86 Prof. Sedgwick on the Carboniferous Chain 



the most characteristic features of the Scar limestone. It is traversed by 

 fissures^ and hollowed out into caverns ; in one of which (Weathercoat Cave) 

 is a waterfall of no common beauty, and doubly striking- from the extraordinary 

 nature of the objects which are about it. 



Ascending thence to the top of the mountain, we cross the groups in 

 regular succession, and end with a series of thin-bedded, coarse grits, nearly 

 on the same parallel with the beds on the top of Penigent, and therefore pro- 

 bably subordinate to No. 15. of the general section *. 



The first millstone grit (No. 13.) makes a feature on all sides of the 

 mountain top, and the coal bed in No. 14. has been partially opened on its 

 north face. The coal bed in No. 10. (6.) has been worked in three or four 

 different places, and the group to which it is subordinate becomes regularly 

 expanded (though probably of rather less than its mean thickness) between 

 the twelve-fathom and the four fathom limestones. Here, therefore, ceases the 

 anomaly of the Ingleborough and Penigent sections already noted ; and it is, 

 as far as I know, the only great anomaly in the structure of the districts through 

 which the lines of section range. There is, however, a peculiarity (and it is 

 repeated on the east side of Great Colm) which deserves notice. The four- 

 fathom limestone all round this mountain is thicker than the twelve-fathom 

 limestone, one group being developed much beyond its average thickness, and 

 apparently at the expense of the other f. 



From Whernside the line deflects nearly due west (without producing- any 

 confusion in the details, as all the groups are very nearly horizontal), and 

 ranges by High Pike across the pass from Dent to Ingletcn];. The four - 

 fathom limestone, and the slate quarries (No. 8. c), form the top of the ridge; 

 and on the north-east side of it, is a succession of waterfalls over the bare 

 escarpments of all the groups, from the fourth limestone (No. 7.) down to the 

 beds above the black marble series. Through the middle portion of these 

 falls, runs a north and south vein (partly filled with calc-spar), producing a 

 downcast of eight or ten yards on its west side. I mention this for the pur- 



* The natural section is not good near the top of Whernside, the highest mountain of the whole 

 range ; but the top beds may possibly represent a portion of the 16th group of the general section. 



•j- This fact has sometimes induced me to suppose that the great calcareous escarpment near the 

 top of Ingleborough and Penigent was chiefly composed of the Jour-fathom limestone ; and that 

 some bands of shale and thin beds of limestone near its top, might represent the two superior 

 groups (Nos. 10. and 11.) in a very degenerate form. I mention this only as a mere conjecture. 



j In the southern and central portions of the principal line of section, the beds, though nearly 

 horizontal, incline on the whole a little to the north-east. The part of the section deflecting nearly 

 due west, from the top of Whernside over High Pike to Great Colm, is omitted in the accom- 

 panying figure (PI. VI. fig. 2.). 



