1851.] SEDGWICK — PALEOZOIC ROCKS OF WESTMORELAND. 53 



I have sketched in from memory, and in accordance with one of the 

 sections given by Phillips*. It is not my object to describe this part 

 of the great fault. Near Austwick it may, I think, be considered as 

 separated into two branches ; the main branch ranging by Giggleswick 

 Scar and Settle ; the other, and diverging, branch ranging up the 

 Austwick valley, and then striking nearly E. and W., crossing the 

 Ribble (as above indicated in section fig. 6) near Stainforth, and 

 thence bearing towards Malham Moor. If I might hazard a con- 

 jecture, I should say that on this line of fault are probably brought 

 out the slate-rocks which appear between Malham Moor and Kilnsea. 



One fact more requires notice before I conclude the description of 

 the section. The grear spur of Scar-limestone that descends towards 

 Austwick is not so high as the top of Moughton Fell, but is in part 

 of its range as high as, or higher than, the junction of flagstones and 

 calliards of that Fell with the overlying limestone. Now, not only 

 on the sides, but on the very top of the Austwick ridge f, there lie 

 scattered a series of large blocks (see fig. 6) which exactly resemble 

 the hard grits and calliards that break out under the crest of 

 Moughton Fell. These blocks are not in an advanced state of de- 

 composition ; they clink under the hammer, and they are generally 

 angular, and not at all water-worn. If we leave the hills and cross 

 the comparatively low carboniferous tract that descends towards Ben- 

 than, we may see hundreds of erratic blocks of exactly the same 

 character. How have they been transported ; and, especially, by 

 what power have they been perched on the calcareous ridge north of 

 Austwick ? That enormous masses of limestone and slate have been 

 washed away, and that the Scar-limestone of Penygent, Ingleborough, 

 Moughton Fell, &c., were once continuous, hardly admits of a doubt ; 

 but of the vast masses of matter that were carried away when the ' 

 valleys were excavated nearly into their present forms, we have no 

 vestige whatsoever. All the alluvion of the valleys, and all the 

 erratic drift above alluded to, belong not to an ancient, but to a very 

 recent period. 



If it be allowed, that during the glacial period the land was de- 

 pressed about 1500 feet below its present elevation, the high calca- 

 reous chain of Yorkshire may have existed as a series of ridges and 

 islands surrounded by barriers of ice. Year by year the icy barriers 

 may, during summer, have carried off portions of the rock and 

 dropped them at a distance ; and while the land was rising to its 

 actual height, it was quite natural, on this hypothesis, that the float- 

 ing ice-rafts, and the loads they carried, should be stranded on a 



* Trans. Geol. Soc. 2 Series, vol. iii. PL I. section F. 



t Prof. J. Phillips has mentioned the occurrence of the Calliard blocks on Long 

 Scar on the north of the faulted region. From measurements Prof. Phillips has 

 lately made, he finds that Long Scar is higher than the Austwick Scar and much 

 above the Calliard range ; its summit is rather less than 1 400 feet above the sea. 

 Some of the blocks still remaining are at an elevation of 1260 feet above the sea. 

 The summit of Moughton Fell is 1404 feet above the sea. The surface of the 

 southern limestone band above Austwick and Clapham Lodge (where the blocks 

 are abundant) is about 850 feet above the sea. I am indebted to Prof. Phillips 

 for these measurements. 



