New Zealand's oldest soils

New Zealand's oldest soils

This is at Butchers Dam in Central Otago, with the snow-capped Old Man Range in the background. The soil is at least 20 million years old and would have been at the surface for most of that time. It was covered by glaciation deposits (visible at top left) about 20,000 years ago. The bright red in the subsoil indicates highly weathered iron compounds. This would have required a more tropical climate than exists today.