1922 CHRONOLOGY 27 



Sequenxe I — Long Crendon, Buckinghamshire 



Table II, i — 10. Creamy Limestones, (Barrel Hill, i — 10) 

 II, 12. Sands (Barrel Hill 11, N.W. i) 

 13—18. Rubbly Beds (N.W. 2—7) 

 19 — 24. Glauconitic Beds (N.W. 8 — 11) 

 25. Lydite Bed (N.W. 12) 

 Thame Sands (N.W. 13) 

 Crendon Clay 



Beds I — II were exposed in the quarry at Barrel Hill, on the south 

 of the village. 



Beds 12 — 24 are exposed in pits at the north-west end of the village, 

 in a field to the right of the road to Oakley. Bed 12 is presumed to 

 join to Bed 11 \nthout gap and without lap, but this requires to be 

 proved. 



Bed 25 is also exposed there, and was pierced in well-sinkings on 

 the south side of the \'illage. 



The Thame Sands underUe the Lydite Bed, both to the north-west 

 and to the south of the village. They are exposed in a sandpit on 

 Barrel Hill and in various sandpits in and around Thame. They may 

 be supposed to represent the Shotover Fine Sands, while possibly the 

 Shotover Grit Sands appear in the top of them, locally, and somewhat 

 altered. There are large doggers towards the top of the Thame Sands, 

 according to Fitton (Trans. Geol. Soc. (2) IV, 1836, p. 283), showing 

 penecontemporaneous erosion and non-sequence, as one may interpret 

 his figures (p. 283, figs, i, 2). I have only seen large slabs of calcareous 

 sandstone (Thame, near Railway Station). Coming eastwards from 

 Shotover, these Shotover Sands are only feebly represented in the 

 western part of Wheatley Brickyard, petering out in the eastern part. 

 Further east towards Thame, after some interval, sands, presumably 

 Thame Sands, lie immediately beneath Gault Clay (Cf. Fitton, p. 282). 

 At Moreton the Lydite Bed was found in this position. 



Below the Thame Sands at Crendon is the Crendon Clay, shown in 

 the now-closed brickyard at the foot of Barrel Hill. It is presumably 

 equivalent only to the lower part of the Hartwell Clay of Hartwell. 



The Building Stone, Beds 3, 4, is seen to advantage in the quarries 

 of Haddenham parish, adjoining the road from Thame to Aylesbury. 

 Ammonites seen at Portland, though, of course, they could only be 

 superficially examined, suggest that this Building Stone of Buckingham- 

 shire was deposited during two hemerae. The Glauconitic Beds (19 — 24 

 of Table II) correspond more or less with the beds described by Fitton 

 at Barley Hill, near Thame, Oxfordshire (loc. cit., p. 282), a pit long ago 

 closed. But the identity of the locally-named " Barley Hill Blue Bed," 

 Fitton 's Bed 5 presumably, with the Building Stone of Long Crendon 

 (north-west) is not proved ; for Behemoth has not been yet found at 

 Crendon, and Glaucolithites has not been discovered among old Thame 

 specimens said to come from the Blue Bed. 



The position of Perisphinctes gorei, Salfeld, entered as a hemeral 

 term opposite Behemothan 9, must be considered as approximate onh*. 

 There are polygyral forms of gorei style in several beds both above and 

 below. Mr. E. Neaverson, F.G.S., obtained a fine collection of such 

 forms, reasonably supposed to have come from the Bugle Pit, Hartwell : 

 they may be from a bed not represented at Long Crendon. He points 

 out that the matrix resembles that of the Shotover Grit Sands. 



