Folding at Broadhaven
Pembrokeshire, SW Wales
One of The Geological Society's 100 Great Geosites. Asymmetric folds in interbedded Carboniferous siltstones, shales and coal horizons are cut here by a number of northward-propagating thrusts. This classic structure has been studied in some detail (e.g. Williams and Chapman,1983) as it provides an excellent outcrop example to examine the interplay between faulting and folding during deformation.
Trevayne
Pembrokeshire, SW Wales
Large-scale harmonic fold within Carboniferous siltstones, shales and coal horizons. Close inspection of the fold core reveals several low offset thrust segments which probably formed to accommodate the relatively tight interlimb angle here. The cross-section below shows the transition in structural style between this location, Monkstone Point and Saundersfoot.
Trevayne
Pembrokeshire, SW Wales
Large-scale harmonic fold within Carboniferous siltstones, shales and coal horizons. Close inspection of the fold core reveals several low offset thrust segments which probably formed to accommodate the relatively tight interlimb angle here. The cross-section below shows the transition in structural style between this location, Monkstone Point and Saundersfoot.
Folding and faulting, Saundersfoot
Pembrokeshire, SW Wales
Saundersfoot is one of the most well-known outcrops in the UK and an important site for training future geoscientists. Carboniferous rocks of the South Wales Lower Coal Measures were folded and faulted here during the Variscan Orogeny.
Inspect the outcrop and examine the interaction between faults and folds. The detailed virtual outcrops below show a section close to Saundersfoot where a small-scale fold has been decapitated and transported onto another. This relationship implies that folding here occurred before thrusting. This relationship is not clear everywhere: different parts of the outcrop show different deformation histories. In short, deformation here was complex. There does not appear to be any systematic relationship between the timing of folding and faulting.
Compare the complex deformation structures here to Amroth, just a few miles to the north, where units of a similar age and depositional setting are relatively undeformed.
Lat: 51°42'27.6"N Long: 4°41'44.0"W
Virtual outcrop generated using Agisoft Photoscan from 372 photographs acquired by Yuki Totake with a Nikon D3200.