Swallowtree Bay anticline-syncline couplet: detail 8

Saundersfoot to Swallowtree Bay geological structures

Detail view no.8 of the asymmetric anticline-syncline couplet in Lower Coal Measures sandstones and siltstones, just south of Swallowtree Bay. This is virtually the same as detailed view no.6 but with the walking stick added for scale (0.9 m long)

This photo shows the vertical limb of the fold couplet pair. In the centre, the vertical limb is composed mainly of sandstones with thin darker silty laminae. The sandstone beds show a strong fracture fan cleavage perpendicular to the bedding, especially marked on this vertical limb of the fold. Minor thrust planes disrupt the thinner sandstone beds by a few centimetres. To the left, finer, darker, laminated siltstones show little or no cleavage.

The photo of the entire structure is here: