590 MESSES. JUKES-BEOWNE AND W. HILL ON" THE LOWEE PAET 



There can be little doubt, however, that Stoke is the centre of a 

 shallow syncline (whether faulted or not), and that just as the beds 

 fell northwards along the strike to Whittington, so beyond that 

 place they rise northward to Marham, where the Melbourn Rock 

 attains a high elevation without being much in advance of the line 

 of strike. This northerly rise will account for the emergence of 

 the Gault and Lower Greensand from beneath the fen, and it will 

 also explain the carrying back of the outcrops so far eastward by 

 the valley of the Nar, which would otherwise seem to require the 

 agency of a fault. 



North of Marham and Narborough it is possible that the level of 

 the base of the chalk still continues to rise ; but if so, the diminution 

 in the thickness of the Lower Chalk keeps the normal level of the 

 Melbourn Rock nearly horizontal ; for though we do not possess 

 accurate information, the height of its outcrop at Marham and 

 at Hunstanton appears to be nearly the same, and these two places 

 are, we think, about on the true line of strike, viz. a north and 

 south line, without any appreciable trend to the west, such as would 

 appear if the line from Narf ord to Hunstanton were taken to be the 

 true line of strike. 



Thus the district we have described may be regarded, geometrically, 

 as consisting of three portions or blocks, the first extending from 

 Mildenhall to the Brandon river, the second from that river to the 

 Stoke river, and the third from Stoke to Hunstanton. The first 

 two of these blocks have received a slight tilt to the north, so that 

 the beds rise along the strike southwards, the third has an inclina- 

 tion in an opposite direction. 



It is evident that these faults and tiltings have a considerable 

 effect upon the surface-contours of the country, and it seems probable 

 also that the tilting of the first two blocks has a connexion with 

 the change of strike. In seeking for the cause of this change, we 

 must ask ourselves which is likely to have been the original strike, 

 the northerly strike of Norfolk, or the north-easterly strike of the 

 Midland counties? We think there can be little doubt that the 

 former was the original strike, imparted to the Cretaceous rocks by 

 the upheaval at the close of that period, and that the north-easterly 

 strike was the direction given to the escarpment by the disturbances 

 which produced the London and Hampshire basins. In other words^ 

 we hold that the influence of the synclinal curvature of the London 

 basin does not extend beyond the latitude of Mildenhall, and that 

 north of this the original strike of the Cretaceous rocks is preserved 

 with little alteration, and has not been affected by the disturbances 

 above mentioned. 



§ 6. Summary and Inferences. 



Gault. — With respect to the Gault we claim to have established 

 the following facts : — 



1. That the Gault can be traced through Norfolk from Stoke 

 .Ferry to Dersingham, where it thins out. 



2. That it is divisible into an upper and a lower portion, and 



