Isle of Wight

Alum Bay, Isle of Wight, boasts striking multi-coloured sand cliffs from Eocene delta deposits, rich in sands, clays, and plant matter (lignite), showing near-vertical strata due to tectonic folding, sitting atop older Cretaceous chalk. The vivid colours come from iron compounds formed under different conditions, while pyrite oxidation creates browns and reds. It's a classic site showing deep time, from shallow seas to land-based deltas, revealing layers of quartz, felspar, and mica, with fossils in the limestones and clays.