Compositional controls on the partitioning of U, Th, Ba, Pb, Sr and Zr between clinopyroxene and haplobasaltic melts: implications for uranium series disequilibria in basalts

The effect of sodium and titanium on crystal-melt partitioning of trace elements

“…We would suggest that the difference between the trace element partitioning behavior of the two sets of clinopyroxenes is due to the relatively low Ca-Tschermaks content in those of Blundy and Dalton (2000). Lundstrom et al (1994) also found that both the increased solubility of jadeite and tetrahedral aluminium at higher pressures (Blundy et al, 1995) are important factors in determining trace element behavior in silicate systems, particularly for the highly charged cations Th, U and Zr. Lundstrom et al, (1994) also suggest that coupled substitutions involving Na or Al charge balance the high valence actinides, allowing greater solubility of these elements at high pressure, through the formation of components such as ThMgAl 2 O 6 and NaZrAlSiO 6 .…”

Understanding melt generation beneath the slow-spreading Kolbeinsey Ridge using 238U, 230Th, and 231Pa excesses

“…wehr et al, 2001)), fractionation is mainly controlled by clinopyroxene with D Th > D U , creating small 238 U excesses in the melt (La Tourette and Burnett, 1992;La Tourette et al, 1993;Beattie, 1993a,b;Hauri et al, 1994;Lundstrom et al, 1994;Salters and Longhi, 1999;Wood et al, 1999;Landwehr et al, 2001;Salters et al, 2002;Elkins et al, 2008).…”

An experimental study of the grain-scale processes of peridotite melting: implications for major and trace element distribution during equilibrium and disequilibrium melting

“…As shown in Fig. 9, the apparent partition coefficients are correlated with the Al IV content of the residual cpx, as has been observed in a number of partitioning studies (e.g., Hart and Dunn, 1993;Hauri et al, 1994;Lundstrom et al, 1994;Gaetani and Grove, 1995;Blundy et al, 1998;Hill et al, 2000;Gaetani, 2004). This point will be further discussed in Section 5.2 below.…”

“…It is well known that cpx-basaltic melt partition coefficients for REE and HFSE depend strongly on the abundance of tetrahedrally coordinated Al (Al IV ) in cpx, whereas cpx-melt partition coefficient for Sr is insensitive to the Al IV abundance in cpx (e.g., McKay, 1986;Hart and Dunn, 1993;Hauri et al, 1994;Lundstrom et al, 1994;Gaetani and Grove, 1995;Blundy et al, 1998;Hill et al, 2000;Gaetani, 2004). Figure 9 shows the cpx-melt partition coefficients for REE, Y, Ti, Zr, and Sr as a function of Al IV abundance in cpx reported in recent laboratory partitioning studies (references given in the caption to Fig.…”

“…Lundstrom et al, 1994;Gaetani and Grove, 1995;Hill et al, 2000). Measuring REE and selected incompatible trace element abundance in interstitial melt and reprecipitated cpx of variable Al 2 O 3 abundance in our reaction couples will allow us to identify the dominant mass transfer processes governing the distribution and partitioning of the high charge, slow diffusing cations during partial melting and melt-rock reaction.…”