216 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



grit ; while all tlie lower parts (commencing about a mile below the 

 village and to the west of the great transverse Craven fault) are com- 

 posed of the three groups of older rocks, above mentioned, which are 

 sometimes highly inclined and contorted. A great fault runs down 

 the valley of Dent, and a similar fault runs also down the valley of 

 Sedbergh, in consequence of which the Conistou grits (the most 

 striking of the older palaeozoic rocks of the neighbouring country) are 

 repeated at the north end of Middleton Fells, and at the south end of 

 Howgill Fells ; as may be illustrated by the accompanying section. 

 These faults and flexures do not at aU aflPect the Carboniferous series, 

 and evidently took place before the period of the Old-red-sandstone. 



s.s.w. 



S. end of Mid- 

 dleton Fells. 



Fig. 1. 



N.N.E. 



1 . Coniston limestone and shale. 



2. Conistou flags. 



3. Coniston grits. 



4. Ireleth slates (=Wenlock). 



The great Craven fault, on the contrary, took place, for reasons 

 stated in former papers, after the Carboniferous rocks were complete, 

 and just before the period of the New-red-conglomerates. It crosses 

 the valley of Dent nearly at right angles to its direction, and pro- 

 duces a singular effect on the whole features of the neighbouring 

 country. In some places the carboniferous and the older palaeozoic 

 rocks are separated by deep valleys, excavated nearly on the line of 

 the great Craven fault, and these valleys are not unusually much 

 filled with drifted matter which conceals from view any junction of 

 the older with the newer Palaeozoic series. In other situations 

 (especially on both sides of the valley of Dent, and thence dovm Bar- 

 bondale) the two systems are seen to abut, one against the other ; 

 being simply divided by the broken, and often nearly vertical, masses 

 of carboniferous limestone which mark the range of the Craven fault. 



In former papers I have described in sufficient detail the junction 

 at Helm's Gill on the north side of the valley of Dent, and I vdll 

 now shortly notice the corresponding phsenomena on the south side 

 of the valley where the two systems are seen (at the head of the pass 

 leading from Dent to Kirkby Lonsdale) to abut one against the other. 

 The general facts may be illustrated by the following, partly ideal, 

 section (Fig. 2). 



There could be no reasonable doubt that the groups of this sec- 

 tion must be identical with those of Helm's Gill, which commence 

 with the Coniston limestone ; but the lowest beds (No. 1) are so ill 

 exposed, or so much displaced by ancient land-slips, that I had not, 

 during former visits, been able to trace distinctly the Coniston beds 



