Lithium isotope

Ooi, K., Miyai, Y., Makita, Y, and Kanoh, H., Fractionation of lithium isotopes in ion exchange chromatography with titanium phosphate exchanger, Separation Sci. Technol., 34, 1133, 1999. 

The classical method for lithium isotope separation employed chemical exchange between lithium amalgam and an aqueous solution of lithium hydroxide. 

Tomascak PB (2004) Developments in the understanding and application of lithium isotopes in the earth and planetary sciences. Rev Mineral Geochem 55 153-195... 

Yamaji K, Makita Y, Watanabe H, Sonoda A, Kanoh H, Hirotsu T, Ooi K (2001) Theoretical estimation of lithium isotopic reduced partition function ratio for lithium ions in aqueous solution. J Phys Chem A105 602-613... 

Developments in the Understanding and Application of Lithium Isotopes in the Earth and Planetary Sciences... 

Figure 1. Summary of lithium isotopic compositions of Earth and planetary materials. Filled bars are solid samples, open bars are liquids. See text for references and details.

BACKGROUND LITHIUM ISOTOPES IN THE SCIENCES Experiments in Li isotope fractionation... 

Figure 2. Lithium isotope separation effected during ion exchange with synthetic zeolite (Taylor and Urey 1938). As has been demonstrated repeatedly since that study, in both natural and synthetic experiments, Li is fixed more effectively in the exchanger than Li.

LITHIUM ISOTOPIC ANALYSIS From early Li isotope measurement to the modem era of analysis... 

Figure 3. Lithium isotope data for a range of commercially-available synthetic concentration standards (Qi et al. 1997a). The inset expands the c. 60%o range of reported natural samples. Although most anthropogenically-processed Li retains a broadly terrestrial value, nearly 20% of the samples examined show enormous isotopic enrichment in the heavy isotope.

The mantle, although Li-poor relative to the continents (5-6 ppm in normal MORE and c. 1 ppm in depleted peridotites Ryan and Langmuir 1987 Eggins et al. 1998), is a significant reservoir due to its large volume (discussed below under, Significance of lithium isotopes in the bulk Earth ). 

Figure 10. Lithium isotopic compositions of minerals from the Tin Mountain pegmatite. Black Hills, South Dakota (Tomascak et al. 1999c). Differences in the equilihrium quartz-feldspar oxygen isotopic compositions between the wall zone and intermediate zones suggested temperatures of 600 to 550°C (Walker et al. 1986). Despite poor precision of these data, they showed a consistent increase in the A Li, ,. between the early-crystallizing wall zone and the later-crystallizing core.

Lithium isotope studies of sediments and sedimentary rocks have thus far concentrated on marine clastic and carbonate material. No systematic description of the effects of diagenetic processes on sediments has been made. Clay rich sediments are important to Li budgets in near-surface systems, as they concentrate Li relative to marine carbonates, which are among... 

Lithium isotope data from carbonate shells of other marine invertebrates have been reported. Hoefs and Sywall (1997) determined isotopic compositions of seven different species of modem bivalves from the North Sea coast. These samples had a relatively small range in 5 Li (+15 to +21), which corresponds well to the seawater-carbonate offset from inorganic calcite and modem corals (Marriott et al. 2004). 

Figure 20. Lithium isotopic compositions of chondritic meteorites relative to their petrologic type (James and Palmer 2000a McDonough et al. 2003). The extant data indicate lighter and more variable isotopic compositions in higher petrologic types of meteorites, those with the least record of hydrous parent body alteration.

Benton LD, Tera F (2000) Lithium isotope systematics of the Marianas revisited. J Conf Abst 5 210 Benton LD, Savov 1, Ryan JG (1999) Recycling of subducted lithium in forearcs Insights from a serpentine seamount. EOS Trans, Am Geophys Union 80 S349... 

Bouman C, Vroon PZ, Elliott TR, Schwieters JB, Hamester M (2002) Determination of lithium isotope compositions by MC-ICPMS (Thermo Finnigan MAT Neptune). Geochim Cosmochim Acta 66 A97 Bray AM (2001) The geochemistry of boron and lithium in mid-ocean ridge hydrothermal vent fluids. PhD thesis. University of New Hampshire, 125 p... 

Chan LH, Edmond JM (1988) Variation of lithium isotope composition in the marine environment A preliminary report. Geochim Cosmochim Acta 52 1711-1717 Chan LH, Kastner M (2000) Lithium isotopic compositions of pore fluids and sediments in the Costa Rica subduction zone implications for fluid processes and sediment contribution to the arc volcanoes. Earlh Planet Sci Lett 183 275-290... 

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