Geothermal energy is becoming an increasingly hot topic. Recent research suggests that even areas outside ‘high-temperature fields’ may be sufficiently warm to generate electricity.

Rock folds are found in various shapes and sizes on Earth, and people are often amazed to see how large blocks of hard rocks have been folded like ocean waves. But fascination with folds is also shared by the petroleum industry. In Part I of this two-part article we unfold rock ‘folds’ to better understand their geometry and genesis.