The genesis of the Mount Goldsworthy iron ore deposits of northwest Australia

The deposits are of three types. Lode-type deposits are deep, narrow, conformable lenses of massive hematite within steeply-dipping Precambrian iron formation. They are believed to be hypogene replacements of the iron formation, formed by hot fluids during metamorphism; they contain much less alumina and phosphorus than supergene ores, their structural relations suggest formation after deformation, and they have 'mudstone' envelopes that suggest argillic alteration. Crust-type deposits are relatively shallow bodies formed by supergene enrichment (leaching of silica). Derived-type deposits are products of mechanical and chemical weathering, transportation, and accumulation of iron from the iron formation. Examples of all three types occur in other countries.

This record provided courtesy of AGI/GeoRef.