VII. Some Observation: on a Bed of Trap occurring in the Colliery of Birch Hill, near Walsall, in Staffordshire.
By Arthur Aikin, Esq. Secretary to the Geological Society.
Altough several instances have come under my personal
notice in Shropshire and the adjacent counties, of the occurrence of
trap rock in connection with the coal-formation, yet in all these
cases the trap either forms the basis on which the coal strata rest, or
is incumbent on them; or, in the form of dykes, fills up the fractures
or faults. Being informed however by Mr. James (one of
the members of our Society) that a bed of trap had been pierced
through in several places in a colliery, at Birch-hill near Walsall in
Staffordshire, which has lately come into his possession, I took an
opportunity of visiting the spot in the course of the last summer,
and beg leave to lay before the Society the result of my examination.
On my arrival I found that the lower part of the works (in
which the bed of trap is situated) was not as yet sufficiently freed
from water to admit of actual inspection; but being furnished with
