Normalization to chondrite

Figure 2. Rare earth elements concentrations (normalized to chondrites) for the original rocks (serpentinite and hornblende diorite) and their alteration products...

Chondritic relative abundances of strongly incompatible RLEs (lanthanum, niobium, tantalum, uranium, thorium) and their ratios to compatible RLEs in the Earth s mantle are more difficult to test. The smooth and complementary patterns of REEs in the continental crust and the residual depleted mantle are consistent with a bulk REE pattern that is flat, i.e., unfractionated when normalized to chondritic abundances. As mentioned earlier, the isotopic compositions of neodymium and hafnium are consistent with chondritic Sm/Nd and Lu/Hf ratios for bulk Earth. Most authors, however, assume that RLEs occur in chondritic relative abundances in the Earth s mantle. However, the uncertainties of RLE ratios in Cl-meteorites do exceed 10% in some cases (see Table 4) and the uncertainties of the corresponding ratios in the Earth are in same range (Jochum et ai, 1989 W eyer et ai, 2002). Minor differences (even in the percent range) in RLE ratios between the Earth and chondritic meteorites cannot be excluded, with the apparent exception of Sm/Nd and Lu/Hf ratios (Blicher-Toft and Albarede, 1997). 

Figure 8 End-member REE concentrations in vent fluids from four different black smokers at tbe 21° N vent site, EPR, normalized to chondrite (REE data from Klinkhammer et ah, 1994). NGS = National Geographic Smoker, HG = Hanging Gardens, OBS = Ocean Bottom Seismometer, SW = South West vent.

Fig. 3. Isotope-dilution REE analyses (normalized to chondrite) of oxide-facies iron-rich cherts (TR40, 41,...

Figure 4.21 Rare earth element abundances in North American Shale Composite (NASC) and European shale, normalized to chondritic values. Data from Table 4.7, columns 5 and 6 nonnalizing values from Table 4.5, column 4.

Figure 4,29 Transition metal concentrations in MORE (from Langmuir et aL, 1977) normalized to chondritic values. The normalizing values are taken from Langmuir et ai. (1977) with the. . . exception of Fe, which was taken from Wood et al. (1979b) — Table 4.12.

Fig. 2. The plot of total reduced iron, Fe, and oxidized iron, Fe, normalized to Si abundance shows how the chondrite classes fall into groups distinguished by oxidation state and total Fe Si ratio. The soHd diagonal lines delineate compositions having constant total Fe Si ratios of 0.6 and 0.8. The fractionation of total Fe Si is likely the result of the relative efficiencies of accumulation of metal and siUcate materials into the meteorite parent bodies. The variation in oxidation state is the result of conditions in the solar nebula when the soHds last reacted with gas. Terms are defined in Table 1 (3).

Fig. 2.34. (A) Chondrite-normalized REE pattern of fresh basaltic andesite. (B) Chondrite-normalized REE pattern of altered basaltic andesite. (C) Ratios of REE content in the altered rock normalized to the fresh basaltic andesite (298-R-02). The dashed line is the ratio line of one. (D) Chondrite-normalized REE patterns of hydrothermal fluids from Vienna Wood, Pacmanus and Desmos, Tamagawa and Kusatsu-Yubatake (Gena et al., 2001).

Figure 9.9 REE abundances from archaeological glass, showing the effect of chondrite normalization, (a) shows the raw abundances of the REE measured on a set of English medieval window glasses, with the saw-tooth pattern evident, and little indication of differences between any of the samples (apart from perhaps one which has lower overall REE concentrations), (b) shows the same data normalized to the chondrite data (Table 9.1). The saw-tooth has largely disappeared, and close inspection suggests that two samples have a positive europium anomaly, possibly indicating a different geographical origin.

In the cosmochemistry literature, you will often see data normalized to (that is, divided by) solar system abundances (most commonly those of Cl chondrites). An important reason for doing this is illustrated in Figure 4.6. The top panel of this figure shows a plot of the composition of a chondrule with the elements arranged in order of their volatility from most... 

Almost immediately after the discovery of presolar grains, it was clear that they could only be found in the most primitive chondrites, those that had suffered the least amount of thermal metamorphism. Further work showed that the abundances of presolar grains, when normalized to the content of fine-grained matrix where the grains reside, correlated strongly... 

Elemental abundances in CR2 chondrites normalized to the Cl composition and plotted in order of decreasing volatility from left to right. Lithophile elements are shown with open circles, siderophile elements with black circles, and chalcophile elements with gray circles. CR2 data from Kallemeyn etal. (1994). 

Volatile element abundances in CV chondrites (normalized to Cl chondrites and silicon) lie along a linear array on semi-log plots versus their 50% condensation temperatures. This depletion pattern persists, whether the elements are siderophile, lithophile, or chalcophile. 

Bulk compositions of H, L, and LL chondrites normalized to Cl abundances. Elements are plotted in order of decreasing volatility from left to right. Lithophile, siderophile, and chalcophile elements are designated with open, black, and gray symbols, respectively. These diagrams reveal fractionation of these element groups among different ordinary chondrite classes. Data from Kallemeyn et al. (1989). 

Concentrations of metallic iron and oxidized iron, normalized to silicon, indicate that both oxidation/reduction and loss of metal are required to explain the compositions of various chondrite classes. 

Noble gas abundances in lunar soils and chondrites, (a) Elemental abundance patterns for trapped solar wind in lunar soils, normalized to solar system abundances, (b) Elemental abundance patterns for planetary trapped noble gases, normalized to solar system abundances. This diagram is intended to illustrate patterns only vertical positions are arbitrary. Modified from Ozima and Podosek (2002). 

As we learned earlier in Chapters 4 and 7, chondritic abundances can vary. Figures 11.9a and 11.9c show variations in lithophile elements, and Figures 11.9b and 11.9d illustrate variations in siderophile and chalcophile elements (all normalized to Cl chondrite abundances, and plotted in order of increasing volatility from left to right in each diagram) for the major classes of anhydrous meteorites. As is apparent in these... 

Compositional variations among chondrites, (a) Lithophile and (b) siderophile and chalcophile elements in ordinary (H, L, LL), enstatite (EH, EL), R, and chondrites. In (c) and (d), the same data are shown for anhydrous carbonaceous chondrite groups. Elements are plotted from left to right in order of increasing volatility. Lithophile elements are normalized to Cl chondrites and Mg, siderophile and chalcophile elements are normalized to Cl chondrites. Modified from Krot et al. (2003). 

Elemental abundances, normalized to Mg and Cl chondrites, for two groups of primitive achondrites (acapulcoites and winonaites) that experienced low degrees of partial melting. These abundances are similar to chondritic abundances (average H-chondrite composition is illustrated). Modified from Mittlefehldt (2004). 

Figure 12.17a shows lithophile element abundances, and Figure 12.17b shows sid-erophile and chalcophile element abundances in CM chondrites, normalized to Cl chondrites. Illustrated for comparison are the abundances in CO chondrites, which are the anhydrous carbonaceous chondrite group most closely allied to CM chondrites. As in other chondrites, the greatest differences are in volatile elements. The volatile and moderately volatile elements in CM chondrites are present at 50-60% of the abundances of the refractory elements. The volatile elements are primarily located in the matrix, and the matrix comprises 50-60% of CM chondrites. This implies that the matrix has essentially Cl abundances of all elements, while the chondrules and refractory inclusions have Cl relative abundances of refractory elements but are highly depleted in the volatile elements. The sloping transition in the region of moderately volatile elements indicates... 

Differences in the abundances of (a) lithophile and (b) siderophile and chalcophile elements, all normalized to cosmic (Cl chondrite) abundances, among altered carbonaceous chondrite groups. Normalizations as in Fig. 11.9. Modified from Krot etal. (2004). 

Comparison of the abundances of volatile and refractory elements, normalized to Cl chondrites, for the Moon and the Earth. After Taylor et al. (2006a). 

Estimated compositions ofthe giant planets are given in Table 14.3, normalized to the solar composition. The relative proportions of rock and volatiles are estimated from mean densities, the rock compositions are assumed to be chondritic, and the ratios of hydrogen to helium are derived from spectroscopic or spacecraft measurements of atmosphere compositions. 

Figure 7.6 Isotopic compositions of meteorite (Murray), solar, and terrestrial Xe, displayed as per mil variation of observed isotope ratios (normalized to 130Xe) in air and the carbonaceous chondrite Murray from the corresponding ratios SUCOR, a solar Xe composition calculated to be surface-correlated Xe in a lunar mare soil. The dashed line, illustrating linear fractionation, is primarily for reference. Reproduced from Podosek (1978).

Table 10.1 Elemental abundances for several objects in the Solar System, normalized to Si and Cl chondrites. Following Halliday et al. 2001, Fodders 2003. Siderophile elements are indicated by. ...

Fig. 3a. (Upper diagram). Abundances of chemical elements in lunar rock 12018 vs. the abundances in carbonaceous chondrites type 1 (C 1) normalized to silicon. Data for 12018 were taken from all authors of the Second Lunar Science Conference. Geochim. Cosmochim. Acta, Supplement 2,2 (1971), data for C 1 from the compilation of Mason17 ...

Wanke et al.13) have proposed a model in which the Moon is composed of a mixture of HTC and a material equivalent in elemental composition to bronzite (H = high-iron group) chondrites, but with a different degree of oxidation. Evidence in favor of ordinary chondrites as the component containing the low-temperature elements is presented in Fig. 17. Normalized to potassium, the ratios of the alkali metal elements in the lunar soil samples 12070 are plotted relative to the C 1 chondrites as well as relative to the H-group chondrite Forest City. We have previously seen that K, Rb, and Cs are correlated with one an-... 

REE are normalized to their concentration in chondritic meteorites. Fe concentration has been calculated as % Fe203. Other elements are reported as ppm (weight basis). 

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