550 Mr. Strickland on the Geology of the line 



§ 2, Red Marl. — The red or Keuper marl overlies the new red sandstone on 

 each side of the Lickey ridge. On the north-east it is traversed by the line of rail- 

 way from Groveley Hill to Birmingham, which town stands on the new red sand- 

 stone, but is closely skirted by red marl on the south and east. The same for- 

 mation extends from Birmingham along the London railway as far as Berkswell, 

 forming, in North Warwickshire, a basin of red marl with the small lias outlier of 

 Knowle in the centre*. This great extension of red marl was not known at the 

 time of the construction of Mr. Murchison's map, in which the new red sandstone 

 of Warwickshire is carried too far to the southward. The true boundary of the 

 marl and sandstone ranges from Hewell Grange nearly north by Cofton Racket to 

 Northfield, and thence north-east to the south suburbs of Birmingham. The 

 course of the railway is nearly parallel to this boundary line. 



On the south-west side of the Lickey ridge, the new red sandstone becomes 

 marly and thin-bedded in the upper part, and eventually passes into the incumbent 

 red marl. The latter retains an inclination of 6° to 8° south-west, resulting from 

 the elevation of the Lickey ridge, till we reach the salt-works at Stoke Prior f. 

 The deep excavation made at this place is fully described by Mr. Murchison (Sil. 

 Syst, p. 31), and I will therefore only remark, that, from the dip of the strata ex- 

 posed by the railway, it is evident that the position of the salt rock must be near 

 the bottom of the marl immediately above the sandstone. 



The red marl presents no other feature of importance till we reach the neigh- 

 bourhood of Hadsor, where the railway crosses a promontory of lias projecting 

 from the main body of that formation (PI. XLVIIL fig. 3.). On the north side, the 

 marl is cut off by a fault, but on the south, at Dunhamstead, is an interesting sec- 

 tion of the junction of the two formations. 



The following section is here exposed : — 



a. Lias clay, with contorted beds of lias limestone containing saurian bones. 



b. White micaceous sandstone, two feet. 



c. Lias clay, six feet. 



d. Grey marl, thirty-five feet. 



e. Red marl. 



The whole dipping 5° N.N.E. 



The sandstone 6 has much resemblance to the " Keuper sandstone" described 



in Geol. Trans, vol. v. p. 332, but it occurs considerably higher in the series. It 



here contains numerous specimens of a smooth oval bivalve, larger and more oblong 



than the Posidonomy a minuta of the Keuper (Geol. Trans, vol. v. PI. XXVIIL fig. 4.), 



* See Geol. Trans. 2nd Series, vol. v. p. 336. 



t See sheet No. 20 of the Railway Section, and Plate XL VIII. fig. 1, upper line. 



