The Iron Knob mining area (IKMA) lies at the northern end of the Middleback Ranges (MBR).
• Hosted within the Palaeoproterozoic Hutchison Group metasediments.
• Mineralization is within the Lower Middleback Iron Formation grades upwards from Carbonate Haematite to Jaspilite Haematite facies.
• Ore Formation is considered through passive supergene enrichment of Magnetite Banded Iron Formations.
• Strongest Enrichment within the LMIF Carbonate Facies – leading to complete replacement of carbonates in highest grade zones.
• The Metasediments have a history of complex deformation dominated by East – West compression.
• Mineralised zones are bounded to the East and West regional scale North – South Shear Zones.
• Multiple Stages of Archean amphibolite dykes cross cut both deposits and are influence on mineralisation and Geotechnical Parameters.
Middleback Ranges Hematite
Hematite in the MBR occurs as stratabound Palaeoproterozoic deposits of the Lower Middleback Iron Formation (LMIF), part of the Hutchison Group. The Hutchison Group forms part of the Cleve Subdomain of the Gawler Craton, and lies on its western edge. The Cleve Subdomain comprises tightly folded high-grade metamorphic rocks that are mainly derived from marine shelf sediments and mafic and acidic volcanics (Parker, 2012b).
Middleback Ranges Framework In the MBR, the Hutchison Group is composed of the Warrow Quartzite and the Middleback Subgroup. ........
