DIRK WIERSMA / SCIENCE PHOTO LIBRARY DIRK WIERSMA / SCIENCE PHOTO LIBRARY
Ptygmatic folds in gneiss rock. Gneiss is a metamorphic rock, formed when igneous or sedimentary rock is subjected to high temperatures and pressures within the Earth's crust. This separates the minerals into layers or bands. While the rock is in a slightly molten, plastic state, it can be randomly deformed, causing meandering ptygmatic folding, as seen here. This polished sample measures 375 by 500 millimetres.
Model release not required. Property release not required.