74 Rev. A. Sedgwick on the Geological Relations and 



An ideal loni^itudinal section through the Eppleton, lletton, and Ellemore 

 coal-pits will assist in explaining this statement. (Plate V. fig-. 3.) Its best 

 illustrations may, however, be derived from the magnificent sections on the 

 banks of the Nid near Knaresborough. Under the castle the inferior sand- 

 stone is seen at the base of the cliff supporting- a lofty precipice of yellow 

 limestone. A little way below, the sandstone disappears, and the limestone 

 descends to the bed of the river. But a few hundred yards below the second 

 bridge, the plane which separates tiie two formations rises above the level of 

 the river, makes a succession of rapid undulations, and lifts the beds of lime- 

 stone to the top of the escarpment. Again, this plain descends below the bed 

 of the river, and again (below the third bridge on the Ribstone road) rises 

 in an irregular arch, and passes through the middle of a precipice, the higher 

 part of which is composed of yellow limestone, the lower part of the lower red 

 sandstone. 



3rd. The lower red sandstone appears in some places to have undergone 

 considerable degradation prior to tlie deposition of those beds of limestone 

 which now rest upon it. I have before alluded to the thin beds of an imperfect 

 conglomerate, which in a few places (for example, Maltby, Bramham Moor, 

 the escarpment west of Kirk Deighton, one or two of the sections near Knares- 

 borough, and the cliff under Tynemouth Castle) separate the yellow limestone 

 from the inferior sandstone. They seldom contain pebbles brought from any 

 great distance, but most frecjuently exhibit a kind of recomposed rock, con- 

 taining fragments of yellow limestone and siliceous sand, held together by a 

 more or less pure magnesian cement*. These phainomena seem to prove, 

 that the interval between the formation of the lower red sandstone and the 

 deposition of the lower beds of magnesian limestone was not one of complete 

 repose, but that the continuity of the deposits was partially interrupted by 

 mechanically disturbing forces. If this reasoning be correct, we might expect, 

 without any more evidence, to find traces of those degradations to which I 

 have alluded, and a consequent partial want of conformity between the sand- 

 stone and the lower beds of magnesian limestone. This local want of con- 

 formity is well exhibited in the quarry on Bramham Moor, to which I have 

 before referred ; in the sandstone quarries west of North Deighton, and in 

 one or two of the sections below Knaresborough. (See Plate VI. figs. 2. 3. 

 4. 5. & 6.) Some of the phcenomena near Knaresborough may be explained 

 by the false bedding of the sandstone, and the supposed original irregularity 

 of its upper surface. But there are some sections which I think set such an 



* For examples of actual sections in which this conglomerate appears, see Plate VI. figs. 1. 2. 

 3. & 5. 



