GEOLOGY 



locality of the royal residence. These sands, according to Mr. Lamplugh, 

 may possibly be of an estuarine character ; they are current-bedded, and 

 they contain fragmentary plant-remains and pyritous nodules with wood. 

 They occur at Downham Market, and may be seen in pits on Grimston 

 Common, on Sandringham Warren, and in the railway-cutting at 

 Wolferton. The overlying clayey beds, termed by Mr. Lamplugh the 

 Snettisham Beds, have been worked for brick-making at Dersingham, 

 Snettisham and Heacham. They form a belt of moist ground, the 

 clays throwing out springs from the overlying sandy division. 



Northward from Heacham the Snettisham Beds have been traced 

 to the foreshore beneath the Carstone at Hunstanton, where the clays 

 seen at low tide were formerly thought to be Kimeridge Clay. South of 

 Dersingham this clayey division thins out, and its place is taken by an 

 irregular band of gritty ironstone containing obscure casts of marine 

 fossils. This ironstone, or ragstone, caps the Sandringham Sands on 

 Sandringham Warren and for some distance southwards. The division 

 is regarded by Mr. Lamplugh as a marine clav which was formed 

 somewhat rapidly. Among the fossils, which occur in nodules of iron- 

 stone and clay-stone, are Pecten cinctus, P. orbicularis, and species of 

 Cardium, Pleuromya, Trigonia, Crioceras and Belemnites, which suggest 

 correlation with the Tealby Limestone of Lincolnshire. Leaves of plants 

 also occur. Above this clayey division, or its equivalent ironstone, is 

 the Carstone. It is the chief building-stone of Norfolk : a brown friable 

 rock known as ' Gingerbread Stone,' which is largely quarried and hewn 

 into shape at Snettisham, and was formerly worked at Middleton and 

 other places. Small pebbles of lydite or chert are conspicuous in the 

 rock at Hunstanton, and stone of this character was in old times 

 fashioned into querns. At Hunstanton, there are found in the base of 

 the division phosphatic nodules and also concretionary masses of hard 

 grit yielding Ammonites deshayesi, Perna mulleti, and other fossils suggestive 

 of the Atherfield Clay of southern counties. Black phosphatic nodules 

 and fossils have also been found between the top of the formation and 

 the base of the Gault at West Dereham, where formerly they were dug. 

 The fossils resemble those of the base of the Folkestone Gault. In mass 

 the Carstone may represent the Hythe, Sandgate, and Folkestone Beds of 

 the south-east of England.' It was probably deposited in a somewhat 

 deeper sea than the Snettisham Beds, as indicated by its wide extent and 

 uniformity. 



The Lower Greensand where exposed at the surface forms dry 

 heathy commons and warrens, with occasional tracts of woodland, and 

 the land rises to about 120 feet. The soil is deep and sandy, and 

 sometimes crimson or purplish in colour. That of the lower sands can 

 hardly be called fertile, but a better soil is furnished by the Carstone. It 

 is a water-bearing formation, but it has yielded several ferruginous or 

 chalybeate springs, one of which, formerly of local repute, occurs at 

 Gaywood, near Lynn. Ochre has been worked at this locality, and 



* G. W. Lamplugh, notes in Geology of the Borden of the Waih, pp. 16-25. 



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