Extract

I beg leave to communicate to the Geological Society some particulars of a whin dyke, which traverses a portion of the limestone strata in the northern district of the county of Northumberland, and projects into the sea on its north-eastern coast.

It is seen most distinctly at Beadnel Bay, and may be traced a few miles inland from this spot, where it forms a species of pier into the sea. The surface strata have been washed away, and the dyke itself is left some few feet higher than the rock on each side of it. Upwards of 300 yards are thus seen at low water running in a right line from the sea towards the north-west, 27 feet in width. It rises in a perpendicular position through all the strata, without making the least alteration in the dip or inclination of those that are adjacent: but some short distance from the place where it is laid open to view, the limestone strata are much broken and dislocated. The qualities of the different strata in contact with the dyke differ materially from those of the same strata at some distance from it, particularly the limestone, which when lying in the immediate vicinity of the whin will not burn into lime of any value. This deterioration diminishes in degree as the distance from the dyke increases, and it is about 20 feet before the limestone acquires its perfect properties of burning into good lime. The same thing is observed in both the