OF THE TJPPEE CEETACEOTJS IN WEST SD"FEOLK AND N0BF0LK. 569 



The section is : — 



Upper Pit. feet. 



Soil and rabble 1 



Thin-bedded, rather tough chalk, dull white 20 



Lower Pit. 



Rubble 1 



Firm-bedded white chalk 12 



Hard chalk, rather rough, parting along greenish 



marly lines, massively bedded 2^- 



Massively bedded, greyish, marly chalk 12 



Beyond Gayton a slight ridge, more or less marked by spreads of 

 gravel and nowhere a pronounced feature, continues ; and near its 

 summit, at Grimston, about half a mile south-east of the church, an 

 old pit showed very hard and rough yellowish chalk at the top, with 

 rather hard, but smooth, white chalk beneath it. Microscopical 

 examination proves the hard yellow chalk to be the Melbourn Rock. 



An excellent exposure of the upper part of the Grey Chalk occurs 

 at Hillington, in a large pit in which the chalk is quarried for lime- 

 burning. As usual, the pit is in two sections, which are as follows : — 



Upper Pit. feet. 



Soil and rubble-chalk 1 



Thin-bedded, platy chalk, hard, and much stained 

 with yellowish ; a thin band of buff-coloured marl 

 near the top 19 



Lower Pit. 



Whitish, thin-bedded chalk 4f 



Thin, but persistently yellowish-buff marly band. 



Hard, massively bedded, whitish chalk 4 



Bedded chalk, dull white, with greyer-coloured beds 

 or bands 10 



The chalk in the lower part of this pit divides into rather massive 

 blocks along joints or veins of greenish-grey material, not unlike 

 that seen in the partings of the Melbourn Rock. Overlying this, 

 and a marked feature in the pit-face from its massive appearance 

 and thick bedding, is a layer of whitish chalk, which breaks with a 

 clean fracture, and is in appearance and structure like the firm 

 white chalk which we have noted as underlying the Melbourn Rock 

 at varying distances in Hertfordshire, Cambridgeshire, &c. The top 

 of this exposure cannot be far below the Melbourn Rock. The 

 higher thin band of buff- coloured marl may be the attenuated repre- 

 sentative of the Belemnite-marls of Hertford and Cambridge. 



In the railway-cutting just north of Hillington Station, hard, 

 yellowish chalk, with rough fracture and full of fragments of Inoce- 

 ramus-sheYLs, was seen. This is probably just above the Rock ; 

 proceeding up the cutting, the chalk gradually became whiter, less 

 shelly, and not so hard. 



It may be noted here that, for a considerable thickness, the base 

 of the Middle Chalk of Norfolk is extremely hard, a peculiarity 

 which probably extends through the zone of Eliynchonella Ouvieri, 

 as at Dover. 



The outcrop of the Melbourn Rock probably follows the contour 



