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Genesis and Targeting of BIF-hosted Iron Ore Deposits in the Yilgarn Craton

Yilgarn Craton, Western Australia

The objective of the two-year project is to determine the geological criteria that control the location of high-grade, BIF-hosted iron ore deposits in the Yilgarn and evaluate which exploration methods are most useful for their discovery.  

An opportunity to improve exploration strategies for currently under-explored Archean BIF-hosted deposits in Western Australia:

Paleoproterozoic, Superior-type BIF-hosted Fe ore deposits, such as those in the Hamersley Province (Western Australia), Transvaal Basin (South Africa), and the Quadrilatero Ferrifero (Brazil), have historically been targeted instead of Archean examples due to their larger deposit size. Consequently, Archean, Algoma-type BIF-hosted deposits in the Yilgarn Craton are less well-understood and are under-explored. However, due to the increased demand for high-grade (>~58 % Fe) iron ore concentrates, iron exploration strategies in Western Australia have recently shifted so that they now recognise the importance of Archean BIF-hosted deposits. The opportunity exists to develop more predictive exploration strategies for BIF-hosted iron ore deposits in the Yilgarn Craton.

Understand key relationships between iron ore chemistry, contaminants, and iron upgrade processes- all of which influence exploration strategies:

Research undertaken during the last decade has mostly focussed on examining (martite-microplaty hematite)-magnetite-bearing ore bodies in Paleoproterozoic, Superior-type BIF-hosted Fe ore deposits and evaluating the relative importance of supergene and hypogene processes in upgrading low-grade BIF (30 - 35 wt% Fe) to high-grade ore (e.g. Taylor et al. 2001; Dalstra et al. 2003; Dalstra and Guedes 2004; Thorne et al. 2008). In the last five years, research has moved in conjunction with the shift in exploration targeting to identify important controls on high-grade, magnetite-hematite ore bodies and their supergene-modified derivatives in Archean terranes (e.g. Koolyanobbing and Windarling, Angerer and Hagemann 2010; Weld Range deposits, Duuring and Hagemann 2010; Jack Hills, Maskell 2010). Presently, only preliminary comparisons exist for Archean versus Paleoproterozoic deposit examples (e.g. Angerer et al. 2010); these studies demonstrate important similarities between their iron ore chemistry, contaminants, and hypogene and supergene iron upgrade processes. Thus, an evaluation of iron ore-contaminant relationships, and iron upgrade processes, for Archean BIF-hosted deposits in the Yilgarn Craton will have important flow-on benefits to the understanding of Paleoproterozoic, Superior-type BIF-hosted Fe ore deposits, such as those in the Hamersley Province.

Building upon the outcomes of existing detailed deposit- and camp-scale studies on Archean BIF-hosted iron ore bodies in the Yilgarn Craton:

Several key studies have recently been completed on the characteristics and genesis of BIF-hosted Fe ore camps in the Yilgarn Craton, including Weld Range (Duuring and Hagemann 2011), Koolyanobbing and Windarling (Angerer and Hagemann 2010), Jack Hills (Maskell 2010), and Wiluna West (Lascelles 2009). The proposed project will build upon existing studies and supplement them with several new study areas (see the map insert for these locations).