92 Prof. Sedgwick on the Carboniferous Chain 



above them are the grits^ shales^, and coal bands of No. 14*; and the series, 

 though almost lost among the accumulations of peat earth, terminates, I be- 

 lieve, in the beds of the second millstone grit (No. 15.). 



Notwithstanding the constancy in the position of the several groups, there 

 are changes of mineral structure which, had we not so many terms of com- 

 parison, might lead to some confusion. Near the eastern end of this sec- 

 tion, the black marble beds (No. 3.) lose that mineral character which gives 

 them their chief value, and resemble the beds of the higher group (No. 3.); 

 and with these beds they might easily be confounded, as, in some places near 

 Hawes, the shales of No. 4. are wanting, and the sandstone beds of the group 

 are not more than twenty or thirty feet in thickness f. Near the same place 

 the shales of No. 8. become insignificant, but the micaceous, slaty beds are 

 well developed. 



Section from the top of JVhernside to the top of Shunner Fell ; mean bearing 



about N.N.E. J 



The line here ranges from Whernside into the higher part of the valley of 

 Dent, about five miles above the village (where the river runs upon the top 

 beds of the Scar limestone) ; thence over the Cross to Mosdale, and over 

 Cotter Fell to the top of Shunner Fell, without making any very great devia- 

 tions in its course §. 



The strata of Whernside have been already noticed, and the same groups 

 succeed each other in regular order on the side of the next mountain, where 

 however we may remark, that the four-fathotn limestone is of less, and the 

 twelve -fathom limestone of greater, than their average thickness ; just the con- 

 trary of what was observed among the groups of Whernside ; and another 

 instance of what was remarked before, — viz., that each of these two limestone 



* This coal bed is not worked, as it is only about eighteen inches thick, and is inferior in qua- 

 lity to the thirty-inch coal of Turna Fell, in the same range of hills, and only at a short distance 

 towards the north. 



t Further down Wensleydale these three groups of the general section (viz. Nos. 3. 4. and 5.) 

 probably lose all distinctive character, and appear as one group : for I have remarked, that in the 

 hills below Askrigg there are only Jive, instead oi^ six, distinct limestone groups, from the Scar lime- 

 stone (which is partially expanded in the lowest parts of the valley) to the twelve-fathom limestone 

 inclusive. Between Askrigg and Bolton Castle the whole system is intersected by metalliferous 

 veins, producing (like ordinary yaM/i*) contortions, upcasts or downcasts, and other disturbances of 

 the component strata. 



+ Plate VI. fig. 4. 



§ The Cross (a mountain of which the summit is sometimes called Naughtberry Hill) must not 

 be confounded with Cross Fell, the highest mountain of the carboniferous chain north of the Eden. 



