Two examples of plumose structure, beautifully expressed in a small boulder of the Helena Formation (Mesoproterozoic limestone from the Belt Supergroup) in Glacier National Park, Montana. Photo by Bob L'Hommedieu.
A concretion somewhere in the Bisti Badlands of New Mexico. : pics
Classic textbook normal fault - with typical posing geologist
Ptygmatic Folds: typical of slump folding/ migmatites/ decollement detachment zones, ptygmatic folds generally represent conditions where the folded material is of much greater viscosity than the surrounding medium
Small thrust fault and fold in sandstone, southern Oregon (flower structure?).