568 MESSES. JUKES-BEOWNE AKD W. HILL ON THE LOWEE PAET 



A little north of this quarry are two cottages ; and we are 

 informed by the Eev. H. J. Sharpe, Vicar of Marham, that a well 

 was sunk here some years ago to a depth of 85 feet, clay being 

 touched at that depth and bored into for about 30 feet. The water- 

 supply runs short in dry seasons, and is probably therefore derived 

 from the Chalk, the bore not having been carried far enough to 

 reach the Lower Greensand. As the cottages are very little below 

 the level of the Melbourn Rock, we may estimate the thickness of the 

 Grey Chalk, Totternhoe Stone, and Chalk-marl together here as 

 about 90 feet, which is probably from 30 to 40 feet less than their 

 combined thickness at Stoke Perry. 



Another large quarry at Marham, south-east of the church, shows 

 an exact counterpart of the section at the first quarry, and calls for 

 no especial remark. 



From Marham the Melbourn Rock can be followed along the 

 ridge on which its outcrop occurs, the rock itself being shown in 

 one small exposure about two miles to the north of the preceding. 

 Beyond this, though we are able to follow it by the character of 

 the chalk and its contained fossils, the features usually formed by 

 its outcrop may be said to be lost. The thinning-out and gradual 

 hardening of the Lower Chalk in West Norfolk, as well as the 

 severe glaciation to which this county must have been exposed, may 

 account for this. The outcrop of the Grey Chalk is much hidden 

 beneath Boulder-clay or spreads of gravel, but several good sections 

 occur. 



About a mile south-east of Narborough Station, hard rubbly chalk 

 is seen in an excavation, made probably to obtain material for the 

 railway. The exposure is much overgrown ; but the character of 

 the cbalk indicated a close approach to the Hock. 



In a pit half a mile south-east of Narborongh church, hard 

 whitish chalk, similar to that lying immediately below the Bock, 

 was exposed. 



Beyond the valley of the Nar are several pits in the chalk, but 

 all above the Melbourn Rock • a little below them a slight ridge 

 may possibly indicate its outcrop. We are able to identify it again 

 in an old pit close by the church at Gaytonthorpe, hard, yellowish, 

 nodular chalk, with a rough fracture, being exposed. A large 

 Ammonite, closely resembling in form and state of preservation 

 specimens from the Melbourn Rock of Hertfordshire and Cam- 

 bridgeshire, was found here. 



A good exposure of the lower part of the Grey Chalk occurs at 

 Gayton. As is frequently the case in Norfolk, this pit is worked in 

 two parts, an upper and lower, which, though separated by a consider- 

 able interval, yet form a continuous section. The chalk seen here is 

 not of the same character throughout ; it is rather darker grey at the 

 base, and overlying this is a harder, more massively bedded layer, 

 not unlike that lying beneath the Red Chalk at West Row. Above 

 this the chalk is whiter, thinly bedded, weathering in thin platy or 

 flaggy pieces. 



