CIDs are a major source of cheap, high grade iron ore exploited primarily in the Pilbara and Murchison regions of Western Australia.
The erosion of this ferritic palaeosurface in the Mid Miocene transported of the iron-rich soils into the palaeodrainage system, where the iron became consolidated within the existing river courses.
It is considered that the mechanism for enrichment and formation of the goethite cortex is related to near-surface alteration of an existing highly ferruginous material by groundwater action.
The CID deposits relative lack of consolidation and proximity close to the surface in most cases renders them liable to bulk mining with little or no need for drilling and blasting.
Also, in most cases, beneficiation can increase the in-situ iron grade several percent by washing out the majority of clay, carbonate and hydrous limonite cements.
The key economic criteria for channel iron deposits are, firstly tonnage and location relative to infrastructure similar to other bulk commodities.
Rare channel iron deposits are rendered uneconomic because of a silica cement proving too durable for easy mining and crushing.
The type deposits are those at Pannawonnica and Robe River, in the Pilbara of Western Australia, which are currently mined by Rio Tinto Iron Ore. Channel iron deposits are rarer outside of the West Australian landmass, due to the relative youth of the regolith in the rest of the continental land masses, although there are smaller examples in Kazakhstan.
There is evidence of densely wooded valley fills and significant input of humic material, similar to the observed palaeoclimatic setting of the Pilbara examples.