LOWER CHALK—SUSSEX. 
65 
take more than brief notes of the principal exposures in the Chalk. 
These notes have been placed at our disposal. Mr. R. M. Brydone 
has kindly communicated a note on the quarries near Duncton, 
and Mr. Hill has visited the quarries near Bury and Amberley 
in making a traverse down the valley of the Arun. From these 
sources the following account has been drawn up, and will serve 
to indicate the exposures that would probably repay attention. a 
Stratigraphical Details. 
There is a quarry near Elstead, on the north-west side of Beacon 
Hill, which exposes the grey marly chalk of the Ammonites varians 
zone, and from this Mr. Rhodes obtained some fossils (see p. 67). 
In road cuttings and old quarries south of Heyshott Mr. Reid saw 
the following succession : — 
Melbourn Rock. 
( Belemnite Marl. 
Coarse-grained clialk. 
Massive grey chalk. 
Chalk Marl. 
Hard sandy glauconitic marl. 
Greensand. 
The “ coarse-grained chalk ” was exposed in the roadway, but 
not in the quarries. He estimates the thickness here at 180 to 
200 feet. 
There are two quarries in the Lower Chalk south of Duncton 
Church. The lower of these is now disused and talused, but Mr. 
Brydone states that a good section of the Chalk Marl was formerly 
exposed here, and that he obtained many fossils from it. Writing 
of them he says :— 
“ The greater number of the fossils came from the lowest band 
in the pit, a bed of dark bluish-grey marl about 4 feet thick, soft 
when wet, but drying to a hard marl, and having a notably con- 
choidal fracture. Brachiopoda , Serpula, and Onchotrochus were 
especially abundant in this marl; other fossils were less common. 
Above this is about 10 feet of lighter grey chalk with few fossils, 
succeeded by a bed of very hard chalk mottled in light and dark 
grey, and containing many Cephalopoda.” 
The floor of the pit from which these fossils came is probably 
about 50 feet above the base of the Chalk. 
A little to the eastward, and about 100 feet higher up the slope, 
is another quarry and limekiln where about 60 feet of chalk are 
shown, belonging to the zone of Holaster subglobosus. The species 
found by Mr. Brydone are given below, but he says that fossils, 
except Ostreidce, were scarce. 
Again, in the lane leading up West Burton Hill, Mr. W. Hill 
saw beds of greyish-white chalk alternating with beds of marly 
chalk ; Am. [Schloenbachia] varians and Am. [ Acanthoceras ] Man - 
telli occurred frequently at a spot considerably more than 100 
feet above the base of the Chalk. Ascending the lane these beds 
4219, E 
