220 
THE CRETACEOUS ROCKS OF BRITAIN 
Grey lumpy or knotty chalk with thin shaly partings at 
intervals --------- 
Coarse grey irregularly bedded chalk - 
Beds concealed by talus, about ----- 
Selbornian.—Red Rock exposed at bottom - 
ft. 
8 
4 
6 
1 
The beds hidden in the quarry are exposed in a neighbouring 
ravine, and consist of the following : — 
ft, 
3 
1 
1 
3 
Inoceramus Bed.—Grey chalk with Inoceramus shells 
Sponge /Pale yellow nodular chalk with pale red spots 
Bed. | Red and yellow mottled nodular chalk - 
Selbornian.—Deep red nodular chalk - 
Zone of OfFaster sphaericus. 
The following are some of the most important exposures in this 
zone, beginning near Welton. 
A quarry by the Cross Keys Inn, south of Welton Windmill, 
shows the following section : — 
ft. 
Zone of ! Tliin-bedded rubbly chalk, with layers of buff-coloured 
Off aster 
sphaericus. 
10 
Very hard nodular grey chalk, with Rhynchonella 
mantelliana (Totternhoe Stone) - 3 
Hard greyish-wliite chalk in thin beds, with shaly 
partings --------- 6 
5 
24 
Zone of 
A mm. 
varians. l^Hard greyish-white chalk in beds about a foot thick 
The coloured bands of this zone first set in on the south side of 
the valley of the Calceby Beck, which traverses the Wolds by Calceby 
and South Thoresby. At the latter place there is a quarry in which 
a good section is exposed, as below : — 
Belemnite Marl— variegated marl in two layers, with a band 
of grey lumpy chalk between, lower layer red, buff, and 
green ----------- 
Pale pinkish-white chalk in one massive course 
Hard yellowish-pink chalk in beds about a foot thick - 
Greyish-white chalk in thin beds with shaly partings 
Hard compact greyish chalk in two beds - 
Layer of grey shale 
Hard cream-coloured chalk -. 
Thin layer of soft yellowish marl 
Reddish marly chalk, with a band of chocolate-red marl in the 
middle, brick-red above and pink with grey lumps below 
Layer of grey laminated marl 
Hard greyish gritty chalk, nodular and broken 
TnUpmtnof Greyer and more compact chalk 
Stone 1 grey chalk with nodular crystalline lumps, 
I some of which have yellow stains- 
ft. 
H 
3 
7 
6 
4 
K 
6 
2£ 
1 * 
38 ] 
