valle}* of the Scotch Lowlands on 
the north of these chains, are with great probability referred 
to the same lower series ; but this Scotch district has as yet 
been very imperfectly described. 
The immense faults and dislocations of our great northern 
coal-field have also received the fullest illustration in the Me¬ 
moirs above cited; and no geological subject can be considered 
more pregnant with fundamental information than this, for it is 
only by a careful and detailed examination of the phenomena 
attendant on these great convulsions that we can ever hope to 
be enabled to speculate satisfactorily on the causes which have 
produced them. Now in the Newcastle district we find the 
strata shattered at every two or three miles interval, with fis¬ 
sures extending to many leagues distance, and producing sub¬ 
sidences of occasionally not less than 140 fathoms, which, if 
they affected equally the configuration of the surface, would 
produce precipitous escarpments near 1000 feet high; yet is 
the actual level of the surface found absolutely uniform, and 
affording no trace whatever of the vast subterraneous distur¬ 
bances ;—a most striking proof of the vast mass of materials 
which must have been removed subsequently to their occur¬ 
rence. Here we remark one of those great problems for the 
* Thus in the two important groups just noticed (viz. the pcecilitic and 
carboniferous series), recent observations have enabled us to supply those great 
lacunae which previously occasioned the appearance of an abrupt transition 
(per saltum ) from one order of geological products to another totally different; 
the connecting links before missing are now restored, and seem to establish a 
graduated and continuous order in this most important portion of the geological 
series. Thus in the transition formations we see alternations of slate, coarse 
gritty grauwacke, and beds of entrochal limestone, often associated with seams 
of anthracite, and, according to Mr. Weaver’s late Memoir, with regular coal 
in the South of Ireland. In the carboniferous group we have precisely similar 
alternations, only that the limestone frequently prevails most in the middle re¬ 
gions, and the coal in the uppermost; the organic remains of the limestones ap¬ 
proximating very nearly to those of the preceding transition series. In the 
succeeding poecilitic group the organic remains still in many instances belong 
to the same class, and partake of the earliest type, although species of a more 
recent character begin to be introduced: the subjacent Pontefract sandstone 
(rothe todte) also exhibits a regular approximation to the coal grits. We have 
before seen how the graduation is continued from the magnesian limestone 
through the muschelkalk to the lias and oolite, and we shall hereafter learn that 
the same intervention of gradual links exists between the cretaceous and ter¬ 
tiary groups at Maestricht and in the eastern Alps. 
