VALLEY CF THE RIVER STORT 335
provided an adequate supply of flints which could be used for the manu-
facture of artefacts. A full solution to the problem will involve the careful
examination of all glacial and river deposits in southern Essex in order
to trace the movement of these flints. So far as their later history is con-
cerned, the writer has already discovered examples in the Flood Plain
Gravels of the Stort and Lea at Bishops Stortford and Nazeing respectively.
Mr. S. H. Warren has found Clactonian artefacts in this characteristic
material at Elsenham, Essex. Unfortunately, owing to the small amount
of Chalk which is quarried in this part of Essex, very little can be known
of the total distribution in situ of this facies of flint.
At present the writer has no evidence which shows how the raw material
just described received its characteristic coloration as seen in the Swans-
combe and Clacton deposits.
3. ACKNOWLEDGMENTS
The writer is indebted to Messrs. J. D. and D. M. Watson, M.M.I.C.E.,
for permission to visit borehole sites, to examine records and samples, and
to publish the first part of this report. Messrs. D. Heath & Sons kindly
gave permission to visit their pit and to publish the second part of the
paper. Mr. P. C. Lodge was responsible for photographic work, and various
geologists, notably Mr. S. H. Warren, have discussed aspects of the work
with the author.