VII. Some Observations on a Bed of Trap occurring in the Collier f of 

 Birch Hill, near Walsall, in Staffordshire. 



By Arthur Aikin, Esq. Secretary to the Geological Society. 

 Read November 20th, 1812. 



.LTHOUGH 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 frac- 

 tures 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 j but being furnished with 



2i2 



