VII. Some Observations on a Bed of Trap occurring in the Colliery of Birch Hill, near Walsall, in Staffordshire.
Arthur Aikin · Transactions of the Geological Society of London · 1816
Although 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 a plan of the colliery and with registers of the strata pierced through in sinking the three deepest pits, having also an opportunity of questioning several intelligent miners who had themselves worked in the colliery, and of examining many tons of trap rock and of the adjacent beds which had been brought to the surface, I think that there will be found no material error in the following statement. The surface of the colliery at Birch-hill (Pl. 12. fig. 1.) somewhat exceeds 83 acres;