Yol. 68.] STJCCESSION IN THE NORTH-WEST OF ENGLAND. 535 



Comparison with the Type Districts. 



The chief noteworthy features are : — 



1. The absence of the Shap Dolomite Series below the Thysanophyllum Band, 



that is to say, of practically the whole of the Athyris-glahristria Zone : 

 a fact which points to the submergence of the area now occupied by the 

 northern portion of the Pennine Chain, at a considerably later date than 

 the Shap and Ravenstonedale Districts. . 



2. The presence of a series of fossiliferous mudstones and pebble-beds at the 



base of the succession, overlain by barren sandstones. These represent 

 all the beds from the Tliysanox)hyllum Band up to the middle of the 

 Nematophylhim-minus Sub-zone. 



3. The fuller development of the Yoredule rocks, which in the Middleton 



District approximates to the normal development of this series in 

 Wensleydale. 



4. The presence of a series of impure cherty limestones and calcareous shales 



(the Botany Beds), which occur high up in the Millstone Grit Series 

 of the Greological Survey map, and contain abundant remains of Bibuno- 

 phylhim muirheadi and PhilHinastrcBa radiata, associated with a fauna 

 which closely resembles that of the Cyathaxonia Beds of D3 in Derbyshire. 

 0. The presence of an intrusive sheet of dolerite, the Whin Sill, which has 

 altered the rocks locally to such an extent, that the correct detei-mination 

 of the fossils in the beds in contact with it is often rendered impossible. 



The Basement Series. — These beds are best exposed in the 

 neighbourhood of E,oman Fell, and the whole series is mapped by 

 the officers of the Geological Survey as the ' Roman-Fell Beds.' ^ 

 On the Geological Survey map, however, a patch of pebble-beds 

 which occurs on the west side of Roman Fell is separated as an 

 underlying series called ' Basement Beds ' (red conglomerate). 



It is extremely doubtful, however, whether the conglomerates 

 seen on Roman Fell itself really belong to the same series as the 

 fossiliferous grits and pebble-beds which crop out east and south 

 of Roman Fell. If they do, they must certainly lie below these 

 latter beds ; but it is much more probable that they represent an 

 older series, and are contemporaneous with the Polygenetic Con- 

 glomerate of the Sedbergh and Ullswater Districts : as, however, 

 they have yielded no fossils of Carboniferous age, they need not be 

 further discussed in detail. One word, nevertheless, may be said as 

 regards their relation to the fossiliferous basement series which will 

 be next described. The Roman-Fell Beds are coloured as Basement 

 Carboniferous on the Geological Survey map, and are shown passing 

 conformably up into the Melmerby-Scar Limestone Series of Long 

 Fell on the east ; this mapping does not appear to be correct, as one 

 fault, at least, separates Roman Fell from the Carboniferous Lime- 

 stone Series of Long Fell. This fault, which is marked by a row 

 of potholes (fig. 3, p. 536), passes close to the old sheepfold nea:r the 

 summit of the col between Roman Fell and Long Fell. From the 

 top of the col it runs nearly due south towards the Druid's Temple, 

 where it apparently joins the main, or outer, Pennine Fault, 

 There can be no doubt regarding the existence of this fault, for 

 it brings the Bryozoa Band (B, fig. 3) on the east, which crops out at 

 a height of 1750 feet, below the level of the highest beds of the 

 Roman-Fell Conglomerate on the west, which rise to 1946 feet O.D., 

 ^ New Series, Sheet 31 (Brough-under-Stainmoor). 



