| dc.creator |
Nimis, Paolo |
|
| dc.creator |
Goncharov, Alexey |
|
| dc.creator |
Ionov, Dmitri |
|
| dc.creator |
McCammon, Catherine |
|
| dc.date |
2016-05-12T17:14:00Z |
|
| dc.date |
2016-05-12T17:14:00Z |
|
| dc.date |
2015-01 |
|
| dc.date.accessioned |
2019-03-31T11:39:21Z |
|
| dc.date.available |
2019-03-31T11:39:21Z |
|
| dc.identifier |
DOI 10.1007/s00410-014-1101-8 |
|
| dc.identifier |
Contributions to Mineralogy and Petrology, January 2015, 169:6 |
|
| dc.identifier |
http://hdl.handle.net/11701/2267 |
|
| dc.identifier.uri |
https://repository.geologyscience.ru/handle/123456789/1882 |
|
| dc.description |
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. |
|
| dc.publisher |
Contributions to Mineralogy and Petrology |
|
| dc.title |
Fe3+ partitioning systematics between orthopyroxene and garnet in mantle peridotite xenoliths and implications for thermobarometry of oxidized and reduced mantle rocks |
|
| dc.type |
Article |
|