Swallowtree Bay anticline-syncline couplet: detail 5

Saundersfoot to Swallowtree Bay geological structures

Detail view no.5 of the asymmetric anticline-syncline couplet in Lower Coal Measures sandstones and siltstones, just south of Swallowtree Bay.

This is a view of the sandstones and laminated sandy siltstones on the southern limb of the anticline, close to beach level.

The sandstone beds show thickness variation due to channelling and erosive bases into the underlying laminated sandy siltstone beds. The latter show fine-scale rhythmic fining-up laminae, which have slightly irregular slumped bases. All these sedimentary features demonstrate that these beds are the right way up!

The lens cap is 72 mm in diameter.

The photo of the entire structure is here: