30cc99ad-c166-4d46-873d-a0a27ef28217 urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2025-10-16T06:49:51 creation ISO 19115 2016 Intrusion Related Gold Deposits 30cc99ad-c166-4d46-873d-a0a27ef28217 Intrusion Related Gold Deposits (IRGD) represents a new class of mineral deposit, although still regarded as controversial (Sillitoe, 1991; Thompson et al., 1999). The consistent association of IRGDs with certain magma types, their consistent polymetallic metal associations (Au, Bi, W, As, Mo, Te and/or Sb; Lang et al., 2000), metal zonation patterns, and the presence of Au in high temperature melt inclusions associated with intrusion proximal examples indicate that a magmatic origin for IRGD can be regarded with confidence (Mustard et al., 2004). The importance of the geochemical inheritance of anomalous Au in felsic magmas (eg. Tomkins and Mavrogenes, 2003) is unclear but is probably not required, and does not explain the consistent associations between IRGD and certain granite types. Gold must be preserved in the melt fraction of crystallizing plutons and be available to the fluid phase during exsolution. Low S magmas of intermediate to felsic compositions with intermediate oxidation states favour neither early sulfide or magnetite precipitation, or early SO2 formation. The absence of these conditions should be conducive to the preservation of Au in the melt fraction of granite magmas (Blevin, 2004). Related information AGSO Journal vol.17 no. 4 - mineral deposits {"type": "Polygon", "coordinates": [[[140.0, -44.0], [155.0, -44.0], [155.0, -10.0], [140.0, -10.0], [140.0, -44.0]]]} 140.0 155.0 -44.0 -10.0 AU-QLD Earth Sciences GA Publication Other Publication Published_External economic geology geochemistry mineral deposits mineral exploration resource assessment Download the file (pdf) documentDigital Download the file (pdf) PDF Unnamed resource documentDigital HTML