234 
THE CRETACEOUS ROCKS OF BRITAIN. 
Middle Chalk - - ------ 
Soft yellowish marly chalk, enclosing lenticular beds 
Belem- of harder chalk ------- 
nite (Soft grey marl, variegated bluish-grey and buff in 
Marl. upper part, nearly black in middle, and greyish- 
l buff below -------- 
Rough nodular chalk, consisting of harder lumps embedded 
in greenish-grey marl, passing down into hard white chalk. 
ft. 
13 
in. 
0 
1 9 
1 4 
A section almost exactly similar in its details, except that each 
of the marly beds is 18 inches thick, is exposed in a pit about a mile 
and a half south-east of Londesborough by the road leading from 
Towthorpe Corner to Easthorpe (for this see p. 232). There are 
probably other exposures of it in some of the Wold valleys, but 
none have come to our knowledge. 
Mr. Fox-Strangways was informed by Mr. J. R. Mortimer, of 
Driffield, that this marly band was formerly seen in the section near 
Wharram Railway Station.* 
In the Speeton cliff section the Belemnite marls consist of the 
following beds, which form a conspicuous band along the cliff face 
between the hard beds of the Lower and Middle Chalk : — 
ft. in. 
Bedded chalk without flints - - - - - - 76 
( Variegated shaly marl, bluish-grey and buff - 4-6 
Hard smooth white chalk - - - - - -10 
Shaly argillaceous marl, grey above and below, 
almost black in the middle - - - - - 0 9 
In the above account, the several parts of the Speeton section 
have been described under the zonal headings, but a summary of 
the complete succession of the beds forming the Lower Chalk 
in the Speeton cliffs may now be given :— 
ft. 
Zone of 
Of. 
sphoeri- 
cus 
Zone of 
Am. 
varians 
Belemnite Beds (as above) ----- 
Compact whitish chalk in regular courses, the top 
course rubbly, the rest smooth and even - 
/ Massive bed of grey and white streaky chalk 
Rough nodular chalk, divided into courses by seams 
i of greyish marl ------- 
Totternhoe Stone or “Grey Bed” - 
/ Rougli grey chalk in beds about 2 feet thick, with 
marly partings ------- 
( Nodular and marly chalk (partly pink) 
Nodular marly chalk, grey and red - 
^Bluish-grey nodular chalk, with marly seams - 
9 
19 
*> 
o 
20 
2 
39 
10 
18 
10 
A 
123 
Fossils from the Lower Chalk of Yorkshire. 
The following list is taken from those given by Dr. Barrois and 
Mr. W. Hill in the publications already referred to, with a few 
additions and corrections : —c=South Cave cutting. s = Speeton. 
o=other places. 
* Geology of the Country around Driffield, Mem. Geol. Survey, 1886, 
p. 9, 
