Elemental and isotopic compositions

The composition of the Earth was determined both by the chemical composition of the solar nebula, from which the sun and planets formed, and by the nature of the physical processes that concentrated materials to form planets. The bulk elemental and isotopic composition of the nebula is believed, or usually assumed to be identical to that of the sun. The few exceptions to this include elements and isotopes such as lithium and deuterium that are destroyed in the bulk of the sun s interior by nuclear reactions. The composition of the sun as determined by optical spectroscopy is similar to the majority of stars in our galaxy, and accordingly the relative abundances of the elements in the sun are referred to as "cosmic abundances." Although the cosmic abundance pattern is commonly seen in other stars there are dramatic exceptions, such as stars composed of iron or solid nuclear matter, as in the case with neutron stars. The... 

The exact mass of an ion (4 to 6 decimal points) reliably defines its elemental and isotopic composition, while the method is called high resolution mass spectrometry. The measurements are conducted manually or automatically (computerized). Manual measurements are based on the parallel acquisition of the peak of interest with the closest peak of an ion with the known composition. Any compound with an intense ion peak with m/z value in the region +10% may serve as a marker. The most widespread markers are perfluorokerosene, perfluorotributylamine, and other polyfluorinated compounds. The use of these compounds is based on their volatility, as well as on the fact that fluorine is a monoisotopic element. In the spectra of these compounds intense ion peaks randomly cover all the range between m/z 19 and M+. ... 

Mozley PS, Carothers WW (1992) Elemental and isotopic compositions of siderite in the Kuparuk formation, Alaska effect of microbial activity and water/sediment interaction on early pore-water chemistry. J Sed Pet 62 681-692... 

Day, M. P., Zhang, B., and Martin, G. J. (1995). Determination of the geographical origin of wine using joint analysis of elemental and isotopic composition. II-Differentiation of the principal production zones in France for the 1990 vintage. ]. Sci. Food Agric. 67,113-123. 

Mafic Plio-Quatemary rocks in Italy show very variable trace element and isotopic compositions. Incompatible2 trace element abundances and ratios are best illustrated by mantle-normalised diagrams (spiderdiagrams), where concentrations of single elements in the rocks are divided by the abundances of the same elements in the mantle (Wood 1979). 

The strong regionality for major, trace element and isotopic compositions of Italian Plio-Quatemary volcanism allows subdivision into several com-positionally different magmatic provinces. For the purpose of this review, a magmatic province is defined as a relatively restricted zone within... 

Table 8.2. Selected major, trace element and isotopic compositions of Sicily volcanic rocks. Numbers in parentheses refer to data obtained on different, though compositionally similar samples as those analysed for the other elements. Source of data 1) Carter and Civetta (1977) 2) Cinque et al. (1988) 3) Calanchi et al. (1989) 4) Espcranga and Crisci (1995) 5) D Orazio et al. (1997) 6) Beccaluva et al. (1998) 7) Civetta et al. (1998) 8) Trua et al. (1998) 9) Trua et al. (2003) 10) Armienti et al. (2004) 11) Author s unpublished data. ...

Table III. Elemental and Isotopic Compositions of Starting Materials and Pyrolysates Generated During Artificial Maturation...

Is the elemental and isotopic composition of the solar nebula uniform . 03.1.2.2 The composition of the solar photosphere... 

Advanced analytical techniques have permitted the trace element and isotopic compositions of individual layers within rim sequences to be determined, and these have been highly informative. The reader is referred to Wark and Boynton (2001) for a thorough summary of virtually all of the known measurements of rim sequences. 

Bulk elemental and isotopic compositions of type B CAIs 423... 

Clear textural evidence for evaporation is surprisingly rare. In the case of most CAIs, for which evaporation has been suggested to modify elemental and isotopic compositions (Grossman et al., 2000), the CAI is believed to have been... 

Because of the numerous secondary effects that modify the whole-rock elemental and isotopic compositions, our discussion below will focus solely on mineral-separate analyses for the Rb-Sr, Sm-Nd, Lu-Hf, and U-Pb isotope systems. In comparison, the Re-Os system is much more robust to the effects of... 

Table 3 Major element, trace element, and isotopic compositions of continental flood basalts. 

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