The Beacon Limestone Formation, historically known as the Junction Bed, is a formation of the early Jurassic age (Pliensbachian–Toarcian). It lies above the Dyrham Formation and below the Bridport Sand Formation. It forms part of the Lias Group. It is found within the Wessex Basin and parts of Somerset, in England. It is well known for the Strawberry Bank Lagerstätte, which contains the 3-dimensionally preserved remains of vertebrates, including marine crocodyliformes, ichthyosaurs and fish, as well as insect compression fossils.

The Bridport Sand Formation is a formation of Toarcian age found in the Worcester and Wessex Basins of central and southern England. It forms one of the reservoir units in the Wytch Farm oilfield in Dorset. The sandstone is very-fine grained to fine-grained and contains regular narrow bands that are calcite-cemented and more resistant to weathering, giving it a characteristic banded appearance at outcrop, such as in the cliffs between Bridport and Burton Bradstock in Dorset. It is named for Bridport and has previously been known as the Midford Sand(s), Cotteswold Sands, Yeovil Sands and Upper Lias Sand(s). It forms a locally important aquifer, particularly around Yeovil.