Two iron deposits, a subsurface deposit of magnetite and a surface deposit of hematite. The bulk of the surface magnetite deposit is a replacement of what originally was a simple cooling unit of an ash-flow tuff. Porosity and permeability were key factors. Because the surface hematite body, which is in approximate updip alignment with the subsurface magnetite deposit, is in reality 240 m stratigraphically higher, a fault is inferred to occur between the two deposits.--Modified journal abstract.

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