LOWER CHALK—SURREY. 
53 
Phlnritin Mnrl /Buff-grey marly chalk, passing rapidly to grey ft. in. 
A, \ very glauconitic marl ; no division possible - 3 6 
Grernisand. } Firm grey-green glauconitic marly sand - - 10 0 
The upper part of this zone is exposed at the bottom of the 
large quarries at Brockham, where a bed of hard, compact chalk 
has yielded Am.[Schloenbachia] varians, Am.[Acanth.] rotomagensis, 
and Anisoceras armatus. 
Zone of Holaster Subglobosus. 
The upper beds of the Lower Chalk, and the base of the Middle 
Chalk are seen at the northern entrance of the tunnel, between 
Warlingham and Oxted. Mr. Caleb Evans describes this chalk as 
the “ Upper Marden Park Beds.” The chalk seen in this cutting 
is chiefly the base of the Middle Chalk, but near the tunnel some 
20 feet of the Lower Chalk is exposed. The sides of the cutting are 
not easily accessible, and the following section was taken by Mr. 
Hill a little distance north of the entrance to the tunnel: — ft. 
Middle Chalk. —Hard rough nodular chalk—Melbourn Rock 8 
' Yellowish-grey laminated marl, with lenticu¬ 
lar beds of hard white chalk, Actinocamax 
plenus 1 0 
* Hard yellowish-grey marly chalk, weather- / 
ing in thin platy pieces, with marly con- 
choidal fracture, Actinocamax plenus 
-Firm whitish chalk, seen for about - 
m 
0 
Subzone of 
Actinocamax 
plenus. 
3 6 
10 0 
Zone of Holaster 
subglobosus. 
The large Oxted quarries just east of the southern end of the 
tunnel show some 50 feet of the upper part of the Lower Chalk; but 
the Belemnite marl was not accessible at the time of our visit. 
In the large quarries north of Merstham Station about 70 feet 
of the Lower Chalk is exposed. The Belemnite marls are seen 
about two-thirds of the distance up the quarry face, and below 
them is whitish chalk some 50 feet thick passing down to greyer 
and more marly chalk. The section is as follows feet. in. 
Soil and rubbly chalk 3 0 
Firm white chalk ( Inoceramus mytiloides ) streaked 
and veined with greenish-grey, weathering along 
the veins into thin platy pieces ( Rhyn . Cuvieri) 18 0 
A massive course of smoother chalk - - 2 0 
Hard rough nodular chalk, streaked and 
veined with green-grey marl - 
A massive course of hard nodular rock 
nodules, creamy white, separated by veins 
of green-grey marl ----- 
, Grey laminated marl, with lenticular layers 
of hard white chalk ; the hard white mate¬ 
rial predominates in the lower part 
I {Actinocamax plenus is common) 
Rather hard greyish-white marly chalk, 
weathering in thin laminae, or platy pieces, 
' fracture conchoidal {Act. plenus) - - 3 6 
Whitish chalk, for about - - - - 50 0 
Passing into greyer and more marly chalk, seen for 20 0 
r*4 
""cS 
0 ( 
A ' 
Melbourn 
Rock. 
"3 
jq 
O 
S-i 
<z> 
£ 
o 
/ 
Subzone 
( of Act. 
plenus. 
3 6 
2 0 
1 6 
* 
These sections were examined in very dry weather. 
