Big Chemical Encyclopedia

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

Articles Figures Tables About

Calcium isotopes fractionation

Figure 9. (a) Box model of Skulan and DePaolo (1999) used to explain the 6 Ca variations found in the hone and soft tissue of vertehrates. The 6 Ca values of bone and soft tissue are generally determined by the ratios of the dietary Ca flux (V ), to the Ca fluxes due to bone formation (Pi,), and bone dissolution or loss (Vi). It is hypothesized that only the step associated with bone grovrth involves isotopic fractionation (lOOOlna = = -1.5). (b) Calculated effects on calcium isotopic fractionation due to variations of the... [Pg.272]

Gussone N, Eisenhauer A, Heuser A, Dietzel M, Bock B, Bohm E, Spero H, Lea D, Buma J, Nagler, TF (2003) Model for kinetic effects on calcium isotope fractionation (6 Ca) in inorganic aragonite and cultured planktonic foraminifera. Geochim Cosmochim Acta 67 1375-1382 Halicz L, Galy A, Belshaw NS, O Nions RK (1999) High precision measurement of calcium isotopes in carbonates and related materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). J Anal Atom Spectr 14 1835-1838... [Pg.286]

Russell WA, Papanastassiou DA (1978a) Calcium isotope fractionation in ion-exchange chromatography. Anal Chem 50 1151-1153... [Pg.287]

Skulan J, DePaolo DJ, Owens TL (1997) Biological control of calcium isotopic abundances in the global calcium cycle. Geochim Cosmochim Acta 61 2505-2510 Skulan J, DePaolo DJ (1999) Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates. Proc Nat Acad Sci 96 13,709-13,713... [Pg.287]

Gruber N, et al. (1999) Spatiotemporal patterns of carbon-13 in the global surface oceans and the oceanic Suess effect. Global Biogeochem Cycles 13 307-335 Gussone N, et al. (2005) Calcium isotope fractionation in calcite and aragonite. Geochim Cosmochim Acta 69 4485 494... [Pg.246]

Lemarchand D, Wasserburg GJ, Papanastassiou DA (2004) Rate-controUed calcium isotope fractionation in synthetic calcite, Geochim Cosmochim Acta 68 4665 678 Leng MJ, Marshall JD (2004) Palaeoclimate interpretation of stable isotope data from lake sediment archives. Q Sci Rev 23 811-831... [Pg.256]

Siebert C, McManus J, Bice A, Poulson R, Berelson WM (2006b) Molybdenum isotope signatures in continental margin sediments. Earth Planet Sci Lett 241 723-733 Sime NG, De la Rocha C, Galy A (2005) Negligible temperature dependence of calcium isotope fractionation in 12 species of planktonic foraminifera. Earth Planet Sci Lett 232 51-66 Simon K (2001) Does 5D from fluid inclusions in quartz reflect the original hydrothermal fluid Chem Geol 177 483 95... [Pg.271]

Steuber T, Buhl D (2006) Calcium-isotope fractionation in selected modern and ancient marine carbonates. Geochim Cosmochim Acta 70 5507-5521 Stevens CM (1988) Atmospheric methane. Chem Geol 71 11-21... [Pg.272]

Zhu and MacDougall (1998) showed that calcium isotope composition of the shells was both species and temperamre dependent and that river water is depleted by 2%o relative to seawater. The temperature dependency of calcium isotope fractionation enables this tracer to be a potential paleotem-peramre proxy (Nagler et al., 2000). The seawater Cal" Ca secular variations are indicated by the results of De La Rocha and De Paolo (2000) for the last 160 Myr, and by the data of Zhu (1999) for the entire 3.4 Gyr of earth history. The latter indicate that, in analogy to strontium isotopes (Veizer and Compston, 1976), the Archean samples have C Ca ratios similar to the earth mantle, with the crustal-like values first appearing at the Archean/Proterozoic transition. However, in contrast to the strontium isotope trend, the calcium isotope ratios appear to dip towards mantle values also at —1.6 Gyr ago. [Pg.3857]

Gussone, N., Eisenhauer, a., Heuser, a., Dietzel, M., Bock, B., Bohm, F., Spero, H. 1., Lea, D. W., Bijma, 1. Nagler, T. F. 2003. Model for kinetic effects on calcium isotope fractionation (8 Ca) in inorganic aragonite and cultured planktonic foramini-fera. Geochimica et Cosmochimica Acta, 67, 1375-1382. [Pg.44]

Teichert, B.M.A., Gussone, N., and Torres, M.E. (2009) Controls on calcium isotope fractionation in sedimentary porewaters. Earth Planet. Sci. Lett., 279, 373-382. [Pg.371]

Emrich, K., Emhalt, D.H. and Vogel, J.C. 1970 Carbon isotope fractionation during the precipitation of calcium carbonate. Earth and Planetary Science Letters 8 363-371. [Pg.112]

Hart, S. R. Zindler, A. (1989). Isotope fractionation laws A test using calcium. Int. J. Mass Spectr. Ion Proc., 89, 287-301. [Pg.530]

Sverjensky DA, Shock EL, Helgeson HC (1997) Prediction of flie thermodynamic properties of aqueous metal complexes to 1000°C and 5 kb. Geochim Cosmochim Acta 61 1359-1412 Tarutani T, Clayton RN, Mayeda TK (1969) The effect of polymorphism and magnesium substitution on oxygen isotope fractionation between calcium carbonate and water. Geochim Cosmochim Acta 33 987-996... [Pg.24]

Hamelin B, Manhes G, Albarede F, Allegre CJ (1985) Precise lead isotope measurements by the double spike technique a reconsideration. Geochim Cosmochim Acta 49 173-182 Hart SR, Zindler A (1989) Isotope fractionation laws A test using calcium. Int J Mass Spectr Ion Proc 89 287-301... [Pg.148]

Richter EM, Davis AM, Ebel DS, Hashimoto A (2002) Elemental and isotopic fractionation of type B calcium-aluminum-rich inclusions Experiments, theoretical considerations, and constraints on their thermal evolution. Geochim Cosmochim Acta 66(3) 521-540... [Pg.230]

Figure 1. Schematic representation of the calcium mass spectrum in (a) natural materials, (b) a Ca- Ca tracer solution used for separating natural mass dependent isotopic fractionation from mass discrimination caused by thermal ionization, and (c) a typical mixture of natiwal calcium and tocer calcium used for analysis. The tracer solution has roughly equal amounts of Ca and Ca. In (c) the relative isotopic abundances are shown with an expanded scale. Note that in the mixed sample, masses 42 and 48 are predominantly from the tracer solution, and masses 40 and 44 are almost entirely from natural calcium. This situation enables the instrumental fractionation to be gauged from the Ca/ Ca ratio, and the natural fractionation to be gauged from the sample Ca/ Ca ratio. Figure 1. Schematic representation of the calcium mass spectrum in (a) natural materials, (b) a Ca- Ca tracer solution used for separating natural mass dependent isotopic fractionation from mass discrimination caused by thermal ionization, and (c) a typical mixture of natiwal calcium and tocer calcium used for analysis. The tracer solution has roughly equal amounts of Ca and Ca. In (c) the relative isotopic abundances are shown with an expanded scale. Note that in the mixed sample, masses 42 and 48 are predominantly from the tracer solution, and masses 40 and 44 are almost entirely from natural calcium. This situation enables the instrumental fractionation to be gauged from the Ca/ Ca ratio, and the natural fractionation to be gauged from the sample Ca/ Ca ratio.
STUDIES OF TERRESTRIAL CALCIUM STABLE ISOTOPE FRACTIONATION... [Pg.267]

In an effort to further elucidate the nature of Ca isotope fractionation in animals, Skulan and DePaolo (1999) studied tissues from living and recently deceased (naturally) organisms. For the four animals studied, it was found that bone calcium typically has 5 Ca that is 1.3%o lower than the value in the dietary calcium (Fig. 8). The soft tissue calcium, however, is quite variable, and has values closer to that of the dietary calcium. Skulan and DePaolo (1999) concluded that the primary source of Ca isotope fractionation was in the formation of bone, and that the 5 Ca values of soft tissue were variable in time and dependent on the immediate status of the Ca balance in the organisms. [Pg.270]

The calcium carbonate shells of marine microfauna are a large repository of terrestrial calcium and constitute a potential record of changes in the cycling of calcium at and near the earth s surface (Zhu and MacDougall 1998 De La Rocha and DePaolo 2000 Schmitt et al. 2003a,b). To understand the record held in deep sea carbonate sediments, it is necessary to document any Ca isotopic fractionation that occurs between dissolved seawater Ca and carbonate shell material. [Pg.271]

Ireland TR, Fahey AJ, Zinner EK (1991) Hibonite-bearing microspherules a new type of refractory inclusions with large isotopic anomalies. Geochim Cosmochim Acta 55 367-379 Johnson CM, Beard BL (1999) Correction of instrumentally produced mass fractionation during isotopic analysis of Fe by thermal ionization mass spectrometry. Int J Mass Spect 193 87-99 Jungck MHA, Shimamura T, Lugmair GW (1984) Calcium isotope variations in Allende. Geochim Cosmochim Acta 48 2651-2658... [Pg.286]

Platzner I, Degani N (1990) Fractionation of stable calcium isotopes in tissues of date palm trees. Biomed Environ Mass Spect 19 822-824... [Pg.287]

Richter FM, Davis AM, Ehel DS, Hashimoto A (2002) Elemental and isotopic fractionation of Type B calcium-, aluminum-rich inclusions Experiments, theoretical considerations, and constraints on their thermal evolution. Geochim Cosmochim Acta 66 521-540 Richter FM, Davis AM, DePaolo DJ, Watson EB (2003) Isotope fractionation by chemical diffusion between molten basalt and rhyolite. Geochim Cosmochim Acta 67 3905-3923 Rudnick RL, Fountain DM (1995) Nature and composition of the continental crust—a lower crustal perspective. Rev Geophys 33 267-309... [Pg.287]

Ca = 0.000031, and Ca = 0.001824. The high relative abundance of °Ca (a result of its mass number A, which is a multiple of 4 and thus exceptionally stable cf section 11.3) is one of the two main problems encountered in this sort of dating (in Ca-rich samples, the relative enrichment in °Ca resulting from °K decay is low with respect to bulk abundance). The other problem is isotopic fractionation of calcium during petrogenesis (and also during analysis see for this purpose Russell et al., 1978). These two problems prevent extensive application of the K-Ca method, which requires extreme analytical precision. The isochron equation involves normalization to the Ca abundance... [Pg.756]

De La Rocha C (2003) Sihcon isotope fractionation by marine sponges and the reconstruction of the silicon isotope composition of ancient deep water. Geology 31 423 26 De La Rocha CL, De Paolo DJ (2000) Isotopic evidence for variations in the marine calcium cycle over the Cenozoic. Science 289 1176-1178... [Pg.239]

EmUiani C (1966) Paleotemperature analysis of Caribbean core P6304-8 and P6304-9 and a generalized temperature curve for the past 425000 years. J Geol 74 109-126 Emiich K, Ehhalt DH, Vogel JC (1970) Carbon isotope fractionation during the precipitation of calcium carbonate. Earth Planet Sci Lett 8 363-371 Engel MH, Macko SA, SUfer JA (1990) Carbon isotope composition of individual amino acids in the Murchison meteorite. Nature 348 47-49... [Pg.241]

Gussone N, et al. (2006) Cellular calcium pathways and isotope fractionation in Emiliania huxleyi. Geology 34 625-628... [Pg.246]

See other pages where Calcium isotopes fractionation is mentioned: [Pg.229]    [Pg.255]    [Pg.255]    [Pg.784]    [Pg.461]    [Pg.229]    [Pg.255]    [Pg.255]    [Pg.784]    [Pg.461]    [Pg.241]    [Pg.74]    [Pg.90]    [Pg.1049]    [Pg.445]    [Pg.255]    [Pg.262]    [Pg.267]    [Pg.270]    [Pg.771]    [Pg.246]    [Pg.259]    [Pg.273]   
See also in sourсe #XX -- [ Pg.330 ]



SEARCH



Calcium isotopic

Fractionation isotope

Isotope isotopic fractionation

Isotopic fractionation

© 2024 chempedia.info