Noble gas partition

There are no noble gas partitioning data for amphiboles. Given the multiplicity of cation and anion sites in this mineral it seems likely that Uru will be higher than in other silicate minerals. 

There are no noble gas partition coefficients for phlogopite. The large size and low mean charge of the large X-site (Zg )) suggest that noble gases could be readily incorporated into phlogopite. 

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). 

Matsuda et al. (1993) studied noble gas partition between iron melt and silicate melt at 1550°C for pressures ranging from 5 to lOOkbar. Noble gas partition coefficients thus determined showed a systematic decrease with increasing pressure (Figure 2.7), from about 5 x 10 2 at 5kbar to about 5 x 10 4 at lOOkbar. The results may... 

Matsuda, I, Sudo, M., Ozima, M., Ito, K., Ohtaka, O., Ito, E. (1993) Noble gas partitioning between metal and silicate under high pressures. Science, 259, 788-90. 

Shibata, T., Takahashi, E., Ozima, M. (1994) Noble gas partition between basaltic melt and olivine crystals at high pressure. In Noble Gas Geochemistry and Cosmochemistry, J. Matsuda, Ed., pp. 343-54. Tokyo Terra Scientific Publishing Co. 

Abundance patterns. The measured noble gas abundance patterns of MORE and OIB scatter greatly. This is due to alteration as well as fractionation during noble gas partitioning between basaltic melts and a vapor phase that may be then preferentially gained or lost by the sample. However, MO Ne/Ar and Xe/Ar ratios that are greater than the air values are common (Table 2). This pattern was found in a gas-rich MORE... 

The core remains a possible source of isotopically distinctive He. However, further work is required, especially on noble gas partition coefficients into core material, both to support this and to formulate the evolution of other noble gases within the mantle. 

Sudo M, Ohtaka O, Matsuda J-I (1994) Noble gas partitioning between metal and silicate under high pressures the case of iron and peridotite. In Noble gas geochemistiy and cosmochemistry. Matsuda J-I (ed) Terra Scientific Publishing Co., Tokyo, p 355-372 Suess HE (1949) The abundance of noble gases in the Earth and the cosmos. J Geol 57 600-607 (in German)... 

Noble gas partitioning and solubility fractionation between equilibrated subsurface phases was initially studied by Goryunov and Kozlov (1940) and further studied (Zartman et al. 1961 Bosch and Mazor 1988 Zaikowski and Spangler 1990 Ballentine et al. 1991 Ballentine et al. 1996 Hiyagon and Kennedy 1992 Pinti and Marty 1995 Torgersen and Kennedy 1999 Battani et al. 2000). Recent reviews are by O Nions and Ballentine (1993), Ballentine and O Nions (1994) and Pinti and Marty (2000). 

Noble gas partitioning between a seawater-derived groundwater and the oil phase at the average Magnus Sandstone aquifer temperature requires a subsurface seawater/oil volume ratio of 110( 40) to account for both the °Ne and Ar concentrations in the central and southern Magnus samples. 

Early planetary differentiation included separation of Fe-Ni from mantle silicates to form the core. While a considerable fraction of some elements partitioned into coreforming material at this time, it is not known to what extent significant amounts of noble gases were transferred to the core in this way. The basic data for noble gas partitioning between silicates and metal at high temperatures and pressures is still scarce (see Porcelli and Ballentine 2002, this volume). 

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