176 
SHANKLIN SAND. 
south, and basset out on the north. At Petworth, 
and on the top of the high hill to the eastward, this 
hard stone is dug in great quantities for repairing 
the roads*, and I know not in any country a better 
material. It is usually disposed in irregular beds 
in the sandstone, but occasionally forms veins, 
which intersect the strata j I call the beds irregular, 
because they vary much in breadth and appear not 
to continue far. 
“ The Whinstonet shows a transition into the 
sandstone, and they are certainly of contemporane- 
ous formation. In some situations near Petworth, 
great lenticular masses of this substance are imbed- 
ded in the friable sandstone, and these follow the 
same sedimentary line as the beds of sandstone, 
although separated from each other by very wide 
intervals : they are therefore unquestionably in situ. 
These masses frequently measure eight or ten feet 
by two or three, and are invariably surrounded by 
a more friable and ochraceous sandstone than the 
rest of the strata.” 
The whinstone is sometimes traversed by veins 
of chalcedony, and it also contains cavities lined 
with mammillated concretions of the same sub- 
stance. 
At Parham, near the village of Storrington, and 
in the adjoining parish of Rackham, the sand is 
highly ferruginous, and contains irregular concre- 
* It was also noticed on Bexley Heath, and on the sides of Black- 
down Hill, by Mr. Lycll. 
f Whinstone, the name by which the chert is distinguished in Western 
Sussex, is probably of Saxon origin ; it is unknown in the south-eastern 
part of the county. 
