113 



believe that such was the case, because in my examinations 

 I have almost invariably seen that the Lower river Gravels 

 rest upon an even surface ; then it was that the Marine Shells 

 which have been found were deposited, an upheaval of the land 

 subsequently took place, and river action again began its work 

 on the Upper Gravels, forming the Lower Mammalian Drift. 



In correlating the Gravels of the Severn with those of other 

 rivers in the kingdom, it is necessary to bear in mind that there 

 is every reason to believe the same large amount of tidal action, 

 which is now so marked in the Severn estuary, formerly existed, 

 and which may account for some of the differences that appear 

 in these Gravels compared with the Thames and some other 

 rivers. The tide at Chepstow sometimes rises 48 feet ; at the 

 London Docks the average range is about 22, Liverpool 15, 

 Portsmouth and Plymouth 12, Bristol 33. 



TJie small sub-angular Oolitic Gh-avel which Mr. Hull considers 

 to be the remains of raised sea beaches, occurs in parts of the 

 Cotteswold range, always presenting the same character. 



It is met with at Standish, following the Coombe to Stocken, 

 opposite the Horsepools, at Cooper's Hill, Crickley, and Leck- 

 hampton ; and it is generally found at the foot of the Inferior 

 Oolite, or resting upon the Upper Lias Sands, (sometimes, as 

 at Leckhampton and NaUsworth, on coarse sub-angular Oolite,) 

 in all cases running up to a point where the Coombe is at a 

 considerable angle. It is composed of the Freestone of the 

 Inferior OoUte, without any Fossils or even recent Shells, and 

 my impression is certainly opposed to the opinion that it is a 

 raised sea-beach; I beHeve it to be attributable to frozen snow or 

 land ice, which, when the thaw set in, would slip down, carrying 

 with it the detritus of the Freestone, and is of the age when the 

 cHmate had become comparatively mild. The elevation varies 

 from 500 to 700 feet, but at Longford, near Nailsworth, it is 

 only 300; and, indeed, similar Gravel of yellower colour is 

 found in the holes or hollows on Cleeve HiU, at an elevation 

 of at least 900 feet. 



To suppose that the several beds are raised sea-beaches, we 

 must accoimt for the absence of marine Shells, and admit that 



