Vol. 68.] siiccESsioisr iisr the noeth-west of England. 481 



(1) The Yoredale type. — This type is limited to the Shap 

 and Pennine Districts. 



Lithology. — The beds resemble generally the Yoredale rocks 

 of the type area in Wensleydale, and also the well-known develop- 

 ment of these beds on Ingleborough and Penyghent. They consist 

 of alternations of limestones and sandstones, with subordinate 

 shales and occasional thin coal-seams. The limestones vary in 

 number in the two districts : eleven distinct beds being recognized 

 in the Shap area, and fifteen in the Cross-Pell range. Occasionally 

 one or two of these may unite to form a single thick limestone, 

 as in the case of the Brackenslack and Maulds-Meaburn-Edge 

 Limestones, which unite in the northern portion of the Shap 

 District to form the Lowther Limestone. The exact correlation 

 of the individual limestones of the two districts is not, however, of 

 importance, except in so far as they contain similar faunas. The 

 rocks in the two districts appear to have been deposited in direct 

 continuity, and are only now separated as a result of the denudation 

 which has taken place on the upthrow side of the Pennine Fault. 

 The limestones are, as a rule, dark, impure, and ferruginous ; 

 they are frequently crinoidal, while many of them are markedly 

 bituminous. Some are argillaceous, and these show a tendency to 

 nodular and concretionary structures. The lower beds are usually 

 fairly fossiliferous in both areas, but the fossils are seldom well- 

 preserved. In the Shap District the higher beds are almost barren, 

 and are locally dolomitized and impregnated with silica and 

 haematite. In the Pennine District the corresponding beds are 

 much richer in fossils. The sandstones are seldom fossiliferous, 

 except in the neighbourhood of Middleton-in-Teesdale, where one 

 bed occurs near the summit of the Yoredale Series crowded with 

 casts of Sjpirifer cf. hisulcatus. The shales are quite subordinate 

 in the Shap District, and are seldom exposed. In the Pennine area, 

 however, several beds of black shale occur, which are often crowded 

 with bryozoa and small brachiopods. 



The Yoredale Beds may, for convenience of description, be 

 considered under two divisions : — 



Bands. 

 Upper, with Dibunophjllummuirheadi I 'Botany Beds.' PMlllpsastrcsa Ba^nd. 



" 1 Froductiis-edelhurgensis J '^ * 



Lower, with Lonsdalia floriformis ( Productics-c^. giganteus Band. 



and Cyathophyllum regium. \ Nodular Girvanella Bed. (At the base.) 



The lower division with Lonsdalia floriformis includes 

 all the beds, from the lowest sandstone to the base of the Maulds- 

 Meaburn Limestone of the Shap District or the Jew Limestone 

 of the Pennine Escarpment (the Hardraw-Scar Limestone of 

 Wensleydale). All these beds lie above the Knipe-Scar Limestone 

 and the true Melmerby-Scar Limestone ; but one or two of the 

 lower limestones are occasionally included in the term Melmerby- 

 Scar Limestone on the maps of the Geological Survey, in such wise 



a. J. G. S. No. 272. 2 n 



