18 
ALLUVIAL DEPOSITS. 
2. Suhterranean Forests. 
The occurrence of large trees beneath the sur- 
face of the earth, with their leaves, roots, and even 
fruits, more or less preserved, attracted the atten- 
tion of philosophers at a very early period. These 
subterranean forests have been noticed in almost 
every part of England, and various conjectures 
offered in explanation of the catastrophes by which 
they have been overwhelmed. In some instances 
they appear to have been torn up by a sudden 
irruption of the sea, and overwhelmed by the sand 
and mud which it dashed over them ; in others 
they seem to have been submerged by a sub- 
sidence of the land. The subject has been ably 
treated by Mr. Parkinson*, to whose work the 
reader is referred for an interesting account of the 
most remarkable examples. 
The trees are chiefly oak, hazel, fir, birch, yew, 
willow, and ash ; in short, almost every kind that 
is indigenous to this island occasionally occurs. 
The trunks, branches, &c. are dyed throughout of 
a deep ebony colour ; the wood is firm and heavy, 
and sometimes sufficiently sound for domestic use ; 
coins, &c. have been found. On the west side of Gljnd Bridge, a 
paved Roman causeway was discovered, lying three feet beneath the 
turf, upon a bed of silt twenty feet thick ; and near it was found a 
large brass coin of Anloninus Pius. In forming a road across the 
levels, from Ranscomb to Beddingham, a coin of Domitian was dis- 
covered immediately beneath the surface of the soil. This formation 
of the levels was therefore antecedent to the Roman advent : and 
we may infer, that since that period it has not received any material 
addition. 
* Organic Remains of a formcrWorld, vol. i. 
