Colours of the Pilbara - Joffre shales

These lovely rocks are shales from the Joffre Member in the Brockman Formation of the Hamersley Group. The shales are approximarlty 2459 million years old. They are not usually these lovely blue, gold and purple colours. They display a slight hydrothermal alteration and it is likely their proximity to the BIF within the Brockman Formation has resulted in the precipitation of minerals leached from the iron ore.

The big bolder in the centre of the image is approximatly 1.5 feet long preventing me from rock-nabbing it and taking it home for my collection.