Earthwatcher's photos with the keyword: joints

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 looking head-on at the steeply dipping bedding surfaces. The bedding is cut by nurmerous joints (fractures) which in this case has been enlarged by erosion to form a shallow sea cave at beach level. Someone has lit a candle on a rack inside the cave. Perhaps a memorial to a loved one?

The tide was nearly at its lowest and extensive rock ledges were exposed at the western end of Pinhay Bay, Devon, just west of Lyme Regis. I was fascinated by the pattern of joints in the rock ledges (White Lias (Rhaetic), I think).