British Geological Survey (BGS) Lexicon
From the website: The British Geological Survey (BGS) Lexicon of Named Rock Units, or BGS Lexicon, provides definitions of the lithostratigraphic, lithodemic and lithomorphogenetic geological units of the UK and its continental shelf. The lexicon focuses mainly on geological units of member, formation and group rank (and equivalent) but it also includes information on some units of lesser rank, notably economically important coal seams and laterally extensive marine bands. It includes superficial and bedrock units, plus synonyms and other names that are not currently recognised by the BGS or regarded as obsolete. The BGS lexicon is an authoritative source for names of and information about lithostratigraphic units in the United Kingdom.
TIP This resource can be used as an authority for lithostratigraphic units in the UK and surrounding continental shelf.
Coverage and gaps
Lithostratigraphy of the UK and surrounding continental shelf