Melbourn 

 Rock. 



TEE MELJiUUKN KOCK, ETC. 223 



ft. 

 Soil and rubble chalk 4 



I Hard nodular whitish cbalk 8 



I Grey marly chalk 2^ to 3 



Zone of J Hard greyish chalk with whiter nodules (Mar- 



Bel. plena. I bled Rock) 1 



^^ Greenish-grey marly chalk 1 



White chalk '6 



A nodulc-bed agaiu occurs here in the place of the hard white 

 chalk in the zone of Belemnitella i^leaa. In it fossils are abundant, 

 Terehratula semiglobosa, Terehratida hiplicata, WiyncJionella plicatilis, 

 Ostrea vesicularis, and Belemnitella plena being so thickly packed 

 together as frequently to touch each other, but scarcely any perfect. 



In the cutting of the Great i^orthern Hail way just south of Hitchiu 

 Station a good section is seen of the chalk immediately overlying 

 the Melbourn Hock. Only the upper portion of the Rock is now 

 exposed. 



ft. 



Soil and chalk rubble 5 



/ Whitish rather hard chalk full of fragments of 



„ ,. I Inoceramics {Inoceramus mytiloides'i) 20 



Tih C ■ r ■ "^ Hard whitish chalk, nodular, matrix parting 

 I the nodules veined or streaked w^ith greenish 



I gi-ey 20 



Rock [ Very hard yellowish I'ock 4 to 6 



The workmen who dig the chalk for lime-burning at the works 

 close to the station have frequently passed through the whole series 

 of beds which form the rock, and the underlying zone of Belemnitella 

 plena. The yellow aiid upper portion of the Melbourn Rock is 

 known to the men by the name of " smooth hard " chalk, while the 

 whiter and more nodular chalk at the ba?e is known as " curly hard." 



Although the Melbourn liock is seen at many places along its 

 outcrop, there is no exposure in which both it and the zone of Be- 

 lemnitella plena can be seen for nine miles. 



Two miles N. of Luton, on the Leagrave Road, are some lime-works 

 where the following section occurs : — 



ft. 



Soil i 



Rubbly thin-bedded chalk 3 



Rock I -^^^'^ nodular creamy-white chalk 7 



I Buif-coloured shaly marl 1 



I Hard white chalk much broken into angular 



Zone of \ lumps 11 



Bel. plena. \ A thin layer of greyish shaly marl _1 



\^ Dark grey marly chalk 2i 



White toughish chalk dug to 15" 



Two and a half miles N.E of Tring, and near Pitstone, the 

 following section is to be seen : — 



