35© SECTIONAL TRANSACTIONS.— C. 



during their deposition indicated in detail by numerous local unconformities, 

 erosional features, boulder beds and slumping phenomena, and on the great 

 scale by very great variation in the thickness and character of the deposits. 

 The essential structure of the region was completed before the Permian 

 peneplanation. There is no evidence of more than a broad warping of the 

 north of England since Carboniferous times, with some considerable 

 faulting in the neighbourhood of the divisional line previously mentioned. 

 The present topography and drainage shows a remarkably close adjustment 

 to the Carboniferous tectonics. This fact, together with the low degree of 

 alteration of the rocks themselves, suggests that the Mesozoic cover has 

 never been of great thickness, and that it has done little more than protect 

 a pre-Permian topography of which the main lines are now re-emerging. 



Dr. R. G. S. Hudson. — Sudetic earth-movements in the Craven area. 



In the Craven area of Yorkshire, an area of Carboniferous sedimentation 

 in basin and on massif, the Mid-Carboniferous (Sudetic) orogeny consisted 

 of movements commencing in the Upper Visean and persisting to the end of 

 the Lower Namurian. These orogenic phases can be correlated with changes 

 in type of sediment action and vary both in character and in their relation to 

 basin, margin and massif. 



Early Sudetic movements have their major effect in the sedimentation 

 basin and resulted in general uplift followed by sharp folding along E.-W. 

 axes, best seen in the Skipton anticline where the main movement is of 

 Dj/Pj age. On the massif and on the reef-belt of the massif margin these 

 movements are indicated by intraformational breccias and conglomerates. 



Middle Sudetic movements show the transference of the main effect from 

 basin to the margin between basin and massif. They are of both Pi/P 2 and 

 Px/E! ages and resulted in down-folding and down -faulting of the basin 

 along the margin ; the former in front of the reef-belt and the latter (the 

 Mid-Craven Fault) at the back of the reef-belt, both being accompanied 

 by slumping, the formation of boulder beds and the rapid transgression 

 of the succeeding shales across the knoll topography and fault-scarps thus 

 formed. Probably the extrusion and slumping of the Scarlet lavas of the 

 Isle of Man margin are of this age. In basin and on massif these move- 

 ments are mainly expressed by change of sediment accompanied by local 

 non-sequences. 



Late Sudetic movements mainly affected the massif. Two movements 

 resulted in the unconformity of the Millstone Grit (Grassington Grit) on 

 the Yoredale Series and later the non-sequence between the Grits of Tan 

 Hill and the Mirk Fell beds below. These movements have only been 

 recognised in the basin by the thinning of the sub-Kinderscout beds 

 against the massif . 



This northward shift of the major effects of the various Sudetic move- 

 ments was continued during the succeeding Erzgebirgian orogenies and 

 resulted in the absence of the greater part of the Upper Namurian in North- 

 umberland and Durham. 



Mr. R. C. B. Jones. — The Lancashire coal-field between the Rossendale 

 anticline and Cheshire basin. 



The South Lancashire Coalfield has a general southerly dip which is much 

 interrupted by folds and faults. Its eastern limit is the Pennine Anticline 

 while to the west the Rossendale Anticline loses its influence and the 

 Carboniferous is faulted against the Triassic. The main coalfield is here 



