Crust-mantle interaction and genesis of the Kidston gold-rich breccia pipe deposit in north-east Australia

U-Pb, Hf and Os isotope evidence

Valeria Murgulov*, William L. Griffin, Suzanne Y. O'Reilly

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

Abstract

Hf model ages yielded by rutile grains in a lower-crustal granulite xenolith provide evidence for intrusion of basaltic magmas into and below the lower crust around 420 Ma and 1,570 Ma. A host rock to the Kidston gold-rich deposit in the north-eastern Australian craton, the Oak River Granodiorite (U-Pb crystallisation age of 418 +/- 2 Ma), formed by remelting of the heterogeneous ca. 1,550 Ma crust (initial Hf-176/Hf-177 from 0.28228 to 0.28167) that may have been produced by mixing of mantle-derived magmas with the melting products of 1,935 Ma to 3,260 Ma crustal rocks. The Kidston gold-rich Median Dyke (336 +/- 4 Ma) is contemporaneous with the Lochaber Granite (338 +/- 3 Ma) within a spatially associated magmatic complex. However, the less radiogenic Hf-isotope compositions of zircons in the Median Dyke (0.28234 to 0.28211) than in the Lochaber Granite (0.28253 to 0.28234) suggest mixing between Lochaber Granite magmas and magmas derived by remelting of the Oak River Granodiorite. The Os model age of a sulfide grain in a mantle-derived Iherzolite xenolith records a metasomatic event in the lithospheric mantle around 350 Ma related to back-arc extension; however, no juvenile mantle input was required to produce the Median Dyke magmas.

Original languageEnglish
Title of host publicationMineral deposit research for a high-tech world
Subtitle of host publicationproceedings of the 12th Biennial SGA Meeting
EditorsErik Jonsson
Place of PublicationUppsala
PublisherSGU-SVERIGES GEOLOGISKA UNDERSOKNING-GEOLOGY SURVEY SWEDEN
Pages228-231
Number of pages4
ISBN (Print)9789174032079
Publication statusPublished - 2013
Event12th Biennial SGA Meeting: Mineral Deposit Research for a High-Tech World - Uppsala, Sweden
Duration: 12 Aug 201315 Aug 2013

Conference

Conference12th Biennial SGA Meeting
CountrySweden
CityUppsala
Period12/08/1315/08/13

Keywords

  • Crust-mantle interaction
  • zircon and rutile Hf isotopes
  • sulfide Os isotopes
  • Kidston deposit
  • north-east Australia

Cite this

Murgulov, V., Griffin, W. L., & O'Reilly, S. Y. (2013). Crust-mantle interaction and genesis of the Kidston gold-rich breccia pipe deposit in north-east Australia: U-Pb, Hf and Os isotope evidence. In E. Jonsson (Ed.), Mineral deposit research for a high-tech world: proceedings of the 12th Biennial SGA Meeting (pp. 228-231). Uppsala: SGU-SVERIGES GEOLOGISKA UNDERSOKNING-GEOLOGY SURVEY SWEDEN.