The Quarterly journal of the Geological Society of London (12736083873)

THE CORALLIAN ROCKS OF ENGLAND.

305

beds in the neighbourhood, we have no doubt that the red soil here

is the representative of the Upper Calcareous Grit ; but the sands

and clays below, being overlain by oolitic rock, which never occurs

in the tipper Calcareous Grit, and to which the red earth is uncon-

formable, and being in the position of similar beds at Highworth

and elsewhere, we take to be a continued representation of the

arenaceous form of the infra-coralline beds, the erosion being an

interesting indication of the wide separation in time of the oolite

shell-beds and the Coral Rag. These conclusions are confirmed by

sections at Marcham.

All the openings hereabouts are in somewhat the same horizon,

and carry on the sequence of the various divisions, till in the neigh-

bourhood of the last-named village the calcareous type of the infra-

coralline beds sets in, and we have Hag supported on beds of broken

oolite and oolitic brash. A very good example of this is seen in a

limepit near " Noah's Ark," a representation of which we give

without further description (fig. 6).

Fig. 6. — -Section at Noah's-Ark Lime/pit, Marcham.

(Total thickness, 10 ft. 6 in.)

1. Coral Bag. 2. Broken Oolite. 3. Oolite and Brash.

4. Shell Limestone. 5. Lower Calcareous Grit.

Elsewhere in the neighbourhood these brashy and oolitic beds

beneath the Rag are thicker ; but we need only give one illustrative

section, that in " Marcham field," whence doubtless, for many

a decade, the fossils have come which have been quoted from this

locality, and which every writer mentions. There are, however,

two quarries ; and it is the most southerly to which the following

description applies : —

Q..T. G. S. No. 130. x

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