MIDLAND COUNTIES GEOLOGICAL SOCIETY. 185 
Fault ; it exhibits the upper measures in well defined beds, 
and is occasionally varied by an outbreak of trap of peculiar 
character. In this open work have been found fossil treeSj 
upwards of twenty feet in length, and shells apparently allied 
to the freshwater mussel in myriads, evidencing the inland 
origin of the strata. A large open work belonging to the 
trustees of the late Earl of Dudley, near the Wren^s Nest, 
will also amply repay a visit. It has been long supposed 
that the Basaltic Rocks were unknown on the western side of 
the Wolverhampton Fault: some of your members, have, 
however, discovered a bed of a remarkably compact nature, 
which protrudes through the nev/ red sandstone, and comes 
to the surface about 300 yards north of Essington Brick 
Yard, and about a quarter of a mile west of the fault. The 
new red sandstone is well developed beneath the excavated 
clay, and leaves no doubt, which otherwise might arise, v/ith 
regard to position. The nearest known point in which the 
Basalt occurs, is in a pit, sunk by the late Mr, Underbill, at 
Pool Hayes, about li mile south of Essington Brick Yard, 
and within the known range of the coal field ; the Basalt at 
Pool Hayes is of great thickness — (Mr. Underhills^s borings 
in it being 54 yards). The character of the rock is not so 
compact as that at Essington, owing to a difference in the 
cooling of the mass, and is remarkable as containing fine 
chrystals of carbonate of lime, Mesotype, and Prehnite. 1 he 
Pool Hayes basalt is undoubtedly connected with the con- 
tinuous beds of Bentley, Willenhall, Wolverhampton, and 
Bilston ; and your Committee v/ould suggest the importance 
of ascertaining the connexion, if any, i^etween the basalt at 
Pool Hayes and Essington ; and also of making dihgent in- 
quiries as to the probable extension of the rock in other 
localities, westwardly of the great fault. 
VOL. II. NO. XYII. 
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