Conference Proceedings
PACRIM 2015
Conference Proceedings
PACRIM 2015
Platinum Group Elements in the Baima and Taihe Fe-Ti Oxide-bearing Gabbroic Intrusions of Emeishan Large Igneous Province and Problems on Propensity of Magma Series for Sulfide- versus Oxide-dominated Deposit Types
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A full-length paper was notprepared for this presentation._x000D_
The Emeishan large igneous province (ELIP) of SW China is host to magmatic Ni-Cu-(PGE) sulfide and Fe-Ti-V oxide deposits which contain economic to subeconomic concentrations of precious and base metals. The formation of a given deposit-type (ie sulfide versus oxide) is thought to be related to the type of parental magma (ie high-Ti versus low-Ti) and the subsequent processes (ie fractional crystallisation and sulfide segregation), which allowed for metal enrichment.We examined the PGE of Baima and Taihe oxide-bearing layered mafic intrusions from the ELIP (Shellnutt, Ma and Qi, in press), and compared them with the nearby Xinjie and Hongge intrusions as well as with the Emeishan flood basalts. The PGE results for the two intrusions are contrasting. The Baima gabbroic rocks are almost PGE-barren (PGE < 4 ppb) whereas the Taihe gabbroic rocks are variable, but generally much higher in PGE concentrations (PGE < 2 to ~300 ppb), although the gabbros from both intrusions are enriched in platinum-subgroup PGE (PPGE = Rh, Pt and Pd) relative to iridium-subgroup PGE (IPGE = Os, Ir and Ru). Cu/Zr, Ni/Ir, Y/Pt, Cu/Pd and Ni/Ir systematics suggest that the Baima rocks were derived from a relatively evolved, mafic, S-undersaturated parental magma that was affected by earlier sulfide segregation. In contrast, the Taihe rocks record evidence of both S-saturated and S-undersaturated conditions and that the parental magma was likely emplaced very close to S-saturation. Through comparison of the PGE contents in the Emeishan flood basalts and the Emeishan oxide-bearing intrusions, we provide a self-consistent model for ELIP that the PGE budget in a magma is not strictly controlled by magma series (high-Ti versus low-Ti), but very much by crustal contamination.CITATION:Ma, G, Shellnutt, J G and Qi, L, 2015. Platinum group elements in the Baima and Taihe Fe-Ti oxide-bearing gabbroic intrusions of emeishan large igneous province and problems on propensity of magma series for sulfide- versus oxide-dominated deposit types, in Proceedings PACRIM 2015 Congress, pp 303-310 (The Australasian Institute of Mining and Metallurgy: Melbourne).
A full-length paper was notprepared for this presentation._x000D_
The Emeishan large igneous province (ELIP) of SW China is host to magmatic Ni-Cu-(PGE) sulfide and Fe-Ti-V oxide deposits which contain economic to subeconomic concentrations of precious and base metals. The formation of a given deposit-type (ie sulfide versus oxide) is thought to be related to the type of parental magma (ie high-Ti versus low-Ti) and the subsequent processes (ie fractional crystallisation and sulfide segregation), which allowed for metal enrichment.We examined the PGE of Baima and Taihe oxide-bearing layered mafic intrusions from the ELIP (Shellnutt, Ma and Qi, in press), and compared them with the nearby Xinjie and Hongge intrusions as well as with the Emeishan flood basalts. The PGE results for the two intrusions are contrasting. The Baima gabbroic rocks are almost PGE-barren (PGE < 4 ppb) whereas the Taihe gabbroic rocks are variable, but generally much higher in PGE concentrations (PGE < 2 to ~300 ppb), although the gabbros from both intrusions are enriched in platinum-subgroup PGE (PPGE = Rh, Pt and Pd) relative to iridium-subgroup PGE (IPGE = Os, Ir and Ru). Cu/Zr, Ni/Ir, Y/Pt, Cu/Pd and Ni/Ir systematics suggest that the Baima rocks were derived from a relatively evolved, mafic, S-undersaturated parental magma that was affected by earlier sulfide segregation. In contrast, the Taihe rocks record evidence of both S-saturated and S-undersaturated conditions and that the parental magma was likely emplaced very close to S-saturation. Through comparison of the PGE contents in the Emeishan flood basalts and the Emeishan oxide-bearing intrusions, we provide a self-consistent model for ELIP that the PGE budget in a magma is not strictly controlled by magma series (high-Ti versus low-Ti), but very much by crustal contamination.CITATION:Ma, G, Shellnutt, J G and Qi, L, 2015. Platinum group elements in the Baima and Taihe Fe-Ti oxide-bearing gabbroic intrusions of emeishan large igneous province and problems on propensity of magma series for sulfide- versus oxide-dominated deposit types, in Proceedings PACRIM 2015 Congress, pp 303-310 (The Australasian Institute of Mining and Metallurgy: Melbourne).
Contributor(s):
G Ma, J G Shellnutt, L Qi
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Platinum Group Elements in the Baima and Taihe Fe-Ti Oxide-bearing Gabbroic Intrusions of Emeishan Large Igneous Province and Problems on Propensity of Magma Series for Sulfide- versus Oxide-dominated Deposit TypesPDFThis product is exclusive to Digital library subscription
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Platinum Group Elements in the Baima and Taihe Fe-Ti Oxide-bearing Gabbroic Intrusions of Emeishan Large Igneous Province and Problems on Propensity of Magma Series for Sulfide- versus Oxide-dominated Deposit TypesPDFNormal price $22.00Member price from $0.00
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- Published: 2015
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