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.

This is a close up view of the northern limb of the Fox Hole anticline taken from beach level. 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.

The sandstone displays a number of sedimentary features, including cross-bedding and channel erosion (visible just above and to the right of centre), formed by deposition in a high-energy delta distributary channel setting. Restoring the anticline to its 'unfolded' condition, these sedimentary structures then indicate a general current flow direction from south-west to north-east.

Folding, faulting and thrusting make determination of the exact stratigraphic correlation of the Fox Hole sandstone difficult, but it is reasonably clear that this is the lowest stratigraphic unit in the Little Haven area and is well down in the Lower Coal Measures sequence.