1855.] HULL ON THE COTTESWOLDS. 493 



the central districts of England, and the debris of the central di- 

 stricts over the more southerly portions of the country, another cur- 

 rent appears to have travelled westward, bringing the detritus of the 

 Chalk, and mixing it with the fragments of rock derived from North- 

 ern sources, and thus occasioning the prevalence of pieces of chalk 

 and chalk-flints in the drift of Nottingham, Leicester, and Glouces- 

 tershire. 



I have to record the occurrence, near the southern termination of 

 the Yale of Moreton, of three erratic boulders at the villages of 

 Bowl and Frescot, and on the same parallel as Cheltenham. They 

 are subangular blocks of Millstone Grit. Two of them are of a fine 

 variety, and the third of a coarser grain. The surfaces are uneven, 

 but I did not observe them to be scratched or polished ; these phse- 

 nomena being confined to blocks newly disinterred from diluvial de- 

 posits. The diameter of the largest is 3 feet, of another 2^ feet. 

 The transportation of these blocks can scarcely be referred to other 

 agency than that of ice, and it would therefore appear that bergs 

 occasionally wandered as far south in the Vale of Moreton as the 

 longitude of Cheltenham. Boulders have not been found south of 

 Tewkesbury in the Valley of the Severn. 



The " Boulders of Marlstone " mentioned by Mr. Gavey as occur- 

 ring at Mickleton Hill cannot be considered as erratic boulders in the 

 sense in which the term is usually received. These blocks of marl- 

 stone have evidently not been carried to a distance from their original 

 position, as the higher portion of Mickleton Ridge is composed of the 

 Marlstone formation. It would, I think, be for the advantage of 

 geological description were the term boulder confined to blocks of 

 rock which are supposed to have been transported from a distance 

 by the agency of ice. 



The higher portions of the Cotteswold Hills included between the 

 Vales of Moreton and Gloucester appear never to have been over- 

 spread by Northern Drift. The peninsula which terminates in Ebring- 

 ton Hill, has either been above the level of the glacial sea during the 

 deposition of the drift, — an improbable hypothesis, — or else its 

 scarped cliffs have formed a barrier to the transport of northern de- 

 tritus. In crossing the district from the western escarpment above 

 Cheltenham towards the east, we meet with no erratic pebbles until 

 we arrive at Stow-on-the-Wold, where in the Moreton Road, at an 

 estimated height of 500 feet, we find the following section : — 



ft. in. 



1 . Brown loam 1 



2. Soft white oolitic sand 5 



3. Pebble bed ; containing rounded grey and 



white quartz, black chert, flints, and grits, 



&c 2 



4. Reddish-brown loam 6 



South of Stow, the western limit of the Northern Drift is very well 

 defined. The line follows the western flank of the Bourton Valley, 

 thence trends along the southern bank of the Windrush River, nearly 



2 L 2 



