Westbury

Late Triassic (Rhaetian)

Lithology
Dark grey mudstones or shales with subordinate thin limestones, sandstones and fossiferous arenaceous units ('bone beds').

Upper Boundary
Placed at locally transitional junction with overlying Cotham Member of the Lilstock Formation.

Lower Boundary
Usually non-sequential with underlying Blue Anchor Formation, locally transitional.

Representative Sites
Garden Cliff

Information on lithology and boundaries taken from the British Geological Survey Lexicon of Named Rock Units