The dark bands seen between the rock layers are goethite, an iron oxide mineral that forms through the oxidation of iron-rich fluids along bedding planes or fractures in the rock.
Located within the Merinjina Tillite Formation, the smaller embedded rocks were likely deposited in this massive matrix by glacial activity. This tillite has since undergone oxidation, and in some areas, has been partially replaced by botryoidal goethite—a rounded form of iron oxide.
