Contrasting alteration assemblages in metabasites from Mount Isa, Queensland; implications for copper ore genesis

Geology and Mineralogy of Uranium Deposits from Mount Isa, Australia: Implications for Albitite Uranium Deposit Models

“…The latter structures cut and displace uranium deposits and are implicated in sediment-hosted copper formation at Mount Isa [14]. Regional hydrothermal alteration within rocks of the ECV in the vicinity of Mount Isa has been extensively documented, mostly in the context of tracing flow paths for oxidised brines that formed the Mount Isa copper deposits [5][6][7]12,[15][16][17]. Of most relevance to this study are albite (± tremolite), carbonate-iron oxide and tourmaline types.…”

Mount Isa copper orebodies: improving predictive discovery

“…Hydrothermal epidote occurs predominantly in metabasalt of the Eastern Creek Volcanics and amphibolite west of the Mount Isa Fault but also in meta-sedimentary interlayers within the meta-basalt sequence (Derrick et al 1977;Wyborn 1983;Hannan et al 1993). HYMAP imagery shows that epidote is most abundant in the basal parts of the ECV sequence ( Figure 6).…”

Magmatic history of the Eastern Creek Volcanics, Mt Isa, Australia: insights from trace-element and platinum-group-element geochemistry

“…The majority of the Eastern Creek Volcanics were metamorphosed to lower to mid-greenschist facies, with amphibolite facies assemblages present only west of the Mt Isa Fault. This regional metamorphism has resulted in metabasalts that are dominated by albite, chlorite, actinolite, magnetite and varying amounts of epidote and calcite (Wyborn 1987;Bain et al 1992;Hannan et al 1993;Heinrich et al 1995). Igneous textures are preserved by the metamorphic mineralogy.…”

“…The majority of this Cu did not form sulfides but has been retained in the magma and crystallised in basaltic glass and primary oxides such as titanomagnetite (Gregory 2006). The high Cu concentrations found throughout the sequence make the Eastern Creek Volcanics an excellent metal source for hydrothermal ore deposits, and this has led to much speculation that they are the Cu source for the Mt Isa deposit (Wilson et al 1985;Wyborn 1987;Bain et al 1992;Hannan et al 1993;Heinrich et al 1995;Gregory 2006).…”

“…The basalts occur adjacent to the giant Mt Isa Cu deposit and are Cu-rich, averaging between 205 and 229 ppm in the Cromwell Metabasalt Member (Wilson et al 1985;Hannan et al 1993). This has led to suggestions that they are the source rocks for the This paper presents new platinum-group element (PGE), rare-earth element (REE) and other traceelement whole-rock geochemical data and re-assesses existing whole-rock geochemical data in order to further define the magmatic history of the Eastern Creek Volcanics.…”