THE NORTH-EAST OF ENGLAND. 535 



brought about by the peroxidation of the carbonate by carbonic 

 anhydride, or by the conversion of the protoxide into the hydrated 

 peroxide by access of oxygen introduced in water finding its way 

 from above along the joints. In the three lowest feet of these beds 

 are (locally) incorporated three minor brecciated seams. At the 

 base of all comes a breccia varying in texture from a fine siliceous 

 sandstone or grit a few inches thick to a coarse and massive brecci- 

 ated rock 4 feet thick. Its upper surface frequently exhibits beauti- 

 ful gently swelling ripj)le -marks. Its contained fragments are 

 plainly seen to be largely derived from the fine ferruginous red and 

 yellow coal-shales, the sandstones, and ironstones of the neighbour- 

 hood ; there are also angular or subangular fragments of slate, 

 quartz, quartzite, &c. The fragments arc stuck-in confusedly at all 

 angles. The breccia, as also the overlying sandstones and lowest 

 Magnesian Limestones, contain many geodes lined with calc-spar 

 and iron pyrites. 



It will be seen that these sandstones, which have a marl-slate 

 facies and horizon, have but locally this character. Going south, in 

 a couple of miles they thin out altogether, and the breccia comes up 

 against the base of the degraded and dying-out Magnesian Lime- 

 stone ; while, on the other hand, as we go north and north-east 

 to "VVatnall, Bestwood, Linby, Annesley, Kirkby, Skegby, &c, they 

 pass into a series of shales increasing in thickness, with subordinate 

 bands of fine-grained sandstone and compact limestone. These beds, 

 from their close resemblance in colour and texture, have in many 

 instances been taken for coal-measures, and mapped accordingly. 



Eeturning to our main section, we find that the breccia rests in a 

 series of very gentle undulations on a planed-off surface of coal- 

 measure shales, sandstones, &c. (d 5 ). These latter beds dip in a 

 north-easterly direction, at an angle of fully 15° (but, as the railway 

 section is there running about NT.E. by E., the full dip is not exhibited 

 in the face of the cuttings). At one point a fault of unascertained 

 throw crosses the line, affecting coal-measures, but not Permians. 



Hence it will be observed that the unconformability between the 

 Coal-measures and the Permian is most pronounced. 



This is, I am aware, nothing new : it was a long while ago 

 pointed out by Sedgwick ; and colliery observations have rendered it 

 a matter of notoriety in the Derby-Xotts-Yorkshire coal-field : but 

 never before has there been in this district such a splendid above- 

 ground verification of the view that an enormous lapse of time 

 intervened between the close of the Coal-Measure and advent of the 

 Permian epoch in England, accompanied by the elevation and fold- 

 ing of the strata, not only along east and west (e. g. Pendle and 

 Cheshire anticlinals), but also north and south (e. g. Pennine) axes, 

 and by the sketching-out of the great coal-basins by denudation. 



The general tendency of the breccia (at base of Permian) to expand 

 westwards, and the occasional presence, according to Sedgwick, of 

 Mountain-Limestone pebbles therein, seem to indicate the existence 

 of a barrier of high ground, and perhaps also the exposure of the 



