1855.] HULL ON THE COTTESWOLDS. 481 



and Stanley Hills, are capped by Oolite. The highest formation on 

 Dumbleton is Upper Lias ; and Dixon and Taddington Hills are 

 composed of Marlstone. The strata of Dumbleton and Oxenton 

 Hills are affected by faults which have doubtless contributed to 

 their preservation. The strata of the remaining outliers, however, 

 are not apparently faulted, and the immediate cause of their stability 

 appears to have arisen from the protection which was afforded 

 them by the relative position of Breedon Hill. 



The position of this principal outlier, with reference to the others, 

 and to the headland which terminates in Notting Hill, is nearly 

 N.N.W. ; and on each side, where no protection from the north 

 appears to have been afforded, the ancient sea has made a clean 

 breach, having excavated the Valley of Winchcomb on the east, and 

 denuded the Vale of Gloucester on the west ; it therefore appears 

 that Breedon Hill has acted the part of a breakwater to the area 

 south of it, moderating the action of the sea along that line of 

 country, from which circumstance, in conjunction with several others 

 hereafter to be noticed, it may be inferred that the destructive action 

 of the sea, whether in the form of northerly currents or as breakers 

 impelled by violent winds, has acted with greatest energy from the 

 north or north-west directions. 



Two other outliers known as Churchdown and Robinswood Hills 

 occur at the south-west extremity of our District. Churchdown is 

 unprotected from the north, and therefore its preservation cannot be 

 accounted for on physical grounds similar to those stated above. 

 That it has been preserved, while the strata which once surrounded 

 it have been swept away, is to be accounted for from the fact of the 

 thickness of the Marlstone capping its summit, and the degree of 

 hardness which this rock has attained. In that locality it was pro- 

 bably stronger than anywhere around, and hence it has resisted 

 more successfully the action of the sea. The thickness of the rock- 

 bed at Churchdown is 10 ft. 4 in.* ; and some of the bands are very 

 hard ; and, as far as I have been able to observe, there is no place 

 along the flank of the escarpment near Cheltenham where it is of 

 equal thickness or strength ; hence in that neighbourhood Marl- 

 stone platforms are both few and of small extent. The develop- 

 ment of the Marlstone rock may therefore be considered as fully 

 sufficient to have maintained the outlier ; and Robinswood Hill may 

 have remained standing from a similar cause, combined with the 

 protection afforded by the Churchdown outlier. 



Causes which have contributed to the preservation of the Head- 

 lands^ and the formation of the Valleys. — On viewing the Ordnance 

 Map, it will be observed, that the majority of the headlands project 

 in a northerly direction. (See fig. 1.) The elevated plateau between 

 the Vales of the Severn and of Moreton-on-the-Marsh is itself an 

 extensive headland, which (as I shall presently endeavour to prove) 

 formerly stood forth unsubmerged by the waters which deposited 



* See ' Murchison's Geology of Cheltenham,' edited by Messrs. Buckman and 

 Strickland, p. 39. 



