460 Dr. Fitton's Additional Remarks. 



been denominated " iron sand," in those counties, and regarded 

 as the equivalent of the Hastings-beds, belongs in reality to the 

 greensand of the Isle of Wight : since the outcrop of trie chalk . 

 is continued without interruption through the tract just men- 

 tioned, with firestone in several places immediately below; and 

 a bed of clay is also represented as being continuous and pa- 

 rallel to the chalk throughout, — with the sands containing 

 " carstone," likewise in continuity, immediately beneath it : — 

 just as in the counties of Surrey, Kent, and Sussex.* 



It deserves inquiry, therefore, whether that part of the range 

 of sands passing through Oxfordshire, which shoots beyond the 

 general line to Shotover Hill, may not also belong to the green- 

 sand ; — the Tetsworth-clay in the same county, which has 

 generally been considered as the equivalent of the weald-clay, 

 being expressly identified by Mr. Smith with the gault of Cam- 

 bridgeshire. — In Buckinghamshire, the sand below the gault is 

 continued towards the north-east, from Thame to Woburn, but 

 the true nature of the portions which are most remote from 

 the gault seems more doubtful ; and some of these may possibly 

 be referable to the Hastings sands. — In Bedfordshire, the 

 sands adjoining the gault would seem to belong to the Shanklin- 

 beds; but the place of some detached portions of clay, in the 

 midst of the sands of this county, corresponds with that of the 

 weald-clay, and would consequently lead to the expectation ot 

 the true Hastings strata on the north-western verge of this 

 sandy district. — In Norfolk, the tract of sand which extends 

 with an irregular outline from near Downham to the sea at 

 Hunstanton, ranging nearly parallel to the chalk, and bearing 

 upon it several detached portions of blue clay with the cha- 

 racteristic belemnite of the gault (see Smith's map), seems to 

 be referable to the Shanklin sands. — In Lincolnshire from Spilsby 

 to near Barton, a similar remark may be applied. — And in the 

 south-east of Yorkshire, the long range of the chalk from the 

 north bank of the Humber to the shore on the south of Filey 

 Bay, is succeeded by sands, and these again by clay, the true 

 relations of which are still to be ascertained. 



An examination of the Ordnance Surveys, and of the geolo- 

 gical maps of the south-eastern counties, Wiltshire, Dorsetshire, 

 and Devon, in which the structure of the surface is more com- 



* I have had occasion to remark, that die local division of the beds in Mr. Smith's 

 county maps, is generally correct, in that part of the series which is at present under 

 consideration. — But unfortunately his names and colours are not always applied with 

 consistency ; and his erroneous identification of the green-sand of Kent with the Port^ 

 land sands, and of the Kentish rag with the Portland limestone, has caused his boundaries 

 of the strata also to be considered as erroneous, and thus diminished the usefulness of a 

 very valuable publication. The bed which I have traced in the text from Berks to 

 Cambridgeshire, under the name of gault, and which is so denominated in Mr. Smith's 

 county maps, is, in his reduced map of England, named oak trcc-day, and identified 

 with the weald-clay of Kent and Sussex. 



