Superficial Deposits Thickness Models, SDTM

A series of tiled models of superficial thickness covering the UK. The models are derived by direct modelling (natural neighbour interpolation) of BGS Borehole records and BGS Digmap. For the purposes of modelling, superficial deposits include sediments deposited during the Quaternary, subsequent Holocene rivers and coastal systems and also modern anthropogenic material. i.e. deposits that are less than 2.6 million years old. Grids are overprinted with a minimum value so that areas where no bore data is present, but drift is known to occur are given a minimum 1.5m thickness. The superficial thickness models have been created as baseline datasets for the BGS Geohazard programme. They represent the first attempt by BGS to create nationwide models of such data and the models provide only a simple, mathematical interpretation of reality. The complexity of Superficial deposits in Great Britain is such that it is only possible to model indicative values of thickness and elevation. The models should never be used as a substitute for thorough site investigation.