Partitioning of trace elements between garnet, clinopyroxene and diamond-forming carbonate-silicate melt at 7 GPa

2010 ◽  
Vol 74 (2) ◽  
pp. 227-239 ◽  
Author(s):  
A. V. Kuzyura ◽  
F. Wall ◽  
T. Jeffries ◽  
Yu. A. Litvin
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Element Distribution ◽  
Silicate Melt ◽  
Trace Element Distribution ◽  
Published Data ◽  
Trace Element Partitioning ◽  
Element Partitioning ◽  
Icp Ms ◽  
Melt Composition

AbstractConcentrations of trace elements in coexisting garnet, clinopyroxene and completely miscible carbonate-silicate melt (formed at 7 GPa from the Chagatai silicocarbonatite rock known to be diamondiferous) were determined using LA-ICP-MS. The partition coefficients for Li, Rb, Cs, Ba, Th, U, Ta, Nb, La, Ce, Pb, Pr, Sr, Nd, Zr, Hf, Sm, Eu, Gd, Tb, Dy, Y, Ho, Er, Tm, Yb, Lu, Sc and Zn were determined. The new experimental data for trace-element partitioning between garnet, clinopyroxene and carbonate-silicate melt have been compared with published data for partitioning between garnet, clinopyroxene and carbonatite melt, and garnet, clinopyroxene and silicate melt. The results show that the trace-element partitioning is not significantly altered by changes in melt composition, with HREE always concentrated in the garnet. Carbonate-silicate melt, as a diamond-forming medium, and carbonatite or silicate melt equilibrated with mantle silicate minerals, behave similarly in respect of trace-element distribution.

Partitioning of V and 19 other trace elements between rutile and silicate melt as a function of oxygen fugacity and melt composition: Implications for subduction zones

2020 ◽  
Vol 105 (2) ◽  
pp. 244-254 ◽  
Author(s):  
Megan Holycross ◽  
Elizabeth Cottrell
Keyword(s):  
Trace Elements ◽  
Subduction Zones ◽  
Silicate Melt ◽  
High Field Strength ◽  
Trace Element Partitioning ◽  
Element Partitioning ◽  
Oxygen Buffer ◽  
Melt Composition ◽  
Refractory Slab ◽  
Partitioning Behavior

Abstract Vanadium is a multivalent element that can speciate as V2+, V3+, V4+, and V5+ over a range of geologically relevant oxygen fugacities (fO2). The abundance of V in planetary materials can be exploited as a proxy for fO2 when its partitioning behavior is known. The mineral rutile (TiO2) is an important carrier of the high field strength elements Nb and Ta in the solid Earth, but it can also incorporate substantial quantities of vanadium (up to ~2000 ppm; e.g., Zack et al. 2002). However, little work has been done to systematically investigate how the partitioning of V in rutile-bearing systems changes as a function of both fO2 and composition. We measured the partitioning of V and 19 other trace elements (Sc, Cr, Y, Zr, Nb, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb, Lu, Hf, and Ta) between rutile and three silicate melt compositions equilibrated at 1 atm pressure, 1300 °C and fO2 values from two log units below the quartz-fayalite-magnetite oxygen buffer (QFM-2) to air (QFM+6.5). Rutile/melt partition coefficients (DVrt/melt) change dynamically over an eight-log unit range of fO2 and are greatest at fO2 = QFM-2 in all compositions. Vanadium solubility in rutile declines continuously as fO2 increases from QFM-2 and approaches unity in air. Trace-element partitioning between rutile and melt is also correlated with melt composition, with the greatest values of Drt/melt measured in the most polymerized melt systems containing the least TiO2. We do not find any circumstances where V becomes incompatible in rutile. Our results indicate that rutile is a considerable sink for V at terrestrial fO2 values and will contribute to the retention of V in refractory slab residues in subduction zones. In agreement with previous work, we find that DTart/melt>DNbrt/melt under all conditions investigated, suggesting that rutile fractionation does not lead to low Nb/Ta ratios in Earth's continental crust.

Methylmercury and Trace Element Distribution in the Organs of Stenella coeruleoalba Dolphins Stranded on the French Mediterranean Coast

2014 ◽  
Vol 8 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Emmanuel Wafo ◽  
Véronique Risoul ◽  
Thérèse Schembri ◽  
Véronique Lagadec ◽  
Frank Dhermain ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Marine Pollution ◽  
Element Distribution ◽  
Mediterranean Coast ◽  
Trace Element Distribution ◽  
Slight Reduction ◽  
Stenella Coeruleoalba ◽  
Contamination Levels

The main objective of this study was to evaluate the contamination by mercury (Hg), methylmercury (Me-Hg), cadmium (Cd), selenium (Se), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in dolphins stranded on the French Mediterranean coast. The distributions of these contaminants in the organs of dolphins have also been studied. Overall, contamination levels varied according to the following sequence: liver > kidney > lung > muscle, except for cadmium (kidney > liver > lung > muscle). Size and sex of animals were also considered. Young dolphins were less impacted with trace elements than adults, except for copper. Among the studied parameters, the most important appeared to be the size of mammals. In addition, in the case of mercury and selenium, the sex of mammals seemed to be also relevant. The correlations between the concentrations of trace elements suggest the existence of detoxification processes. Since 1990s, using dolphins for tracing marine pollution, a slight reduction in the burden of the considered trace elements could be noted.

11. Trace-Element Partitioning Between Amphibole and Silicate Melt

Amphiboles ◽  
2007 ◽  
pp. 417-452 ◽  
Author(s):  
Massimo Tiepolo ◽  
Roberta Oberti ◽  
Alberto Zanetti ◽  
Riccardo Vannucci ◽  
Stephen F. Foley
Keyword(s):  
Trace Element ◽  
Silicate Melt ◽  
Trace Element Partitioning ◽  
Element Partitioning

Trace-Element Partitioning Between Amphibole and Silicate Melt

2007 ◽  
Vol 67 (1) ◽  
pp. 417-452 ◽  
Author(s):  
M. Tiepolo ◽  
R. Oberti ◽  
A. Zanetti ◽  
R. Vannucci ◽  
S. F. Foley
Keyword(s):  
Trace Element ◽  
Silicate Melt ◽  
Trace Element Partitioning ◽  
Element Partitioning

Trace-element distribution in a garnet-chlorite rock from Foel Ddu, near Harlech, Merionethshire

1956 ◽  
Vol 31 (235) ◽  
pp. 319-327 ◽  
Author(s):  
P. A. Mohr
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Analytical Data ◽  
Element Distribution ◽  
Trace Element Distribution

SummaryAnalytical data on a garnet-chlorite rock and the contained garnet with spectrographic determinations of the trace elements are presented, and the principles determining the distribution of these elements between the garnet and the chlorite are discussed.

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