Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.14/191175
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- Title
- Evidence for modern-style subduction to 3.1 Ga : a plateau-adakite-gold (diamond) association
- Related
- Kent C. Condie; Victoria Pease. When did plate tectonics begin on planet Earth?, p.129-148
- Publisher
- Colorado, USA : Geological Society of America
- Date
- 2008
- FoR/RFCD Code(s)
-
040300 Geology
040400 Geophysics
- Author/Creator
- Wyman, D. A
- Author/Creator
- O'Neill, C
- Author/Creator
- Ayer, J. A
- Description
- The distribution of lamprophyre-hosted Neoarchean diamond deposits in the southem Superior Province, Canada, corresponds to that of coeval giant(> 100 tAu) examples of "orogenic" gold deposits, which are typically associated with quartz-carbonate veining. This common association in the southern Superior Province, and at Yellowknife in the Slave craton, suggests that the occurrence of both diamonds and gold was promoted by the same geodynamic factors. A previously proposed subduction diamond model invokes flat subduction of buoyant oceanic plateau crust as the only means of entraining diamonds in shoshonitic lamprophyres, which are generally derived from relatively shallow mantle depths. Computer modeling of the thermal evolution and dehydration processes associated with this tectonic scenario clarifies observations made in presentday flat subduction settings and suggests many factors that should enhance the hydrothermal mineralization systems responsible for Archean and post-Archean orogenic gold deposits. The case for links among mantle plume-derived oceanic plateaus, crustal growth, and anomalously large gold deposits is strengthened by the newly recognized association of oxidized granites, lamprophyres, and diamonds at 3.1 Ga in the Kaapvaal craton and by evidence for similar recurring gold-diamond ± lamprophyre associations throughout the geologic record, including the Mother Lode deposits of California.
- Description
- 20 page(s)
- Subject Keyword
- 040300 Geology
- Subject Keyword
- 040400 Geophysics
- Resource Type
- book chapter
- Organisation
- Macquarie University. National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC)
- Identifier
- http://hdl.handle.net/1959.14/191175
- Identifier
- ISBN:9780813724409
- Identifier
- mq-rm-2007011144
- Language
- eng
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