1866.] WOOD RED CRAG. 547 



follows tlie coast to Weybourne, and, running thence parallel to the coast, 

 terminates near Wells. 



a, Chalk, b, London Clay, c, Coralline Crag, d, Eed and Fluviomarine 

 Crag, divided as follows : — d}, Walton Crag ; d^, Sutton oblique or Beach Crag ; 

 d'^, Butley oblique or Beach Crag ; d-^+, Horizontal Crag, with phosphatic nodule- 

 band at the base ; #, Scrobicularia-crag, slightly oblique at the base, but hori- 

 zontal in the upper part; d^+, Alternations of sand and comminuted shell 

 overlying phosphatic nodule-Crag (equivalent of d^) ; d"^', Fluviomarine Crag ; 

 d;^' and d^', Unfossiliferous sand (equivalents of d^ and d^) ; these sands are 

 20 feet and more in thickness around South wold and Aldborough, but attenuate 

 near the edge of the Crag in Norfolk, thinning there from 11 to 4 feet in 

 different sections, e, Chillesford shell-bed ( J:^a-bed of Fisher ; and at Bra- 

 merton, Postwick, and Thorpe near Norwich, this is the Upper Crag of 

 J. Taylor) ; this bed is not constant, although the sand containing it is so : the 

 prevalent shells of this bed are Tellina obliqua, T. jprcBtenuis, T. lata, Cardium 

 edule, Purpura crispata, Litorina litorea, Cyprina Islandica, Mactra ovalis, and, 

 at Chillesford, Mya truncata : the Tellina prevail over all others ; mammalian 

 remains occur in it at Chillesford, Easton Chff, and Saxlingham ; e'. The Chil- 

 lesford Clay; laminated clay interbedded with sands at the top; the base of 

 this clay contains in places the shells of e. /, The Bure-valley beds : these are 

 fossiliferous only in places, and only where they rest on the chalk, the shells 

 occurring in small patches ; they consist of sands with shingle-beds : the pre- 

 valent shells are Tellina obliqua (very common), Cyprina Islandica, and Car- 

 dium edule ( T. pratenuis and T. lata cease to prevail) : these beds are often 

 considerably indented into ef. g. The Lower Drift, or Lower Glacial, divided 

 as follows : — g^, The Weybourne sand ; this thins out between Mundesley and 

 Bacton. East of Cromer it is generally stained with the debris of beds dd, and 

 becomes in places, particularly towards Mundesley, laminated with clay bands, 

 in which condition it forms the laminated beds of the Kev. J. Grunn. Between 

 Cromer and Weybourne it (or at least the base of it) forms the Norwich Crag 

 of Samuel Woodward, of Sir Charles Lyell, and of the Eev. J. Gunn. The 

 prevalent shells are Tellina obliqua, Cyprina Islandica, Purpura crispata, 

 Cardivm edule, and Tellina Balthica (solidula), which latter shell here makes 

 its appearance in profusion. The occurrence of this shell at any lower horizon 

 is doubtful ; and if it does occur, it must be excessively rare. It is given by 

 S. P. Woodward from Postwick "top bed;" and a specimen is in the Norwich 

 Museum, marked from Coltishall; but these are doubtful localities. Tellina 

 lata and T. pratenuis have either disappeared at the horizon of g^, or become 

 too rare to be readily detected. It also yields mammalian remains, g'^. The 

 Cromer Boulder-Till (Boulder-clay of Sir Charles Lyell and Lower Boulder- 

 clay of the Eev. J. Gunn). This at one extremity passes into a white marl, 

 formed of redeposited chalk finely ground up. g^, The Contorted Drift. This 

 bed ceases to be contorted east of Mundesley, and becomes regularly and closely 

 stratified. Between the termination of the coast-section (at Hasborough) and 

 North Walsham, it passes into a tenacious green Brick-clay; approaching the 

 coast, near Yarmouth, it changes to a reddish sandy brick-earth, and further 

 south into red sand. West of Weybourne it changes into chalky loam and 

 sand with chalk-grains, g^. Intermediate beds of gravel occupying deeply-cut 

 troughs through g'^ and g^ and underlying^, h, Middle Drift or Middle 

 Glacial: sand and gravel. This bed is chiefly fine, light, yellow, siliceous 

 sand ; but towards London, and where present in the more central counties, is 

 extensively interbedded with gravels, and sometimes with thin beds of sandy 

 brick-earth, i. The Upper Drift or Upper Glacial, being the widespread true 

 Boulder-clay, of great thickness before denudation, dd. The Forest- bed and 

 gravel, containing fluviatile shells and mammalian remains, being probably 

 the land equivalent of the beds from d^ to /. This has been destroyed in part 

 by the waters of g^. N.B. The so-called Forest-bed at Easton Bavent is a 

 post-glacial and very recent peat, occupying the valley-bottoms and occurring 

 on the beach only in the places where the valleys open to the sea. The dotted 

 lines show the continuation of deposits, where their distinctive characters are 

 obscure, or where they are represented only by an undistinguishable mass of 

 sand, except in the case of the Fluviomarine Crag (d^'), which may not be 

 continuous, but possibly the deposit of more than one estuary. 



