Inverted Alass of Upper Cretaceous Strata. 61 



coarser sediments soon gave place to the succeeding clay. Locally, 

 as we have noted at one of the pits at Miletree Farm, the clay 

 immediately above the bottom bed contains pebbles, a sign of con- 

 tinued current-action at that spot. Evidence for the existence of 

 an overlap of interrujotus or later date has been referred to by 

 Dr. A. Morley Davies,^ while Professor Kilian has pointed out the 

 widespread character of the transgressive movements proved to 

 have occurred in Upper Gault time.''^ 



Another section in this neighbourhood is less easy to interpret. 

 This is the brick -pit, situated 1,100 yards to the southward of Harris's 

 Pit (No. 3), from which Jukes-Browne recorded a number of Upper 

 Gault and Lower Gault fossils.^ There was at one time an exposure 

 here showing 10 feet of clay with a seanl of nodules about the middle, 

 from which the fossils were said to have been obtained. This pit 

 has long been disused and is now so overgrown and flooded as to 

 give no information. Mr. Lamplugh used Jukes-Browne's account 

 of this exposure in support of the contention that the clay at Harris's 

 Pit above the brachiopod-bed is of Lower Gault age. Indeed, this 

 seems to have been the only item of evidence which he was able to 

 bring forward as the basis of the following important statement : 

 " We must therefore conclude that the overlying clay in the sand- 

 pit sections represents Lower Gault, and that the fauna of the 

 calcareous masses is of earlier date." * 



Now it is clear that if the fossils recorded in Jukes-Browne's 

 list were correctly identified, the nodule-bed in which they occurred 

 does not belong to the Lower Gault ; it must be of rostratus age. 

 If the Lower Gault fossils truly came from the same bed of nodules 

 they must have been derived ; if they did not come from that stratum, 

 then it is conceivable that beds of interniptus-age are present at 

 this locality, overlain by the unconformable rostratus Gault. Yet 

 the knowledge gained from the sections already described renders 

 it improbable that a 10 ft. section would include both these faunas. 

 No nodule bed similar to that described by Jukes-Browne has been 

 seen in any of the sections examined by us, and we are unable to 

 test the value of his record. It is possible that the bed is present 

 in the concealed part of the section in the Upper Gault 300 yards 

 north of Shenley House (No. 9) ; the character of the fossils recorded 

 by Jukes-Browne is quite in keeping with such a position, corre- 

 sponding with Bed IX at Folkestone. 



The examination of the undisturbed Gault east and west of 

 Shenley Hill shows that the higher beds of the Upper Gault, which 

 constitutes the main mass of the hill, stand up as an outlier, isolated 



1 A. M. Davies & J. Pringle, " On two deep Borings at Calvert Station 

 (North Buckinghamshire) and on the Palaeozoic Floor north of the Thames " : 

 Quart. Journ. Geol. Soc, vol. Ixix, pt. ii, 1913, p. 338. 



"^ W. KiUan, Lethea Geognostica, II. Das Mesozoicum, Bd. iii, Abth. i, 

 " Unterkreide," Lief, i, 1907, pp. 61-125. 



* A. J. Jukes-Browne, op. cit., 1900, p. 285. 



* G. W. Lamplugh & J. F. Walker, op. cit., 1903, p. 246. 



