488 
THE CRETACEOUS ROCKS OF BRITAIN. 
oxide of iron after treating a sample of chalk from this quarry 
with acid. 
The next good section is in the cuttings on the Hull and Barnsley 
Railway by the east of South Cave. These also were revisited bv 
Mr. Hill in 1899, and the following observations were made by 
him: — 
“ The lowest parts of the Rhynchonella Cuvieri zone are best seen 
near the western entrance to the short tunnel under Sugar Loaf 
Hill; this part is 13 feet thick, and consists of hard, rough, yellowish 
chalk without flints, divided into courses by thin seams of yellowisli- 
grey marl. The courses are from a foot to eighteen inches thick, 
and the chalk weathers into flattish platy fragments ; it contains 
I noceramus mytiloides, and is succeeded by rough chalk with flints. 
“ The upper part of this zone is well exposed in the cutting between 
the second short tunnel and the long tunnel under Hill. 
Here the rough hard chalk, with layers of flint nodules, which 
appears to belong to the zone of Rhynch. Cuvieri, is continued, 
and its total thickness must be about 50 feet. Above this is from 
20 to 25 feet of chalk with very few flints, and this is succeeded by 
firm white chalk, with well-marked layers of flint nodules about 
10 feet apart. At the base of this last division are two courses of 
hard chalk, which weather out prominently ; these may correspond 
with the chalky limestone seen at the top of the quarry near Hessle 
Station. 
“ This chalk, with layers of flints, is not accessible for measuring, 
but can be touched over the mouth of the tunnel, where I obtained 
several T erebratulina gracilis. Near the top of the cutting are 
two conspicuous layers of marl. No tabular or continuous flint is 
visible. The total thickness seen is from 130 to 150 feet.” 
The succession here appears to differ somewhat from that at 
Hessle, though there is a sufficient likeness between them to make 
it probable that both zones have continued to expand from Hessle 
northwards. Flints here make their appearance in the Rh. Cuvieri 
zone, and this appears to have a thickness of not less than 60 feet, 
while that of the Terebratulina zone, so far as it is exposed, may 
be put at between 70 and 80 feet. 
Whether this part of the Chalk exhibits any further differences 
as it passes northward, or whether it continues to exhibit the facies 
seen in these cuttings we are unable to say, for no one has pub¬ 
lished any sufficient information about the inland exposures of 
these beds. The Rev. J. F. Blake says they can be seen at many 
places along the course of the Wolds, but also expressly states that 
he could not distinguish a zone of Terebratulina gracilis (op. cit., 
p. 262). 
Mr. Hill has recently (1899) found a good section of the Rh. Cuvieri 
zone in a quarry at Good man ham, near Market Weighton, the 
