Partitioning basalts

I mentioned that new computer codes - RAFSCATT 1 and RAF-SCATT 2 have been very recently formulated by Dr. Gary Jacobs and Mr. William Anderson of Rockwell Hanford s Basalt Waste Isolation Project. These codes relate required engineered barrier (i.e., waste packages and seals performance to draft NRC and EPA criteria). A key part of these codes is that they partition... 

Forsythe LM, Nielsen RL, Fisk MR (1994) High-field-strength element partitioning between pyroxene and basaltic to dacitic magmas. Chem Geol 117 107-125... 

Green TH, Blundy JD, Adam J, Yaxley GM (2000) SIMS determination of trace element partition coefficients between garnet clinopyroxene and hydrous basaltic liquids at 2-7.5 GPa and 1080-1200°C. Lithos 53 165-187... 

Hauri EH, Wagner TP, Grove TL (1994) Experimental and natural partitioning of Th U Pb and other trace elements between garnet clinopyroxene and basaltic melts. Chem Geol 117 149-166 Hazen RM, Finger LW (1979) Bulk Modulus-volume relationship for cation-anion polyhedra. J Geophys Res 84 6723-6728... 

Thomas JB, Bodnar RJ, Shimizu N, Sinha AK (2002) Determination of zircon/melt trace element partition coefficients from SIMS analysis of melt inclusions in zircon. Geochim Cosmochim Acta 66 2887-2901 Thompson GM, Malpas J (2000) Mineral/melt partition coefficients of oceanic alkali basalts determined on natural samples using laser ablation-inductively eouple plasma-mass spectrometry (LAM-ICP-MS). Mineral Mag 64 85-94... 

Over the past 10 years a great deal of effort has gone into constraining the values of the partition coefficients for U and Th between mantle minerals and basalt. Chapter 3 (Elundy and Wood 2003) reviews this work in more detail however, a basic review relevant to observations in MORE and modeling is given here. 

Brenan JM, Shaw HF, Phinney DL, Ryerson FJ, (1994) Rutile-aqueous fluid partitioning of Nb, Ta, Hf, Zr, U and Th implications for high field strength element depletions in island-arc basalts. Earth Planet Sci Lett 128 327-339... 

Lundstrom CC, Shaw H, Ryerson F, Phinney D, Gill J, Williams Q (1994) Compositional controls on on the partitioning of U, Th, Ba, Pb, Sr and Zr between clinopyroxene and haplobasaltic melts implications for uranium series disequilibria in basalts. Earth Planet Sci Lett 128 407-423 Lnndstrom CC (2003) Uranium-series disequilibria in mid-ocean ridge basalts observations and models of basalt genesis. Rev Mineral Geochem 52 175-214... 

Figure 1.11 Ni/MgO vs FeO/MgO relationship for the Bay of Island basalts and picrites (Table 1.12 data from Francis, 1985). The curve is a least-square parabolic fit through the data. Since D = MgoFe° remains constant, the DMg0Nl partition coefficient increases with increasing FeO/MgO [equation (1.5.10)].

Figure 4.11 Monte-Carlo simulation (100 trials) of error propagation for La/Yb fractionation in residual melts by clinopyroxene-garnet removal from a basaltic parent magma (see text for parameter description and distributions used). Top mineral-liquid partition coefficients for La and Yb. Bottom variations of the La/Yb ratio as a function of the fraction F of residual melt.

This form of the partition coefficient, analogous to that used for Fe-Mg fractionation between olivine and melt (see Chapter 1), is necessary only for the rare cases where trace substitution affects Cj and Cp substantially. A number of reviews (O Nions and Powell, 1977 Michard, 1989) describe the various sorts of partition coefficients expressed either in mass-fractions, atom fractions, or normalized to a major element and their respective merits. If the discussion is restricted to a narrow range of chemical compositions (e.g., basaltic systems, Irving, 1978, Irving and Frey, 1984), enough experimental information exists on trace-element partitioning to resort to the wonderfully simple equation (9.1.1). 

A basalt contains 150 ppm Ni, 100 ppm Sr, 3 ppm Yb, and 10 ppm Rb. Calculate the concentration of each element after removal of 20 percent of a cumulate containing 30 percent olivine, 20 percent clinopyroxene and 50 percent plagioclase in the residual liquid and in the average cumulate. Assume the partition coefficients given in Table 9.6. 

Irving, A. J. Frey, F. A. (1984). Trace-element abundances in megacrysts and their host basalts Constraints on partition coefficients and megacryst genesis. Geochim. Cosmochim. Acta, 48, 1201-21. 

Ulmer, P. (1989). The dependence of the Fe2+-Mg cation-partitioning between olivine and basaltic liquid on pressure, temperature and composition An experimental study to 30kbars. Contrib. Mineral. Petrol., 101, 261-73. 

Ripley EM, Brophy JG, Li C (2002) Copper solubility in a basaltic melt and sulfide liq-uid/silicate melt partition coefficients of Cu and Fe. Geochim Cosmochim Acta 66 2791-2800 Rosman KJR (1972) A survey of the isotopic and elemental abundances of zinc. Geochim Cosmochim Acta 36 801-819. 

Harrison W. J. (1981). Partition coefficients for REE between garnets and liquids Implications of non-Henry s law behavior for models of basalt origin and evolution. Geochim. Cosmochim. Acta, 45 1529-1544. 

McCallum I. S. and Charette M. P. (1978). Zr and Nb partition coefficients Implications for the genesis of mare basalts, KREEP and sea floor basalts. Geochim. Cosmochim. Acta, 42 859-870. 

Philpotts A. R. (1979). Silicate immiscibility in tholeiitic basalts. J. Petrol, 20 99-118. Philpotts I A. and Schnetzler C. C. (1970). Phenocryst-matrix partition coefficients for K, Rb,... 

Consider Ca in a basaltic melt inclusion concentric with the host mineral olivine. The radius of the inclusion is SOfim. The olivine radius is 1 mm. The Ca partition... 

A. Kouchi, A. Tsuchiyama, and I. Sunagawa, Effect of stirring on crystallization kinetics of basalt texture and element partitioning, Contrib. Mineral. Petrol, 93,1986,429-38... 

Depending on the provenance of the olivine, the relative proportion of the sulfur species is different (Fig. 7 c). But the presence of sulfite SIV in addition to sulfate is demonstrated in oxidized and water rich basaltic magmas. The sulfite SIV may act as an intermediate metastable species, which results in partitionning of sulfur into the volcanic gaz emissions. 

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