| Summary: | This volume presents new data on a group of gold deposits that are hosted primarily within or in the immediate wall rocks to intrusions, and which have recently been suggested to comprise a distinct class of magmatic-hydrothermal system. These deposits have been called 'porphyry gold deposits' (Hollister 1992; Bakke 1995), 'intrusion-related stockwork-disseminated deposits' (Sillitoe 1991), 'plutonic-related gold deposits' (Newberry et al., 1988; McCoy et al., 1997) and 'intrusion-related gold deposits' (Thompson et al. 1999). Lang et al. (2000) preferred the term 'intrusion-related gold systems' because it reflects a tendency common to all magmatic-hydrothermal environments to form ores that manifest multiple styles, metal assemblages and spatial associations with their related intrusive centres. Although in its infancy, investigation and exploration of intrusion-related gold systems has accelerated markedly in the last five years, due in part to their global distribution and to the large number of deposits that contain a gold resource of >30 metric tons (Fig. 1). Major deposit examples include Fort Knox (~210 t Au), Donlin Creek (~315 t Au), Pogo (~160 t Au), and Dublin Gulch, True North and Brewery Creek (~40 t Au each) in Yukon and Alaska, as well as Mokrsko, Czech Republic (~120 t Au), Vasilkovskoe, Kazakstan (~300 t Au), Salave, Spain (~30 t Au), Korri Kollo, Bolivia (~160 t Au) and Kidston, Australia (~140 t Au). A paucity of detailed descriptions of individual intrusion-related gold systems, the plutonic provinces that host these systems, and the genetic processes critical to their formation currently limits our ability to either develop precise criteria for their definition or to formulate well-constrained geological and exploration models. The principal discussions (Sillitoe 1991; Hollister 1992; Newberry et al. 1988 and 1995; Lang et al. 1997; McCoy et al. 1997; Thompson et al. 1999; Lang et al. 2000; Goldfarb et al. 2000; Newberry 2000) suggest that there are several features common to most ...
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