Geophysical Investigations of the Whin Sill in the Roman Wall District of Northumberland

Abstract

SUMMARY Magnetic and seismic refraction investigations of two areas on the outcrop of the Whin Sill in western Northumberland with obscure geological relationships have served to clarify these relationships. In the area east of Great Chesters, a 0.9 km wide gap in outcrop of the sill is shown to have been produced by a channel eroded 30 m into the sill and filled by glacial drift. In the area of Limestone Corner the transgressive nature of the sill is demonstrated, but the two leaves of the sill are shown not to be connected by a continuous dyke.