Vol. 52.] ON THE UPPER PORTION OF DUNDRY HILL. 711 



Great Britain,' London, 1872, p. 209 ; and p. 318 gives the weight 

 of a cubic foot of Dundry stone. 



For analyses of the Dundry Freestone see 



Voelcker, Prof. A., Journal of the Bath and West of England 

 Agric. Soc, New Series, vol. vi. p. 223; Mem. Geol. Surv. vol. ii. 

 (1848) pt. 2, p. 688. 



IX. The Bajocian Denudation. 1 



Nowhere at Dundry Hill is the sequence of Bajocian strata com- 

 plete ; there is, even at the main-road quarries, where deposits have 

 been laid down during the greatest number of hemeroc, a break in 

 their sequence, so that the succeeding bed rests non-sequentially 

 upon the planed-off surface of the Ironshot Oolite. 



The portion of the Dundry strata which suffered least from 

 Bajocian denudation is that lying between the main road on the 

 west, and East Dundry and Rackledown on the east. AYestward 

 of this the Bajocian denudation has removed two important fossili- 

 ferous beds, namely, the Ironshot Oolite and the Witchellia-bed. 

 East of this area there are unfortunately no exposures until Maes 

 Knoll is reached, when the effects of denudation are very striking. 

 The Ironshot and all the limestone-beds which underlie it at 

 Dundry have been removed; and further denudation must have 

 taken place here in Bathonian time while deposition was going on 

 quietly at the western end of the hill, for at Maes Knoll there is a 

 conglomeratic bed of the date of the Garantiance hemera containing 

 shells of the Dumortierice hemera. 



Farther eastward, at North Stoke, a similar deficiency in the 

 stratigraphical sequence occurs, due in part at any rate to Bajocian 

 denudation. There the strata of the Garantiance hemera rest upon 

 about 8 feet of sands deposited during the Dumortierice hemera. A 

 similar non-sequence of deposits is found at the Barrow Hill, and 

 at Midford, near Bath. Then, in a northerly direction, from Bath 

 to Cheltenham, the Garantiana-bed is still found resting non- 

 sequentially on an earlier deposit ; but the gap in the sequence 

 decreases as the distance to Cheltenham lessens, until near that 

 town strata contemporaneous with the Witchellia-bed of Dundry are 

 once more found beneath the deposit of the Garantiance hemera. 2 



South-east of Dundry, however, some striking facts concerning 

 non-sequence of deposition were obtained. At Wellow, near 

 Radstock, 10 miles E.S.E. of Maes Knoll, the deposit of the Garan- 

 tiance hemera rests in some cases upon clay of a ^ve-falcifeH 



1 It should be noted that the term ' Bajocian denudation ' does not mean 

 denudation of rocks of Bajocian Age, which might have happened at any date, 

 but a denudation (of any rocks) which was effected during the Bajocian Age. 

 In the present case, so far as Dundry is concerned, the denudation doubtless 

 began towards the close of the Bajocian Age, and ended at the beginning — 

 before the second hemera — of the Bathonian Age. But there i9 evidence at 

 other places that it continued during the second hemera of the Bathonian Age. 



2 S. S. Buckman, ' The Bajocian of the Mid-Cotteswolds,' Quart. Journ. Gool. 

 Soc. vol. Ii. (1895) p. 416. 



