FLUVIO-MARINE DEPOSIT ON THE ESSEX COAST. 197 



Art. IX. — JVotice of a Fluvio-marine Deposit containing Mam- 

 malian Remains, occurring in the Parish of little Clacton, on 

 the Essex coast. By John Brown, Esq., F.G.S. 



Several lacustrine formations have from time to time been 

 recorded in this Magazine, as occurring in this or the adjoin- 

 ing counties, but their general character has been that of 

 purely fresh-water deposits. 



The one I now wish to bring under notice, is on the east- 

 ern coast of Essex, ten miles south of Walton, and has abun- 

 dance of marine shells, mixed with those of fresh- water. 

 The beds of shells, alternate with thick deposits of peaty 

 matter in the cliffs, to the depth of 18 or 20 feet, as shown 

 in the accompanying section, which was taken on the spot ; 

 and at the same time, the shells, fossil wood, seeds of Char a, 

 and Cyprisy were collected, which I now forward you with this 

 paper. The hollow or basin occupied by this deposit, mea- 

 sures about 600 yards in a north and south direction ; and at 

 low water, it can be traced for about 80 yards eastward from 

 the face of the cliffs ; and it doubtless extends much farther 

 under the sea, as the fresh-water shells, and bones of the fos- 

 sil Mammalia, are seen lying in their lacustrine beds, close 

 up to low-water mark; and we may feel assured, that if this 

 coast continues to be visited with the same destructive ele- 

 ments to which it has been exposed for the last forty years, 

 unless these lacustrine beds are continued for a considerable 

 distance under the surface of the land to the westward from 

 the present line of cliffs, there will be nothing to indicate to 

 future geologists, that a fresh-water lake ever existed here ; 

 but that this fluvio-marine deposit, which now presents 

 so many features of interest from the great number and 

 the character of its organic remains, will, like the beds of 

 crag once seen at Harwich, be swept away by the sea, before 

 many centuries have passed over. 



Geological writings are the only evidence which will trans- 

 mit to posterity that the shelly beds of the crag once existed 

 on the cliffs at Harwich ; and this consideration makes it de- 

 sirable that as great an amount of facts as can now be col- 

 lected, should be published in scientific works open to such 

 observations. 



The finding of fossil fresh-water shells in certain places, is 

 not always indicative of a lake having existed in such spots; 

 the shells may have been drifted down a river into an estua- 

 ry, and by that means become mingled with those of the sea. 

 But in the instance under review, I can adduce not only the 

 fresh-water and land shells, as well as nuts, seeds, and whole 



