266 SUBMERGED FOREST AT RHYL. 
The succession of beds that fill up the Vale of Clwyd in the 
neighbourhood of Rhyl, are as follows :— 
No.1. Blown Sand... .- .. .. Post-Glacial 
» 2 Alluvium SAT eee oth ees ‘s 
Peat and Forest-Bed .. .. 58 
Blue Clay, Scrobicularia ; = 
Boulder Clay lattes . was Glagial 
Sand and Gravel... .. .. a5 
Nos. 1, 2, 3, 4 are post-Glacial, and 5, 6 Glacial deposits. 
The beds of Sand and Gravel (No. 6), are the principal channels 
by which the underground water escapes. It will at once be 
observed that, in descending order, they underlie the Boulder 
Clay (No. 5), and the Blue Clay (No. 4), upon which rests the 
submerged Peat and Forest-beds (No. 3.) Any subterranean 
erosion of the Sand and Gravel (No. 6), must result in the 
subsidence of all deposits resting upon them, so long as such 
underground waste may have continued. 
Unfortunately, the exposure of the Submerged Forest at Rhyl 
was of so few days that no opportunity of a thorough and 
exhaustive examination of the position and the causes of its 
occurrence was possible 
Mr. J. D. SmppaLt, of Chester, was kind enough to examine 
the Peat (No. 3), and found it to be composed of the Common 
Reed (Arundo phragmites), “ which is very characteristic of wet 
places.” The remains of the Reed were in a very perfect state 
of preservation. The Blue Clay beneath the Peat and Forest- 
bed contained the common Esturine Marsh Shellfish, Serobzeularia 
piperata, erect in the clay, with both valves united as in life. 
The peat was not continuous over the whole exposure, and 
patches of the Boulder Clay or Blue Clay came here and there 
to the surface. From this we may be sure that the forestal 
remains have previously been much exposed to the ravages of 
the encroaching sea, and that agrees with the account in the 
Liverpoot Echo, which mentions that these forestal remains had 
not been seen ‘“ for the period of eighty years.” 
The summary of the evidence would appear to indicate that 
the Blue Clay is the site of an old marsh; that a forest for a 
time succeeded to the marsh, until an interruption in the 
drainage under-ground being removed, subterranean erosion 
again caused the then surface to sink and become a swampy 
wet place, and the fitting habitat of Arundo phragmites. The 
trees had apparently broken off about two feet above the roots, 
which was most probably the water level of the swamp. They 
were believed to be of oak, elm, birch, alder, and hazel. One 
trunk of a tree lay prostrate as though uprooted by a storm; 
the roots faced towards the N.W., the present direction from 
whence devastating storms most frequently occur along this 
coast. The peat in some parts was from eight to ten inches 
Dur pv 
