GEOLOGY 



was marked by minor earth movements temporarily raising one area and 

 depressing a closely contiguous one. Therefore, in the important search 

 for coal underneath the red rocks, it will long remain uncertain what 

 particular member of the Carboniferous System will be encountered or 

 what its thickness will be. 



Differences in the distribution of the fossils have been taken to 

 mark out the Carboniferous System into an Upper and a Lower portion, 

 but authorities are at variance as to where the divisional line should be 

 drawn. The plants and fishes indicate a change at the top of the so-called 

 Yoredales (Pendleside Series) of Staffordshire ; the mollusca on the 

 other hand show no such differences, but many of the marine forms con- 

 tinue from the base of the Pendleside Series to high up in the Coal- 

 measures. In a short sketch however it is out of place to enter into a 

 discussion of this vexed question ; whatever floral and faunal changes 

 may ultimately be found to differentiate the various stages, stratigraphi- 

 cally, as Ramsay always contended, the Carboniferous System can be 

 regarded as a unit. 



CARBONIFEROUS OR MOUNTAIN LIMESTONE 



The celebrated scenery of Dovedale and the beautiful valley of the 

 Manifold owe their charms to the rocks of this important sub-division. 

 Excavated into deep gorges and pinnacles of fantastic shapes, enhanced 

 by the soft verdure of peculiar vividness and the delicacy of outline 

 of numerous limestone-loving plants, threaded with caves and mysterious 

 underground water channels, the Carboniferous Limestone country ever 

 exerts a strong impression on the mind. 



The Carboniferous Limestone, which, as previously mentioned, only 

 occurs in the north of the county, consists of an undivided mass of pale 

 grey, white or blue limestone of great but undetermined thickness. The 

 quality of the rock varies from place to place ; that at Caldon Low in the 

 Weaver Hills is of exceptional purity, and thousands of tons are annually 

 quarried for use as a flux in the iron furnaces of Staffordshire and for 

 the production of alkalies and lime for various purposes. The pipes and 

 hollows traversing the rocks have also yielded large quantities of copper 

 and lead, the famous mines at Ecton being considered, toward rhe com- 

 mencement of the eighteenth century, to be the richest copper mines in 

 Europe. 



The outcrop of limestone in the Weaver Hills and the Manifold Valley 

 forms a southerly extension of the large massif of the Carboniferous Lime- 

 stone of Derbyshire, and similarily owes its existence to a strong anti- 

 clinal uplift bringing it to the surface from under the denuded cover of 

 the shales and grits of the Pendleside Series. The convolutions visible 

 in the Staffordshire lobe of the Derbyshire limestone west of the Dove 

 are doubtless continued, underneath the folded Pendleside strata, to the 

 west of the main limestone outcrop in the Weaver Hills. This is shown 

 to be the case by the small mass of limestone which comes to the surface 



7 



