Reid Keays - Academia.edu (original) (raw)

Papers by Reid Keays

Research paper thumbnail of 10th International Platinum Symposium

Platinum Metals Review, 2006

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Research paper thumbnail of The Geology of Gold Deposits

When the price of gold rose from about 200(U.S.)anouncein1979tonearly200 (U.S.) an ounce in 1979 to nearly 200(U.S.)anouncein1979tonearly700 an ounce by th... more When the price of gold rose from about 200(U.S.)anouncein1979tonearly200 (U.S.) an ounce in 1979 to nearly 200(U.S.)anouncein1979tonearly700 an ounce by the end of the same year, the gold rush of the 1980s was under way. Gold production in the western world rose dramatically; from 1981 to 1986 production increased by 300 to 1,282 metric tons per year. Annual production may reach 1,500 to 1,600 metric tons by 1990 (Woodall, 1988). The major contributors to the increased stream of gold have been Australia, Canada, Brazil, and the United States together with other circum-Pacific countries. The increased price of gold and new methods of extraction have allowed many older deposits to be reopened, but the most important factor has been the high success level of exploration. This success has resulted in large part from the application of new genetic models and from the development of new exploration techniques. There are hundreds of thousands of reported gold occurrences around the world. The majority are alluvial placers, but large numbers of bedrock occurrences have also been discovered. Most of these occurrences prove to be very small and are relatively unimportant in the overall world production level. Most mined gold has come from a small number of giant deposits, which were found by prospectors. It is becoming increasingly clear, however, that the discovery of giant deposits in the future will involve more than the sharp eyes and persistence of the old prospector. The use of sound geologic principles, and exploration programs based on those principles, is what the future holds. An example can be seen in the successful search for gold deposits in the South Pacific. There, exploration models have been based on principles developed in the study of modern geothermal systems. Giant deposits such as Lihir and Porgera have been the reward. Another example is the giant copper-gold-uranium deposit at Olympic Dam, South Australia, discovered beneath 300 m of cover using an exploration program based on models developed by Western Mining Corporation geologists for Zambian copper belt-type deposits. Gold deposits are widely dispersed throughout many geologic settings and in virtually all kinds of rocks, but they do not seem to have formed at a uniform rate throughout geologic history. On the contrary, two very distinct metallogenic periods have been defined. The first is the Archean era, when most of the great deposits in greenstone belts were formed and the vast Witwatersrand basin deposits in

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Research paper thumbnail of Neutron activation analysis for trace elements. Elements depleted on lunar surface - Implications for origin of moon and meteorite influx rate Final report, 1 Aug. 1969 - 31 Jan. 1971

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Research paper thumbnail of Geochemistry of the igneous rocks of the Belingwe Greenstone Belt: Alteration, contamination and petrogenesis

The Geology of the Belingwe Greenstone Belt, Zimbabwe

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Research paper thumbnail of Exploration for Komatiite-Associated Ni-Cu-(PGE) Mineralization in the Thompson Nickel Belt, Manitoba

The Challenge of Finding New Mineral Resources<subtitle>Global Metallogeny, Innovative Exploration, and New Discoveries</subtitle>, 2010

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Research paper thumbnail of Origin and depositional history of platinum-group minerals in placers – A critical review of facts and fiction

Ore Geology Reviews, 2022

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Research paper thumbnail of And Ore-Associated Komatiites

Most komatiite-associated magmatic Ni–Cu–(PGE) sulfide deposits formed from sulfide-undersaturate... more Most komatiite-associated magmatic Ni–Cu–(PGE) sulfide deposits formed from sulfide-undersaturated magmas and are interpreted to have formed in dynamic lava channels or magma conduits by incorporation of crustal sulfur. They commonly exhibit geochemical and isotopic evidence of crustal contamination and chalcophile element depletion on the scale of individual cooling units or parts of individual cooling units that appear to be associated with the ore-forming process. It is possible, there-fore, to discriminate between rocks generated during ore-forming processes and rocks generated during normal igneous processes by identifying signatures characteristic of crustal contamination (e.g., Th–U–LREE enrichment, negative Nb–Ta–Ti anomalies) or sulfide segregation (e.g., Co–Ni–Cu–PGE depletion) (or both) and distinguishing them from signatures characteristic of nor-mal igneous fractionation or accumulation of crystals. The amounts of contamination and chalcophile element depletion pro-duce...

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Research paper thumbnail of Petrogenesis of the Permian Luotuoshan sulfide-bearing mafic-ultramafic intrusion, Beishan Orogenic Belt, NW China: evidence from whole-rock Sr–Nd–Pb and zircon Hf isotopic geochemistry

Journal of Geochemical Exploration, 2022

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Research paper thumbnail of Trace element lithophile and chalcophile element geochemistry, petrogenesis and metallogenesis of komatiites at Kambalda, Western Australia

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Research paper thumbnail of Constraints on the genesis of Huronian magmatism in the Sudbury area from radiogenic isotopic and geochemical evidence

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Research paper thumbnail of Project 97012; Cu-Ni-PGE in Nipissing Diabase; results from surface and core samples

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Research paper thumbnail of Nature, Genesis, and Tectonic Setting of Mesothermal Gold Mineralization in the Yilgarn Block, Western Australia

The Geology of Gold Deposits, 1989

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Research paper thumbnail of Geological and geochemical relationships between the contact sublayer, offsets, and main mass of the Sudbury igneous complex

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Research paper thumbnail of Platinum-group element mineralization in Paleoproterozoic basic intrusions in central and northeastern Ontario, Canada

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Research paper thumbnail of Project Unit 93-08; Geology and geochemistry of the Totten Mine section of the Worthington Offset, Sudbury igneous complex, Ontario

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Research paper thumbnail of Neutron activation analysis for trace elements. Elements depleted on lunar surface - Implications for origin of moon and meteorite influx rate Final report, 1 Aug. 1969 - 31 Jan. 1971

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Research paper thumbnail of Mineral potential of the Nipissing gabbro

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Research paper thumbnail of The geology, geochemistry, and mineralization of the Agnew (Shakespeare-Dunlop) Intrusion, Sudbury region, Canada

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Research paper thumbnail of Re-Os isotope geochemistry of Tertiary picritic and basaltic magmatism of east Greenland: Constraints on plume-lithosphere interactions and the genesis of the Platinova Reef

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Research paper thumbnail of Stratigraphic correlation and structure of the Agnew and East Bull Lake intrusions; implications for the evolution of the Palaeoproterozoic Huronian rift zone in central Ontario

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Research paper thumbnail of 10th International Platinum Symposium

Platinum Metals Review, 2006

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Research paper thumbnail of The Geology of Gold Deposits

When the price of gold rose from about 200(U.S.)anouncein1979tonearly200 (U.S.) an ounce in 1979 to nearly 200(U.S.)anouncein1979tonearly700 an ounce by th... more When the price of gold rose from about 200(U.S.)anouncein1979tonearly200 (U.S.) an ounce in 1979 to nearly 200(U.S.)anouncein1979tonearly700 an ounce by the end of the same year, the gold rush of the 1980s was under way. Gold production in the western world rose dramatically; from 1981 to 1986 production increased by 300 to 1,282 metric tons per year. Annual production may reach 1,500 to 1,600 metric tons by 1990 (Woodall, 1988). The major contributors to the increased stream of gold have been Australia, Canada, Brazil, and the United States together with other circum-Pacific countries. The increased price of gold and new methods of extraction have allowed many older deposits to be reopened, but the most important factor has been the high success level of exploration. This success has resulted in large part from the application of new genetic models and from the development of new exploration techniques. There are hundreds of thousands of reported gold occurrences around the world. The majority are alluvial placers, but large numbers of bedrock occurrences have also been discovered. Most of these occurrences prove to be very small and are relatively unimportant in the overall world production level. Most mined gold has come from a small number of giant deposits, which were found by prospectors. It is becoming increasingly clear, however, that the discovery of giant deposits in the future will involve more than the sharp eyes and persistence of the old prospector. The use of sound geologic principles, and exploration programs based on those principles, is what the future holds. An example can be seen in the successful search for gold deposits in the South Pacific. There, exploration models have been based on principles developed in the study of modern geothermal systems. Giant deposits such as Lihir and Porgera have been the reward. Another example is the giant copper-gold-uranium deposit at Olympic Dam, South Australia, discovered beneath 300 m of cover using an exploration program based on models developed by Western Mining Corporation geologists for Zambian copper belt-type deposits. Gold deposits are widely dispersed throughout many geologic settings and in virtually all kinds of rocks, but they do not seem to have formed at a uniform rate throughout geologic history. On the contrary, two very distinct metallogenic periods have been defined. The first is the Archean era, when most of the great deposits in greenstone belts were formed and the vast Witwatersrand basin deposits in

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Research paper thumbnail of Neutron activation analysis for trace elements. Elements depleted on lunar surface - Implications for origin of moon and meteorite influx rate Final report, 1 Aug. 1969 - 31 Jan. 1971

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Geochemistry of the igneous rocks of the Belingwe Greenstone Belt: Alteration, contamination and petrogenesis

The Geology of the Belingwe Greenstone Belt, Zimbabwe

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Exploration for Komatiite-Associated Ni-Cu-(PGE) Mineralization in the Thompson Nickel Belt, Manitoba

The Challenge of Finding New Mineral Resources<subtitle>Global Metallogeny, Innovative Exploration, and New Discoveries</subtitle>, 2010

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Research paper thumbnail of Origin and depositional history of platinum-group minerals in placers – A critical review of facts and fiction

Ore Geology Reviews, 2022

Bookmarks Related papers MentionsView impact

Research paper thumbnail of And Ore-Associated Komatiites

Most komatiite-associated magmatic Ni–Cu–(PGE) sulfide deposits formed from sulfide-undersaturate... more Most komatiite-associated magmatic Ni–Cu–(PGE) sulfide deposits formed from sulfide-undersaturated magmas and are interpreted to have formed in dynamic lava channels or magma conduits by incorporation of crustal sulfur. They commonly exhibit geochemical and isotopic evidence of crustal contamination and chalcophile element depletion on the scale of individual cooling units or parts of individual cooling units that appear to be associated with the ore-forming process. It is possible, there-fore, to discriminate between rocks generated during ore-forming processes and rocks generated during normal igneous processes by identifying signatures characteristic of crustal contamination (e.g., Th–U–LREE enrichment, negative Nb–Ta–Ti anomalies) or sulfide segregation (e.g., Co–Ni–Cu–PGE depletion) (or both) and distinguishing them from signatures characteristic of nor-mal igneous fractionation or accumulation of crystals. The amounts of contamination and chalcophile element depletion pro-duce...

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Research paper thumbnail of Petrogenesis of the Permian Luotuoshan sulfide-bearing mafic-ultramafic intrusion, Beishan Orogenic Belt, NW China: evidence from whole-rock Sr–Nd–Pb and zircon Hf isotopic geochemistry

Journal of Geochemical Exploration, 2022

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Trace element lithophile and chalcophile element geochemistry, petrogenesis and metallogenesis of komatiites at Kambalda, Western Australia

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Constraints on the genesis of Huronian magmatism in the Sudbury area from radiogenic isotopic and geochemical evidence

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Project 97012; Cu-Ni-PGE in Nipissing Diabase; results from surface and core samples

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Nature, Genesis, and Tectonic Setting of Mesothermal Gold Mineralization in the Yilgarn Block, Western Australia

The Geology of Gold Deposits, 1989

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Geological and geochemical relationships between the contact sublayer, offsets, and main mass of the Sudbury igneous complex

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Platinum-group element mineralization in Paleoproterozoic basic intrusions in central and northeastern Ontario, Canada

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Project Unit 93-08; Geology and geochemistry of the Totten Mine section of the Worthington Offset, Sudbury igneous complex, Ontario

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Neutron activation analysis for trace elements. Elements depleted on lunar surface - Implications for origin of moon and meteorite influx rate Final report, 1 Aug. 1969 - 31 Jan. 1971

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Mineral potential of the Nipissing gabbro

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The geology, geochemistry, and mineralization of the Agnew (Shakespeare-Dunlop) Intrusion, Sudbury region, Canada

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Re-Os isotope geochemistry of Tertiary picritic and basaltic magmatism of east Greenland: Constraints on plume-lithosphere interactions and the genesis of the Platinova Reef

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Stratigraphic correlation and structure of the Agnew and East Bull Lake intrusions; implications for the evolution of the Palaeoproterozoic Huronian rift zone in central Ontario

Bookmarks Related papers MentionsView impact