222 



MESSES. W. HILL AND A. J. JUKES-BROWNE ON 



Rock. 



Zone of 



the village. There are two faces to the pit here, the chalk being 

 worked so that the sides of the pit represent roughly two sides of 

 a triangle the apex of which points N.K.E. 

 On the easterly side the section seen is : — 



ft. 



Soil and chalk rubble 5 



Mplbon 'n f Thin-bedded rather nodular yellowish chalk 



with thin marly partings 6 



Hard whitish nodular rocky chalk 44 



^Thin-bedded grey marly chalk with laminated 



marly base 2 



Hard greyish chalk with nodules (marbled 



rock) 1 



BeCplma. < Gi-reyish marly chalk 2 



^ passing into 



White hardish chalk 6 



Hard gritty chalk with a few green-coated 

 ^^ nodules 1 



As at Royston, the hard white rock is absent in the zone of Belem- 

 nitella plena, a nodular band being in its place. This nodule-bed 

 thins out towards the apex of the triangle, and on the more northerly 

 face the section is : — 



ft. 



Soil and rubble 5 



Melbourn f Thin -bedded yellowish chalk 6 



Eock. \ Hard rocky chalk 4f 



y n ( Grrey marly chalk, with harder central band 



■n J J \ of whitish chalk ; passing into hardish 



net. plena, y ^^^^^ ^^^^^^ ^^^ ^^^ \iQiov^) 5 



Fossils, including the typicalBelemnites, are abundant in the nodular 

 bed in the zone of BeUmnitella plena. Six feet below the marly 

 band, which passes gradually into white chalk, there is a thin hard 

 gritty bed with green grains and a few green-coated brown nodules. 

 This bed is in man 3^ respects similar to the hard beds which attain 

 a greater development and importance further to the south-westward. 

 A good exposure of the Melbourn Eock and the underlying zone 

 of Belemnitella plena is to be seen at Ashwell, in the more easterly 

 of two pits, in which chalk is dug for lime-burning. The section 

 is : — 



ft. 



Soil and rubble 2 



Rather hard whitish chalk 6 



f Massive bedded creamy white chalk 2>^ 



Melbourn J passing into yellower thin-bedded chalk with 



Rock. I few nodules 2 



Hard creamy white nodular rock 3^ 



Grrey chalk passing up into laminated marl 



Zone of J or shale 2 



Bel. plena. 1 Hard white chalk 1 



[ Marly greenish-grey chalk 1^ 



Rather rough white chalk. 



In a cutting of the Great Northern Eailway at Cadwell, two miles 

 north of Hitchin Station, the following section was seen : — 



r 



