Calcite oxygen isotope fractionation

Gilg HA, Taubald H, Struck U (2007) Phosphoric acid fractionation factors for aragonite between 25 and 72°C with implications on aragonite-calcite oxygen isotope fractionations. Geochim Cosmochim Acta 71 A323. 

Rosenbaum JM, Mattey DP (1995) Equilibrium gamet-calcite oxygen isotope fractionation. Geochim Cosmochim Acta 59 2839-2842... 

Clayton RN, Goldsmith JR, Mayeda TK (1989) Oxygen isotope fractionation in quartz, albite, anorthite, and calcite. Geochim Cosmochim Acta 53 725-733... 

For crystals with molecule-like constituents, like the BO, " and BO4 " groups in some borates, semi-quantitative models of the molecular component as a gas-phase entity have been proposed (Oi et al. 1989). This is conceptually similar to the approximation made for species in solution, although in practice most studies of crystals consider additional frequencies that reflect inter-molecular vibrations. The spectroscopic data on these vibrations (which typically have lower frequencies than the intra-molecular vibrations) are often available, at least approximately, from infrared and Raman spectroscopy and elastic properties. This type of hybrid molecule-in-crystal model has been applied to many minerals in theoretical studies of carbon and oxygen isotope fractionation, the most noteworthy being studies of calcite (Bottinga 1968 Chacko et al. 1991) and sihcates (Kieffer 1982). Because specfroscopic dafa are always incomplete (especially for subsfances substifufed wifh rare isolopes), some amounl of vibralional modeling is necessary. 

Figure 11,31 Oxygen isotopic fractionation between calcite and diopside as obtained from equations 11.131 to 11.133. Experimental data points are from Chiba et al. (1989). Dotted line indications from vibrational calculations following Kielfer s (1982) procedure. From Clayton and Kielfer (1991), reprinted with kind permission of The Geochemical Society, Pennsylvania State University, University Park, Pennsylvania.

Table 11.12 Oxygen isotope fractionation in quartz-mineral, mineral-water, and calcite-mineral couples, according to modified increment method of Zheng (1991, 1993a,b).

Chiba H., Chacko T., Clayton R. N., and Goldsmith J. R. (1989). Oxygen isotope fractionations involving diopside, forsterite, magnetite, and calcite Application to geothermometry. Geochim. Cosmochim. Acta, 53 2985-2995. 

Fig. 2.16 Oxygen isotope fractionations between various minerals and calcite (after Chacko et al, 2001)...

Leclerc AJ, Labeyrie LC (1987) Temperature dependence of oxygen isotopic fractionation between diatom silica and water. Earth Planet Sci Lett 84 69-74 Ldcuyer C, Grandjean P, Reynard B, Albarede F, Telouk P (2002) B/ °B analysis of geological materials by ICP-MS Plasma 54 application to bron fractionation between brachiopod calcite and seawater. Chem Geol 186 45-55... 

O Neil J.R. and Epstein S. (1966) Oxygen isotope fractionation in the system dolomite-calcite-carbon dioxide. Science 152, 198-201. 

Sediments were also extensively cemented by near-surface and pre-compactional eogenetic siderite (8 0 = -16.9%o to -8.1%o), calcite (5 0 = -10.2%o to -4.8%o) and dolomite (5 0 = -4.3%o to -1.5%o). The anomalously low5 0 values of siderite are attributed to microbial oxygen isotopic fractionation, as it would otherwise indicate unreasonably high precipitation temperatures (up to 120°C). The eogenetic caleites and dolomites precipitated from such meteoric waters at temperatures of 10-30°C. 

In summary, the cultured B. aculeata A8 C and A8 0 values are consistent with no microhabitat 8 C effect in culture, and a carbonate ion effect on shell isotopic composition. If the carbonate ion effect is similar to the planktic foraminifera effect (Spero et al. 1997), the most consistent results for both isotopes would be obtained using an equilibrium oxygen isotopic fractionation intermediate between the predictions of McCorkle et al. (1997) and Shackleton (1974). The isotopic offsets of the field specimens are consistent with a pore water 8 C influence on shell 8 C and no carbonate ion effect, and an equilibrium oxygen isotopic composition no higher than the McCorkle et al. (1997) prediction consideration of likely trends in pore water carbonate chemistry suggests an even lower equilibrium oxygen isotopic composition, similar to the prediction of Bemis et al. (1998). Thus these culture and fleld data, considered in the context of the carbonate chemistry of the culture and fleld systems, do not yield a consistent estimate of the equilibrium fractionation factor for 8 0 in benthic foraminiferal calcite. Further culture experiments, including carbonate chemistry manipulations, may help resolve this discrepancy. 

Figure 4. Temperature-dependence of oxygen or carbon isotope fractionation factors in some representative mineral-fluid and mineral-mineral systems as indicated by theoretical calculations. All curves are for oxygen isotope fractionations except for C02-calcite, which is for carbon isotope fractionations.

Figure 17. Plot of experimentally determined oxygen isotope fractionation factors between various metal carbonates and water at low temperatures. The carbonates were synAesized by precipitation from solution or replacement of calcite. Data sources CaCOs (calcite), SrCOs, and BaCOs - O Neil et al. (1969), corrected in Friedman and O Neil...

Chacko T, Mayeda TK, Clayton RN (1989) Oxygen isotope fractionations in the system gehlenite-calcite. EOS Trans Am Geophys Union 70 489... 

Clayton RN, Goldsmith JR, Karel KJ, Mayeda TK, Newton RC (1975) Limits on the effect of pressure on isotopic fractionation. Geochim Cosmochim Acta 39 1197-1201 Clayton RN, Goldsmith JR, Mayeda TK (1989) Oxygen isotope fractionation in quartz, albite, anorthite, and calcite. Geochim Cosmochim Acta 53 725-733... 

Figure 2. Experimentally determined oxygen isotope fractionations between calcite and quartz, albite, anorthite, diopside, forsterite and magnetite (Clayton and Kieffer 1991).

Fortier SM, Luttge A, Satir M, Metz P (1994) Oxygen isotope fractionation between fluorphlogopite and calcite An experimental investigation of temperatnre dependence and F70H effects. Enr J Mineral 6 53-65... 

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