The Chalk and its Dislocations. 271 
a few inches, and is bound together by oxide of iron into its normal 
condition of a very hard tenacious conglomerate. It seems to me that 
in its continuity and in its contents and structure it differs entirely 
from the insular and detached areas covered with unweathered flints 
on the foreshore with which Mr. Clement Reid compares it, and any 
theory based on an analogy between them must fail. 
Secondly, I cannot agree with Mr. Reid that this bed “ does not 
necessarily belong to any one horizon.” In the stretch of coast I am 
describing it is an absolutely unique feature, which catches the eye at 
once, from the contrast between its dark ochreous colour compared 
with the white chalk below it and the grey clay or loam or sand 
above it, and from its running continuously along the coast separating 
the clays and sands above from the chalk below and forming a most 
unmistakable horizon. Indeed, I do not well see how such a bed 
could be formed at any other horizon. Its great peculiarities are the 
shells it contains in many places and the iron oxide which has 
coloured it so deeply and has indurated it into a mass of ‘hard pan.’ 
This iron oxide, it seems to me, has been added to the bed, since it lay 
under the sea when its shell contents were accumulated, for it could 
hardly have accumulated in it when it was submerged and washed 
continually by the sea. Its accumulation in this bed is merely due to 
the fact that the rain-water has percolated through the Crag and drift 
sands above it, whose redness and yellowness are caused by the iron 
oxide they contain, and that the flow of this chalybeate water has 
been stopped by the chalk which has filtered it and compelled it to 
throw down the iron oxide in the covering layer of rounded and 
broken flints, and has thus accumulated a very respectable mine of 
iron-ore in this particular bed. This condition could only happen at 
the top of the chalk, and it seems to me that such a bed where it 
exists as it does here, must mark very clearly the horizon separating 
the chalk from its covering beds of more or less porous sand and loam. 
Thirdly, while I do nct dispute the fact that this bed, before it was 
saturated with iron oxide, lay once at the bottom of the sea, as its 
contained shells clearly show, I cannot quite understand how it can 
have resulted from the mere submarine dissolution of the chalk, 
which must be a very slow process indeed, except when it is being 
pounded by a shingle beach and must be very largely limited to the 
area where these waves act and not reaching the laminarian zone. 
Nor can I quite understand how the rolled and broken flints in it 
are to be thus explained. Such beds as have clearly resulted from 
submarine dissolution and still remain on the foreshore have hardly 
any rolled or broken stones in them, but the great uncouth flints 
and paramoudras are held tight and do not move, and are therefore 
not rolled or broken except in very exceptional cases. 
I believe myself that the rounded flints and occasional quartzites in 
this bed of hard pan (as I will call it) are in their present form much 
older than the shells it contains and were rolled or broken possibly in 
the time of the Red Crag sea or perhaps even earlier, and that the bed 
in question must have a very different origin from the mere submarine 
dissolution of the chalky matrix of the flints. This, however, is 
matter which must not detain us at present. 
