204 A. H. Cox and A. E. Trueman — 



from Yorksliire as a consequence of some regional movement ; the 

 results of the regional movement almost completely conceal the 

 results of any minor flexuring during that time. Attention has in 

 the past naturally been drawn to the larger lateral variations, with 

 the result that any minor or local variations superposed on the 

 regional ones have been overlooked. 



As remarked above, we have failed to accumulate sufficient 

 evidence to prove the occurrence of such local variations in the 

 formations considered as a whole. But so far as the records go, 

 they tend to confirm the results obtained by a critical examination 

 of subdivided zones, such as the aculum and tenuicostatum zones 

 detailed above. For example, the collected figures suffice to show 

 that the Upper Lias thickens in the Old Dalby syncline and in the 

 Bredon syncline. As regards the Lower Lias, there are evidences 

 of local thickening in the synclinal areas of Bredon and Badby. 

 As regards the Rhsetic there is again a thickening in the Bredon, 

 syncline, and perhaps also in the Old Dalby syncline. It seems 

 probable, therefore, that when sufficient data are available concerning 

 thicknesses of other zones and subdivisions, it will be possible to 

 trace the effects of the local movements in most of the divisions 

 between the Rhaetic and the Inferior Oolite, In this way it may 

 ])rove possible to separate the effects of local uplifts from those due 

 to regional movements involving widespread tilting with consequent 

 transgression or regression. 



(5) Evidence of Moveinents from post-Bathonian RocJcs. — We have 

 shown above that an examination of certain thin zonal deposits 

 appears to confirm the evidence of outcrop that folding was in 

 ]3rogress at intervals in Liassic time. Variations in thicknesses of 

 the major divisions yield some additional support. Taken in con- 

 junction with the results already mentioned as obtained by 

 Mr. Richardson, that local movements were taking place in Rhaetic 

 times along the same lines that were afterwards followed by Bajocian 

 movements, we find that there Avas gentler but almost continuous 

 movement along definite lines up to about the end of Bajocian time. 

 Then these particular movements appear to have ceased, for the 

 outcrops of the Bathonian and higher formations are but little 

 aft'ected. 



Nevertheless, it is still possible to trace the southward prolongation 

 of the folds beyond the area occupied by Bajocian rocks, because 

 movement along the same lines seems to have been renewed at certain 

 later periods, so that along the anticlinal lines denudation was 

 repeatedly at a maximum. Thus it is more than a coincidence that 

 along the southward prolongation of the Moreton anticlinal axis 

 the Lower Cretaceous Sands should at Faringdon suddenly come 

 to rest directly on the Corallian, while still further south, just where 

 the prolongation of the same line crosses the Vale of Pewsey uplift, 

 the Tertiarv beds overstep nearly the whole of the Chalk and come 

 into their closest proximity to the Upper Greensand, 



