Folds From http://www.geosci.unc.edu/faculty/glazner/I mages/Structure/Folds.html Barstow syncline, a beautiful fold in Miocene shales and sandstones, Rainbow Basin, Mojave Desert, California. This fold formed at a bend in a strike-slip fault. Folds near Calico ghost town, northeast of Barstow, Mojave Desert, California. Like the Barstow syncline, these folds formed at a bend in a strike-slip fault. Their axes strike east-west, indicating that the forces that deformed the rocks squeezed from the north and south. Isoclinal folds in dolomitic marble, Mosaic Canyon, Death Valley. The student has his fingers on the same layer, which can be traced around a fold hinge to the left. A fold lying on its side like this is called "recumbent". Complicated folds near Calico ghost town, Mojave Desert. Field of view is about 3 m wide. Differential movement of layers above and below the chaotic zone crumpled the thinly bedded central layers. Just left of center a small anticline-syncline pair has broken along a thrust fault with a few cm displacement. Can you see the recumbent fold in the lower right? A classic monocline near Mexican Hat, Utah. Mesozoic strata are bowed down along the fold. they are horizontal on the plateau at left and in the foreground but dip 45 degrees or more along the fold.