and Marlborough Railways. 



177 



Upper-chalk. 



II. The Marlborough Railway. 

 The cutting in the Upper-green-sand at Savernake Station, where 

 the Marlborough Railway commences, has already been noticed. 

 At a quarter of a mile from this spot, the junction of the Upper- 

 green-sand and Chalk-marl is passed over, but no section is visible. 

 At Lye Lane there is a good section through part of the Lower-chalk, 

 here consisting of hard thick-bedded stone, dipping north 8°. Ino- 

 ceramus latus, Pecten quinquecostata Ptden Beaveri, Turrilites 

 tuberculatus, Rhynconella Gibbsii, Ammonites varians, Ammonites 

 Mantelli, and sharks teeth were found here. 



In the deep cutting near Lye Hill, the 

 upper beds of the Lower- chalk, capped by the 

 chalk-rock are well seen. The chalk-rock 

 forms a division between the Lower,andUpper- 

 chalk ; it is very constant in its occurrence, 

 and from its greenish yellow colour it is 

 easily recognised. Here it is 10 feet thick 

 and divided into five beds, fig. 4. The Lower- 

 chalk in about 8 inches passes into a band 

 of hard rubbly stone, coated green, in which 

 are nodules of Iron pyrites, causing rusty 

 stains. There is then a sharp line, and over 

 this a bed of hard chalk 2 feet 6 inches thick, 

 - Ft ^ 4, of the colour of the Lower-chalk, capped 



with a dark marly seam about 4 inches thick, forming another 

 well marked divison. The ordinary Lower-chalk is then resumed, 

 but soon gets yellow, and in 3 feet passes into another band of 

 green coated lumps of hard chalk like the first. At 2 feet above 

 this, another similar but less marked band occurs, and at 1 foot 

 above this latter another like it. Then comes a bed of hard 

 rock 1 foot thick, on which is a well marked band of green coated 

 rubbly stone 3 inches thick. Over this begins the Upper-chalk. In 

 these greenish yellow bands, there is a gradual deepening of colour 

 from below upwards, and then a sudden break, and return to the 

 ordinary colour of the chalk. 



The beds of rock, and the rubbly lumps are much harder than the 

 VOL. ix. — no. xxvi. o 



