Experimental calibration of a new oxybarometer for silicic magmas based on vanadium partitioning between magnetite and silicate melt
Experimental calibration of a new oxybarometer for silicic magmas based on vanadium partitioning between magnetite and silicate melt
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基于磁铁矿和硅酸盐熔体之间钒分配的新型硅质岩浆氧压计的实验校准
DOI：
10.1016/j.gca.2017.04.020
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发表时间：
2017
影响因子：
5
通讯作者：
Audétat A.
中科院分区：
文献类型：
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作者：
Arató R;Audétat A.
实验测定了钒在磁铁矿-流纹质硅酸盐熔体间的分配系数DVMgt/熔体，并与氧逸度进行了关系（铁橄榄石-磁铁矿-石英缓冲层上方0.7-4.0 log单位），温度（800-1000° C）、熔融氧化铝饱和指数（ASI= 0.74-1.14）、磁铁矿组成（0.2- 14wt%TiO 2）和压力（1-5 kbar;在H2O饱和时）。通过平衡小的（≤ 20 µm），无V的磁铁矿颗粒在V掺杂的硅酸盐熔体（≤ 100 ppm V）中进行实验，然后通过LA-ICP-MS分析两相。结果表明，DVMgt/melt强烈地依赖于fO 2，从MnO-Mn 3 O 4缓冲区到Ni-NiO缓冲区增加了1.5-1.7个对数单位，从Ni-NiO缓冲区到MnO-Mn 3 O 4缓冲区增加了1.5-1.7个对数单位，从MnO-Mn 3 O 4缓冲区到Ni-NiO缓冲区增加了1.5-1.7个对数单位，从MnO-Mn 3 O 4缓冲区到Ni-NiO缓冲区增加了1.5 - 1.7个对数单位，从MnO-Mn 3 O 4缓冲区到Ni-NiO缓冲区增加了1.5-1.7个对数单位。（但仍相当大）程度上影响熔融氧化铝饱和指数（ASI;在0.4 ASI单位上增加0.3-0.7 log单位）和温度（在固定fO 2缓冲液下在200° C间隔上增加0.3-0.7 log单位）。磁铁矿成分和熔体水含量似乎有可以忽略不计的影响。通过以下线性回归方程拟合数据：log D V mgt/melt= 0.3726 × 10，000 T+ 2.0465 Ω ASI-0.4773 Ω Δ FMQ-2.1214，其中温度以K给出，ASI是指摩尔Al 2 O3/（CaO+ Na 2 O+ K2 O），ΔFMQ是指fO 2（log单位）与铁橄榄石-磁铁矿-石英缓冲层的偏差。这个方程重现了我们所有的数据在0.3个对数单位，其中89%在0.15个对数单位。这种新的氧气压计相对于经典的磁铁矿-钛铁矿氧气压计的主要优点是：（1）它可以应用于不含钛铁矿的岩石，以及（2）它更容易应用于缓慢冷却的岩石，如花岗岩。
Partition coefficients of vanadium between magnetite and rhyolitic silicate melt, D V mgt/melt, were experimentally determined as a function of oxygen fugacity (0.7–4.0 log units above the fayalite-magnetite-quartz buffer), temperature (800–1000° C), melt alumina saturation index (ASI= 0.74–1.14), magnetite composition (0.2–14 wt% TiO 2) and pressure (1–5 kbar; at H 2 O saturation). Experiments were performed by equilibrating small (≤ 20 µm), V-free magnetite grains in V-doped silicate melts (∼ 100 ppm V) and then analyzing both phases by LA-ICP-MS. Attainment of equilibrium was demonstrated by several reversal experiments. The results suggest that D V mgt/melt depends strongly on fO 2, increasing by 1.5–1.7 log units from the MnO-Mn 3 O 4 buffer to the Ni-NiO buffer, and to lesser (but still considerable) extents on melt alumina saturation index (ASI; increasing by 0.3–0.7 log units over 0.4 ASI units) and temperature (increasing by 0.3–0.7 log units over a 200° C interval at a fixed fO 2 buffer). Magnetite composition and melt water content seem to have negligible effects. The data were fitted by the following linear regression equation: log D V mgt/melt= 0.3726∗ 10, 000 T+ 2.0465∗ ASI-0.4773∗ Δ FMQ-2.1214, in which temperature is given in K, ASI refers to molar Al 2 O 3/(CaO+ Na 2 O+ K 2 O) and ΔFMQ refers to the deviation of fO 2 (in log units) from the fayalite-magnetite-quartz buffer. This equation reproduces all of our data within 0.3 log units, and 89% of them within 0.15 log units. The main advantages of this new oxybarometer over classical magnetite–ilmenite oxybarometry are (1) that it can be applied to rocks that do not contain ilmenite, and (2) that it is easier to apply to slowly-cooled rocks such as granites.
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发表时间：
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期刊：
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影响因子：
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作者：
DoN. lr;H. LrNosr-pv;B. RoNu;O. Fnosr
通讯作者：
DoN. lr;H. LrNosr-pv;B. RoNu;O. Fnosr
铁在过铝、偏铝和过碱硅酸盐熔体中的结构作用和均匀氧化还原平衡
影响因子：
3.5
作者：
M. Dickenson;Paul C. Hess
通讯作者：
Paul C. Hess
500 MPa水压下硅熔体中铁的氧化态
DOI：
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发表时间：
2002
期刊：
影响因子：
--
作者：
M. Wilke;H. Behrens;D. Burkhard;S. Rossano
通讯作者：
S. Rossano
影响因子：
5.3
作者：
Canil, D
通讯作者：
Canil, D