Element partitioning

Elements present in only minor or trace concentrations are partitioned in quite different ways. These elements are not abundant enough to form their own minerals, so they must be incorporated into minerals composed of the major elements. Because they must fit into crystalline sites whose sizes and coordination are already fixed, the ease with which they can be included depends on ionic size and charge. Trace ions that fit nicely into sites otherwise occupied by major ions having similar sizes and charges are said to be compatible. Conversely, large ions with high charge, referred to as incompatible elements, tend to be excluded from most crystal sites. [Pg.212]

Element partitioning is expressed in terms of a distribution coefficient D, defined as [Pg.212]

Some trace elements actually are preferentially incorporated into certain sites in crystal [Pg.212]

Rare earth element patterns for basalt and chondrite, and the chondrite-normalized basalt REE pattern. Normalization removes the zigzag pattern due to differences in odd and even atomic number abundances. The europium (Eu) anomaly in the normalized pattern is due to incorporation of extra plagiodase. [Pg.213]

Metallic liquids can also experience fractional crystallization. The abundances of trace elements such as gold, gallium, germanium, and iridium and the major element nickel in various classes of iron meteorites vary because of the separation of crystalline metal phases (kamacite or taenite). [Pg.213]

This is the famous BPS equation it shows that k jj depends on R, but it does not show that it depends on orientation. [Pg.56]

Figure 3. Cartoon illustrating the lattice strain model of trace element partitioning. For an isovalent series of ions with charge n+ and radius entering crystal lattice site M, the partition coefficient,, can be...

Plagioclase has a single large cation site (M) into which all U-series elements partition. This site is normally occupied by Ca and Na, with coordination number increasing with increasing Na content. For simplicity we will assume VIII coordination... [Pg.103]

Spinels. There are limited experimental data on uranium and thorium partitioning between magnetite and melt (Nielsen et al. 1994 Blundy and Brooker 2003). Both studies find U and Th to be moderately incompatible. Blundy and Brooker s results for a hydrous dacitic melt at 1 GPa and 1025°C give Du and D h. of approximately 0.004. The accuracy of these values is compromised by the very low concentrations in the crystals and the lack of suitable SIMS secondary standards for these elements in oxide minerals. Nonetheless, these values are within the range of Djh of magnetites at atmospheric pressure 0.003-0.025 (Nielsen et al. 1994). It is difficult to place these values within the context of the lattice strain model, firstly because there are so few systematic experimental studies of trace element partitioning into oxides and secondly because of the compositional diversity of the spinels and their complex intersite cation ordering. [Pg.112]

Barth MG, Foley SF, Horn 1 (2002) Partial melting in Archean subduction zones constraints from experimentally determined trace element partition coefficients between eclogitic minerals and tonahtic melts under upper mantle conditions. Precamb Res 113 323-340... [Pg.119]

Blundy JD, Wood BJ, Davies A (1996) Thermodynamics of rare earth element partitioning between clinopyroxene and melt in the system Ca0-Mg0-Al203-Si02. Geochim Cosmochim Acta 60 359-364 Blundy JD, Robinson JAC, Wood BJ (1998) Heavy REE are compatible in clinopyroxene on the spinel Iherzolite solidus. Earth Planet Sci Lett 160 493-504... [Pg.120]

Blundy JD, Dalton JA (2000) Experimental comparison of trace element partitioning between clinopyroxene and melt in carbonate and silicate systems and implications for mantle metasomatism. Contrib Mineral Petrol 139 356-371... [Pg.120]

Blundy JD, Brooker RA (2003) Trace element partitioning during melting and ciystalhzation of mafic rocks in the lower crust. Contrib Mineral Petrol (submitted). [Pg.120]

Foley SF, Jackson SE, Fryer BJ, Greenough JD, Jenner GA (1996) Trace element partition coefficients for clinopyroxene and phlogopite in an alkaline lamprophyre from Newfoundland by LAM-ICP-MS. Geochim Cosmochim Acta 60 629-638... [Pg.121]

Forsythe LM, Nielsen RL, Fisk MR (1994) High-field-strength element partitioning between pyroxene and basaltic to dacitic magmas. Chem Geol 117 107-125... [Pg.121]

Green TH (1994) Experimental studies of trace element partitioning applicable to igneous petrogenesis-Sedona 16 years later. Chem Geol 117 1-36... [Pg.121]

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... [Pg.121]

Jones JH (1995) Experimental trace element partitioning. In Ahrens TJ (ed) Rock physics and phase relations A handbook of physical constants Am Geophys Union Reference Shelf 3 73-104 Kennedy AK, Lofgren GE, Wasserburg GJ (1993) An experimental study of trace element partitioning between olivine orthopyroxene and melt in chondrales equilibrium values and kinetic effects. Earth Planet Sci Lett 115 177-195... [Pg.122]

Law KM, Blnndy JD, Wood BJ, Ragnarsdottir KV (2000) Trace element partitioning between wollastonite and carbonate-silicate melt. Mineral Mag 64 155-165... [Pg.122]

McDade P, Blundy J, Wood B (2003b) Trace element partitioning on the Tinaquillo Lherzolite solidus at 1.5 GPa. Phys Planet Earth Int (snbmitted)... [Pg.122]

Mahood GA, Stimac JA (1990) Trace-element partitioning in pantellerites and trachytes. Geochim Cosmochim Acta 54 2257-2276... [Pg.123]

Nielsen RL, Beard JS (2000) Magnetite-melt HFSE partitioning. Chem Geol 164 21-34 Onuma N, Higuchi H, Wakita H, Nagasawa H (1968) Trace element partition between two pyroxenes and the host lava. Earth Planet Sci Lett 5 47-51... [Pg.123]

Salters VJM, Longhi J (1999) Trace element partitioning during the initial stages of melting beneath midocean ridges. Earth Planet Sci Lett 166 15-30... [Pg.123]

Schmidt KH, Bottazzi P, Vannucci R, Mengel K (1999) Trace element partitioning between phlogopite, clinopyroxene, and leucite lamproite melt. Earth Planet Sci Lett 168 287-299 Shaimon RD (1976) Revised effetive ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Cryst A32 751-767... [Pg.123]

Taura H, Yurimoto H, Kurita K, Sueno S (1998) Pressure dependence on partition coefficients for trace elements between olivine and the coexisting melts. Phys Chem Min 25 469-484 Taura H, Yurimoto H, Kato T, Sueno S (2001) Trace element partitioning between silicate perovskites and ultracalcic melt. Phys Planet Earth Int 124 25-32... [Pg.123]

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... [Pg.124]

Wood BJ, Blundy JD (2003) Trace element partitioning. In Treatise on Geochemistry. Carlson R (ed) Elsevier (in press)... [Pg.124]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...