Smooth Rock convergence 2

Chevron fold syncline in sandstones of the Bude Formation (upper Carboniferous) at Maer Cliff between Northcott Mouth and Bude, north Cornwall. 'Smooth Rock' is the name given to the steeply dipping slab on the right - a favourite with rock climbers.

The Bude Formation consists mainly of deltaic and some turbidite sandstones interbedded with shales. The sandstones are relatively thick, compared with the underlying Crackington Formation, and as a result, more competent. The response to the Variscan earth movements at the end of the Carboniferous was to form more open, mostly upright or slightly asymmetric angular folds, compared with the cascades of tight recumbent folds which characterise the Crackington Formation a few kilometres to the south.