MIDDLE CHALK—SURREY. 
385 
on p. 54. Here the first 5 feet above the Belemnite Marls is hard 
nodular chalk, weathering along marly veins into a loose rough 
rubble, and above this are layers of hard nodular rock of yellowish- 
grey colour, separated by courses of smoother but hard chalk. 
The succeeding beds to the north are firm and somewhat rough 
but pass up into smoother white chalk. Inoceramus mytiloides 
and Rhynchonella. Cuvieri are common fossils. 
The large quarry at the Oxted Lime Works also exposes the 
Melbourn Rock and some 30 feet of the Rhynchonella Cuvieri zone. 
After passing through a long tunnel, the railway from Oxted 
to Croydon is carried through a series of cuttings, and the first 
seven of these are cut through the zones of Rhynchonella Cuvieri 
and T erebratulina The sections along this line of rail were 
described by Mr. Caleb Evans soon after they were made, and 
the following are extracts from his account.* 
The deepest part of the first cutting is at the northern end of the 
tunnel, where he states it to be 34 feet. From the section at the 
end of the paper, the beds there exposed seem to have been as 
follow: — 
ft. in. 
Rubbly chalk ------ 15 0 
Band of yellowish marl. 
Chalk with marly parting at base - 2 0 
Chalk with Inoceramus mytiloides - 4 0 
Chalk.- 60 
Marly parting with brown earth, Inoceramus. 
Chalk. 7 110 
Parting of brown marl with Inoceramus (shell). 
Chalk with marly parting in the middle - 5 5 
34 3 
He describes the 4-foot bed as crowded with fragments of Incce- 
ramus shells, together with some that are entire. “ On the banks 
the casts of large Ammonites are occasionally met with . . . 
these approach nearest to Am. peramplus of Mantell.” From this 
cutting, which he numbered XIII., he obtained some other fossils 
but none from the next (No. XII.). 
The succeeding cuttings (Nos. XI., X., IX., VIII., and VII.) 
traverse white chalk with a few flints and occasional layers of 
marl; these were called the Whiteleaf Beds by Mr. Evans, and 
correspond with our Terebratulina zone. In cutting No. IX. he 
mentions “ a bed of a nodular and concretionary character with 
ochreous marking, apparently the remains of sponges. Galerites 
subrotundus and Inoceramus Brongniarti are the prevalent fossils.” 
Returning to the escarpment, the Melbourn Rock and some 
20 feet or 30 feet of the chalk above it is exposed in the quarry 
near Caterham Station, and again in that by Merstham Station. 
At Farrington’s Lime Workd, near Reigate, the Melbourn Rock is 
seen nearly two-thirds up the face of the quarry, with about 40 
* Geol. Assoc., Separate Paper (1870). 
