508 PROF. H. A. NICHOLSON AND MR. J. E. MARK ON 



It has been gencrallj' recog-nized that this list indicates the 

 Coniston-Li rues tone age of the deposit. JS^evcrtheless, unequivocal 

 Duf'ton Shales are found only one-third of a mile away in a stream 

 between Keisley and AVharleycroft, and probably approach close to 

 the limestone. 



We believe that the Keisley Limestone may have been thrust in 

 a north-easterly direction for some distance, and that the limestone 

 bands have been thickened by folding during this process, whilst 

 the shales have been to a large extent squeezed out. On the other 

 hand, the Dufton Shales have probably had their argillaceous mem- 

 bers largely repeated, and the limestones pulled out into lenticular 

 masses. This seems to us the mode of explaining the great dif- 

 ference in the lithological characters of two deposits occurring close 

 together and containing fossils of the same age, which accords best 

 with the observed facts, though before finally accepting it we 

 would advocate a closer study of similar lenticular masses of lime- 

 stone which occur elsewhere, and, so far as we are aware, alway& 

 in disturbed districts. 



Another block occurs to the south of the one just described, and 

 is terminated by a fault on the S.W. flank of Roman Fell, east of 

 the farmhouse of Fell Dikes. It is also about two miles long, and 

 is remarkable chiefly on account of the interesting development of 

 the '* CWona-heds '' shown on the western slopes of Eoman Fell, 

 which have been noticed by Mr. Goodchild *, who rightly records 

 the existence of Lower Bala fossils in that locality. These '■'■Oorona- 

 beds '' are situated above the rhy elite of the flanks of Roman Fell, 

 and doubtless pass under the Dufton Shales of the Hilton Beck 

 Smelt Mill. Three principal subdivisions are noticeable in Lycum 

 Sike and the streams to the south. Resting on the rhyolite are 

 pink ashes with OrtJiis testudinaria, Dalm., in abundance. Above 

 these are pink shales with fine examples of Trematis corona, Salt., 

 and Lingula tenv.igranulata, M'Coy, whilst the highest beds seen, 

 which abut against the Pennine Fault, are vevj calcareous ashy 

 beds crowded with gasteropods and lamellibranchs, and containing 

 occasional specimens of the two above-mentioned horny brachiopods. 



The pink staining noticeable in these rocks is no doubt due ta 

 percolation from the overlying conglomerates. 



One more block is found south of this : a cross-fault once more 

 brings up a mass of rhyolite, which runs southward for one third 

 of a mile, when it is cut off at HowgiU Fold by the great fault 

 which brings down the Carboniferous conglomerates as vertical 

 beds converted into quartzite (see Appendix I.). 



This block is chiefly noticeable on account of the re-appearance 

 of the Knock Pike-Flagdaw Fault from under the conglomerate, sa 

 that a small triangular patch of leaden-grey shales appertaining to 

 the rocks of the eastern side of the Inlier is seen on the hillside 

 north of HowgiU Fold. 



The last block to be noticed occurs in the extreme north of the 



* Proc. Geol. Assoc, vol. xi. (1890) pp. xcv & 263. 



