Mr. Rose’s Sketch of the Geology of West Norfolk. 39 
Norfolk, I found that it was nothing more than a tertiary lig- 
nite of the ‘ crag’ period ; which becomes exposed in ihe bed 
of the sea as soon as the waves sweep away the superincum- 
bent strata of bluish clay*.” 
Mr. Bakewell makes the following remarks: “ But these 
subterranean forests in England deserve more attention than 
thev have hitherto received from geologists; the period of 
their growth, and the causes by which they were submerged, 
are at present unknown. A similar subterranean forest ex- 
tends into the sea on the coast of Flanders. Have these forests 
been once united, and afterwards separated by a subsidence, 
which formed the bed of the German Ocean +?” 
Dr. Alderson and Mr. Taylor appear to have considered 
these forests to have been antediluvian: I am not sure that 
I understand Professor Lyell on this subject; his Jignite, I am 
aware, is antediluvian, but in it, does he include “ large stools 
of trees, their stems, and branches” ? If the subterranean and 
submarine forests of the eastern coast be antediluvian, the sub- 
terranean forests of Marshland are not contemporaneous to 
them, but of a more recent period, for they, with the beds of 
peat, are invariably found above what is considered diluvial 
debris. 
On the date of this “once sylvan tract” I ought not to 
venture an opinion, for I have no personal acquaintance with 
it, never having had an opportunity of examining the spot; 
indeed, itis very difficult of access; and until it is determined 
upon what substratum the “ mud inclosing the vegetable mat- 
ter” is deposited, we cannot assign to the submarine forests 
their place in the scale of formations: still, I cannot consider 
this submarine forest (from the data connected with it already 
collected) to be contemporaneous with the lignite of the crag 
exposed in the cliff at Cromer, but believe it to be of the 
same epoch as the subterranean forest of the fens, and that its 
submergence was the result of the subsidence which formed 
the trough for the German Ocean. 
Recent writers evidently consider the subterranean forests 
to be postdiluvian: thus, Phillips writes, “ All the lacustrine 
deposits containing peat, which I have inspected in Holder- 
ness, agree in this general fact, that the peat does not rest im- 
mediately upon the diluvial formation beneath, but is sepa- 
rated from it by at least one layer of sediment, which is seldom 
without shells + .” 
* Principles of Geology, by C. Lyell, Esq., second edition, vol. ii. p. 273. 
+ Bakewell’s Geology, 3rd edit. p. 513. 
t Ulustrations of the Geology of Yorkshire, by J. Phillips, Esq., p. 55. 
[See also Phil. Mag. and Annals, N,S,, vol, ix. p. 353,—Ebir. | 
