The dataset results from a multi-disciplinary geological and geotechnical survey, carried out on contract for the Department of the Environment, to aid planning in an area of south Essex. This area had been designated for urban and transport developments to accompany the construction of a proposed third London Airport on Maplin Sands. The major part of the dataset comprises borehole logs and the results of in-situ and laboratory geotechnical tests, together with interpretative maps and sections. There is also data from palaeontological and mineralogical studies and geophysical surveys. The data is not currently available in digital format.