THE ESSEX FIELD CLUB. 
I 1 
ilic taper ends of the roots still remain. In either case the main lignite 
or peat deposit rests on this eroded surface and the lignite and also the 
upper two feet of the old roots are penetrated by small reeds. 
Over most of the area the erosion has been much greater, the sand 
having been swept away almost to the top of the coarse ballast. Over 
part of the base of this hollow, near the east end of the main Dock, a 
curious gravel deposit was swept, composed of rounded flints (mainly 
Reading Bed pebbles)and sand mixed with fine detrital black-wood material 
and freshwater shells, largely comminuted. Evenly dispersed through 
it are thousands of more or less burned flints, which from their flatfish 
upper surface and general aspect appear to have resulted from a forest 
fire ; they are quite unlike the burnt flints, associated with cooking pots, 
referred to later. On this gravelly and peaty material more detrital 
wood and waterlogged trunks of trees were deposited, the trees often acting 
as strainers and catching objects which easily floated such as fresh-water 
snails and hazel nuts, which are often abundant. The number of large 
pieces of decayed timber in this deposit is greater than at any other horizon, 
and solid (i.e., not soft and sodden) tree-trunks are rare. In it an oyster 
shell has been found, and at its base, at two spots, flint flakes of undoubted 
human origin ; there is no trace of a land-surface at this horizon, indeed 
it was obviously an eroded hollow full of water. Above it comes slimy 
clay with many waterlogged sodden fragments of tree-trunks and a fair 
number of undecayed trunks. If a sandy seam occurs in this, fresh-water 
shells are abundant. Many small reeds grew in it, and these penetrate 
the sodden trunks which were in the condition of “ touchwood ” when 
the}’ sank. 
This clay gradually filled the hollow up, or nearly up, to the level of 
the old surface, and the main lignite bed passes over both the sand and 
the later mud continuously, and is everywhere crowded with reeds, showing 
that it was entirely submerged. Not a trace of moss has been found in 
this lignite. It is doubtful now if the pure lignite contains any shells ; 
but there are numerous lenticular seams of clay and silty sand within 
the lignite, often accompanied by slight local erosion, and in these scams 
fresh-water shells are abundant, and more than thirty species have been 
obtained therefrom, which have been kindly determined by Mr. B. B. 
Woodward. 
The mud that succeeds above the main lignite contains a large amount 
of twigs, small pieces of wood, and waterlogged decomposed pieces of 
tree-trunks. The whole of the mud and lignite also contains, sporadically, 
numerous trunks of trees, which are still undecomposed, and these often 
have portions of their roots attached, as if they had been either blown 
down, or let down by the undercutting of the banks upon which they 
grew. 
Several cross-sections of silted-up Creeks, cutting into the peat and 
choked with clayey silt, may be seen on the faces of the excavations ; 
the largest of these is the old Ham Creek, which is stated to have been a 
navigable channel up to late Mediaeval times. 
Vivicinite (blue phosphate of iron) occurs in the peat and the alluvial 
clay, associated with the plant-remains. 
Mediaeval pottery, associated with oysters, bones, burnt flints, and 
