Swallowtree Bay anticline-syncline couplet: detail 1

Saundersfoot to Swallowtree Bay geological structures

Detail view no.1 of the asymmetric anticline-syncline couplet in Lower Coal Measures sandstones and siltstones, just south of Swallowtree Bay.

A curved, northerly dipping thrust just above the top of the walking stick disrupts the anticline fold axis. The thrust becomes near horizontal when followed up to the left of the centre, with crumpling and repetition of the bedding just above the thrust plane.

The stronger sandstone beds show a strong fracture fan cleavage perpendicular to the bedding, especially marked on the vertical limb of the fold.

Scale: the walking stick is 0.9 m long

The photo of the entire structure is here: