Geologists' Association. 429 



grits, the white chalky beds attaining their greatest thickness in the 

 cliff under the lighthouse. Commencing at the south-west point, 

 where the cliff rises from the lower ground, the attention of the 

 party was first directed to the bed of drift-clay, containing pebbles 

 and boulders of different rocks, as dolerite, limestone, flint, Eed 

 Chalk, etc., abutting against and overlying the ferruginous rock 

 for a short distance. This latter rock, which forms the base of the 

 cliff, is known to repose upon the Kimmeridge clay below, which 

 howevei" is not very frequently visible. This ferruginous rock, from 

 the slight inclination of the strata, and the denudation to wliich the 

 district has been subjected, forms the cliff for some distance; it is 

 about 30 ft. thick, and consists in its upper part of rather incoherent 

 sandstone, with small pebbles and bands, or veins of ironstone : the 

 lower part is more dark-coloured and coarser grained, the pebbles 

 being of larger size, and united by ferruginous matter. Throughout 

 this bed are many grains, of variable size, of hydrated peroxide of 

 iron, occasionally pisolitic, with titaniferous iron ore, sometimes 

 magnetic, and to which, as well as their decomposition, the colour of 

 the rock is due. This part is traversed by fissures, and divided into 

 oblong blocks, with a hard ferruginous outer coating, and with a 

 grey or green interior. This hardened bed forms the floor of the 

 shore for some distance, and partially protects it. It also forms pil- 

 lars in the cliff (owing to the eroding action of the sea), which support 

 the upper beds. No fossils have been found in the upper portion of this 

 sandstone, but a line of nodules near the base have yielded Ammonites 

 Deshayesi, Am. Cornuelianus, Perna Mulleti, and other species charac- 

 teristic of the base of the Lower Green sand, and which are con- 

 sidered by Mr. Wiltshire to be in place, and by Mr. Judd to be 

 derived from the disintegration of Lower Neocomian strata, like the 

 deposits with phosphatic nodules at Potton and Upware. 



The indurated ironstone is known as Carstone in Norfolk, and is 

 largely used for building, as may be seen in the new houses at Hun- 

 stanton, and the farm and other buildings elsewhere. The late Mr. 

 S. Woodward mentions that it was also used for "querns," or corn- 

 mills (Geology Norfolk, 1833, p. 30). The iron grains are abundant, 

 but not used here economically, although workable iron ore is obtained 

 from the same formation near Tealby and Caistor, in Lincolnshire, 

 and at Seend, in Wiltshire. Remains, however, of the products of 

 old furnaces where iron-smelting had been carried on, have been 

 observed in several localities in the northern part of Norfolk. 



These disintegrated iron grains, from their weight, are separated 

 by the wind from the lighter particles, and form darker patches 

 here and there on the sands of the shore. Overlying these sands, 

 and separated from them by a thin incoherent bed, comes the 

 Eed Chalk, about four feet thick, abounding in rolled and sub- 

 angular pebbles of quartz and other rocks, and containing many 

 fossils, of which the most abundant are Terehratula hiplicata, BcJeni- 

 nites atteiiiiatus, B. minimus, Ammonites auritus, and A. Jnutus, with 

 fifty other species, the upper part being much harder than the lower, 

 and the colour somewhat unequally distributed, but sometimes so 



