Revised geological maps of Darlington based on new borehole information: explanation and description

The geology of the Darlington area has been revised based on the interpretation of new borehole information and a re-examination of archival data. The Permian Zechstein Group has been mapped through the district where it forms a series of easterly-dipping formations. These strata have been folded and an easterly-plunging syncline, faulted on its southern side, is mapped through the town of Darlington. This fold structure is partially modified by the dissolution of gypsum in the sequence resulting in the partial collapse and foundering of the strata. A series of maps is presented showing the revised geology, rockhead, drift thickness and the thickness of the gypsum sequence present at two horizons; the Hartlepool Anhydrite (present in the Edlington Formation) and the Billingham Anhydrite (present in the Roxby Formation). A series of five structure contour maps are presented illustrating the fold and fault structure of the area.