title: Fe3+ partitioning systematics between orthopyroxene and garnet in mantle peridotite xenoliths and implications for thermobarometry of oxidized and reduced mantle rocks
metadata.name: dc.contributor.author
metadata.value: Nimis, Paolo
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Goncharov, Alexey
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Ionov, Dmitri
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: McCammon, Catherine
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2016-05-12T17:14:00Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2016-05-12T17:14:00Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2015-01
metadata.lang: -
metadata.name: dc.identifier
metadata.value: DOI 10.1007/s00410-014-1101-8
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: Contributions to Mineralogy and Petrology, January 2015, 169:6
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/2267
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: We have investigated the partitioning of Fe3+ between orthopyroxene (Opx) and garnet (Grt) in well-equilibrated mantle xenoliths using Mössbauer spectroscopy. The samples cover a wide range of P–T conditions (2.1–6.6 GPa, 690–1,412 °C) and geothermal gradients, and are thus representative for Earth’s upper mantle in both on-craton and off-craton continental settings. Garnet has Fe3+/Fetot ratios of 0.03–0.13 and Fe2O3 contents of 0.24–1.00 wt%. Orthopyroxene has, on average, lower Fe3+/Fetot ratios (0.01–0.09) and Fe2O3 contents (0.05–0.63 wt%). In low-pressure, high-temperature samples, however, Opx is systematically richer in Fe2O3 than the coexisting Grt. The Fe3+ Opx/Grt partition coefficient (DOpx/GrtFe3+)(DFe3+Opx/Grt) shows no obvious relationship with temperature, but increases with decreasing pressure and with increasing NaOpx. The observed Opx/Grt Fe3+ systematics imply that the Opx–Grt Fe–Mg exchange thermometer is not robust against redox changes if total Fe is treated as Fe2+. An approximate evaluation of errors on T estimates due to redox effects predicts negligible deviations for strongly reduced conditions (<65 °C), but potentially large deviations (> to ≫100 °C) for strongly oxidized conditions, especially at very high pressure and when both P and T are calculated by iteration.
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: Contributions to Mineralogy and Petrology
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Fe3+ partitioning systematics between orthopyroxene and garnet in mantle peridotite xenoliths and implications for thermobarometry of oxidized and reduced mantle rocks
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: CTMP-D-14-00145-2.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/2267/1/CTMP-D-14-00145-2.pdf
resources.format: Adobe PDF
resources.size: 1,33 MB