Morris — Ferruginous Sands of Buckinghamshire. 457 



a more or less thick deposit of coarse ferruginous sand, with inter- 

 calated bands, or irregular concretions of ironstone, for the ex- 

 traction of which this bed has been extensively worked in. many 

 places, and its general characters and contents more fully made 

 known. 



It was from these sands, in the neighbourhood of Leighton, that 

 the specimens of Cycadites Yatesii, described by Mr. Carruthers,^ 

 were obtained, associated with coniferous wood ; but no other fossils 

 have been met with to my knowledge, although near there — at 

 Linslade — casts of Niicula and other marine shells were found. In 

 a south-westerly direction these beds are not so thick, and are seen 

 capping the hill-tops, the intervening portions having been removed 

 by denudation. Thus, around Aylesbury, at Hartwell and Stone, 

 these sands overlie the Purbeck and Portland beds, but in a southerly 

 direction have been removed over a considerable area, until their 

 equivalents are again seen at the surface near Bishopstone, beyond 

 which they are covered by the Gault and Upper G-reensand ; these 

 again dip under the Chalk strata of the Chiltern Hills, which form 

 a portion of the fine chalk escarpment overlooking the country to 

 the north. The Upper Chalk is again covered by the Tertiary 

 strata, which in some places, as at Hampden, is a hard sandstone, 

 and silicious flinty conglomerate, identical with the so-called " Druid 

 Sandstone," or " Sarsen- stone," — very durable, and which has been 

 worked for building and road-stone, and largely used for the foot- 

 ways at Aylesbury, and in Hartwell grounds.* 



Dr. Pitton, in his able memoir, " On the strata below the Chalk,"* 

 carefully described the district around Hartwell, and gave a full 

 account of the sections then exposed, since which time (1827) some 

 sections have been enlarged, and other pits opened, so that a few 

 additional facts have been obtained, but which do not invalidate the 

 conclusions arrived at by Dr. Pitton ; thus, for example, the ferru- 

 ginous or Lower Greensand has been found to contain fossils, not 

 known at that time, from this locality. It is to these sands that this 

 brief notice is more especially directed, reserving for a futm-e time 

 some remarks on the Purbeck and Portland beds of this district. 



These sands and associated beds are well seen in four or five pits 

 around Hartwell, as well as along the Dinton road, and at the brick 

 works between that village and Haddenham, and also further west, 

 at Thame, Hazeley, and Brill. At the red sand pit, not far from the 

 Bugle Inn, an opening exposed about six feet of the sands overlying 

 a partly irregular surface of one of the Portland beds. The sands 

 are coarse, highly ferruginous, containing ochreous concretions, and 

 many quartz pebbles (which at one time were specially collected), as 

 well as many more or less rounded but large pebbles, consisting 

 of different materials, as quartzite, lydian stone, and others, evidently 

 originally derived from the older rocks. At the base of these sands, 



1 Geol. Mag., Vol. IV. p. 199. PI. IX. 



2 Blocks of this stone, known as Hampden stone, have heen extracted five or six 

 feet in length, and used as ornamental stones, or rude pillars, as at Hartwell Park. 



2 Geol. Trans., 2 eer., vol. 4, p. 285 et seq. See also iEdes ilartwclliaua. 



