The geology of Karijini’s iron ore

Hamersley Gorge with its picturesque Spa Pool in Karijini National Park in northwest Australia opens a window into the beginning of Earth, into a time when bacteria were the only inhabitants on our young planet. These colorful layers of rock are banded iron ores that formed more than 2500 million years ago at the bottom of a long-vanished ocean. At that time there was little oxygen in the ocean and no oxygen at all in the atmosphere.