The geology of Maria Island is of great interest as it contains features from many geological ages. The Triassic sandstones of the Painted Cliffs is one such feature.
Although this sort of rock formation is not uncommon, it is rare in a natural situation for it to be so extensively and beautifully exposed. The wonderful patterns are caused by ground water percolating down through the already formed sandstone and leaving traces of iron oxides, which have stained the rock formation. This probably occurred millions of years ago in a monsoonal climate.