Fox Hole Anticline - northern limb with mine adit

Structural geology of Little Haven and The Settlands

The cliffs from Little Haven to Broad Haven (and northward) display a spectacular range of geological structures, folding, faulting and thrusting, mainly in the Lower Coal Measures. The relatively weak mudstone and shale-dominated sequences show much incompetent deformation: tight, thrusted and overturned folds, in contrast to the thicker, stronger, sandstones which have formed relatively open and concentric folds.

The northern limb of the Fox Hole anticline forms the southern headland of The Settlands bay. The style of folding is open and concentric, largely due to the thick (approx 70 m in total) and competent (strong) nature of the sandstone of which it is comprised. At the western end of the headland the bedding dips at about 30° to the north, but this steepens along its length to become near-vertical at the eastern end of the headland.

This is a view from The Settlands looking head-on at the steeply dipping bedding surfaces. The bedding is cut by nurmerous joints (fractures). Just left of centre is a fenced-off mine entrance a few metres above beach level. This is thought to be a former drainage level to dewater coal mine workings, possibly in the core of the anticline and perhaps further inland.