Partition coefficient basalt

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... 

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. 

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. 

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 He in a fluid inclusion in olivine in a basaltic melt. The radius of the inclusion is 50 fim. The olivine radius is 1 mm. The He partition coefficient between olivine and melt is estimated to be 0.0001. Assume that He diffusivity in olivine is 10 m /s. Find the reequilibration timescale. 

Hiyagon and Ozima (1986) employed a laboratory approach of measuring crystal-melt partition coefficients. They measured noble gas concentration in olivine crystals and basalt melts, which were synthesized at 1370-1300°C under an atmospheric pressure, and also at 1360-1050°C under high pressure (0.2-1.5 GPa), of noble gas mixture. From these experimental results, they obtained ranges for noble gas partition coefficients XHe = 0.07, XNe = 0.006-0.08, KM = 0.05-0.15, KXe = 0.3. These partition coefficients are much larger than the values obtained by Marty and Lussiez (1993) and also these of common incompatible elements such as U (-0.002) or K (0.0002 - 0.008) between olivine and basalt melt (e.g. Henderson, 1982). 

Table 2.4. Crystal/matrix partition coefficients of noble gases in basaltic melts...

Hiyagon, H. (1994a) Constraints on rare gas partition coefficients from analysis of olivine-glass from a picritic mid-ocean ridge basalt - Comments. Chem. Geol., 112, 119-27. 

Dale and Henderson (1972) investigated trace element distribution in phenocrysts (olivine, pyroxene) and basalt matrix, with much consideration of crystal field effects. Banno and Matsui (1973) published a new formulation of partition coefficients for trace element distribution between minerals and magmas, based on the concept of chemical potentials for liquids and crystals. 

Philpotts, J. A., Schnetzler, C. C. Phenocryst-matrix partition coefficients forK, Rb, Sr and Ba with application to anorthosite and basalt genesis. Geochim. et Cosmochim. 

McKay G., Le L., and Wagstaff J. (1991) Constraints on the origin of the mare basalt europium anomaly REE partition coefficients for pigeonite. In Lunar Planet. Sci. XXII. The Lunar and Planetary Institute, Houston, (CD-ROM), pp. 883-884. 

These relationships lead to the simple consequence that the variability of element concentrations in large data sets of basalt analyses are related to the bulk partition coefficients of these elements (Hofmann, 1988 Dupre et al., 1994). This can be verified by considering a set of trace... 

Noting that magnesium is partitioned into both sites in orthopyroxene, the M2-melt partition coefficient D g for basaltic liquids is —1.0. Adopting this value implies, for the larger alkaline earth cations. 

Nicholls I. A. and Harris K. L. (1980) Experimental rare earth element partition coefficients for garnet, clinopyroxene and amphibole coexisting with andesitic and basaltic liquids. Geochim. Cosmochim. Acta 34, 331-340. 

Figure 6 Effect of silicate melt composition on metal/silicate partition coefficients for cobalt ( ), gallium (+), tungsten (o), and phosphorus ( ) (Jaeger and Drake, 2000 Pak and Fruehan, 1986). NBO/t is calculated according to Mysen (1991) and corresponds to basalt values of 1, komatiite —1.7, and peridotite —2.8. In general, high-valence elements such as tungsten and phosphorus are affected more strongly than lower valence elements such as cobalt (or nickel).

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