Superficial deposit thickness model

Superficial Thickness Model sample — Superficial thickness model sample. BGS © UKRI.

1:50 000
Great Britain
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The Superficial Deposit Thickness Model (SDTM) shows the modelled variation in thickness of unconsolidated deposits, less than 2.6 million years old. This includes everything that is fluvial, glacial, marine, residual, aeolian or anthropogenic in origin. The thickness of these deposits represents the depth down to top of bedrock, known as ‘geological’ rockhead. The SDTM comprises three individual datasets of information, two sets describe thickness variation as modelled via two standard geo-mathematical techniques, and a third set details ‘proximity’ or ‘fit’ of the data to the original source information (useful for determining confidence or uncertainty in the models).

Supporting documents

Sample data Access the data

Key information

Scale:: 1:50 000
Coverage:: Great Britain
Availability:: Premium
Price:: £0.18 per km². Subject to number of users, licence fee and data preparation fee.

Format:: GIS grid data. (ESRI, MapInfo, others available by request)
Uses:: Local- to regional-level use
Themes:: Geology, Geoscience information

Superficial deposits are the youngest geological formations (less than 2.6 million years old). They are largely unconsolidated and cover much of the bedrock of Britain. They generally include sediments deposited during the Pleistocene (Quaternary) glacial episodes and subsequent Holocene rivers and coastal systems; superficial deposits also include modern, artificial deposits such as mining spoil and road embankments.

The superficial thickness model was created using digital mathematical interpolation techniques, analysing information from approximately 600 000 borehole logs held in out archives; it also uses the extent of superficial deposits from the 1:50 000-scale digital geological map of Britain: BGS Geology 50K.