Component primordial

Note that this situation for Ne is unlike that for " °Ar, in which primordial Ar is negligible. Because the measured Ne is comprised of 3 components (primordial, atmospheric and nucleogenic), the calculation of Ne requires deconvolution using Ne/%CE, Ne/ Nes, fii and Ncm-... 

With the advent of 8- to 10-metre class telescopes in the 1990s, it became possible to approach the primordial deuterium problem more directly, by measuring the isotopic component in absorption lines of hydrogen due to intervening gas along... 

Fig. 4.12. Stellar lithium abundances (log of the number per 1012 H atoms) among main-sequence stars as a function of metallicity. The full-drawn curve shows the prediction of a numerical Galactic chemical evolution model, while the broken-line curve gives the sum of a primordial component and an additional component proportional to iron and normalized to meteoritic abundance. Adapted from Matteucci, D Antona and Timmes (1995).

As is true today, most phosphate in the primordial crust must have been sequestered in nearly insoluble calcium phosphates and carbonates or in basalts, and only dissolved monomeric phosphate was produced by weathering. [201] However, the volatile polyphosphate P4O10 is known to be a component of volcanic gases. [205] This material originates from the polymerization of phosphate minerals in mag-... 

Figure 11.23 shows the isochron obtained by Marshall and De Paolo (1982) for the granite batholith of Pikes Peak (Colorado). The effectiveness of the double-spike technique is evident, especially when we see that aliquot-spiked samples do not fall on the best-fit interpolant (York s algorithm York, 1969). The obtained age (1041 32 Ma) is consistent with that previously obtained with Rb-Sr whole rock analyses (1008 13 Ma see Marshall and De Paolo, 1982, for references). The initial ratio ( Ca/ Ca)o of 151.0 is identical, within the range of uncertainty, to upper mantle values, indicating negligible contamination by old crust components the relative K/Ca abundance in the earth s mantle is about 0.01, a value too low to alter the primordial (" Ca/" Ca)o composition. 

Extraterrestrial materials consist of samples from the Moon, Mars, and a variety of smaller bodies such as asteroids and comets. These planetary samples have been used to deduce the evolution of our solar system. A major difference between extraterrestrial and terrestrial materials is the existence of primordial isotopic heterogeneities in the early solar system. These heterogeneities are not observed on the Earth or on the Moon, because they have become obliterated during high-temperature processes over geologic time. In primitive meteorites, however, components that acquired their isotopic compositions through interaction with constituents of the solar nebula have remained unchanged since that time. 

Star formation and the formation of star systems with planets around them, constantly takes place in dense interstellar clouds. The material present in these clouds is incorporated into the objects that are formed during this process. Pristine or slightly altered organic matter from the cloud from which our solar-system was formed is therefore present in the most primitive objects in the solar system comets, asteroids, and outer solar-system satellites. Pieces of asteroids (and perhaps comets) can be investigated with regards to these components through the analyses of meteorites (and eventually in samples returned from these bodies by spacecraft) in laboratories on Earth. The infall of asteroid and comet material from space may have contributed to the inventory of organic compounds on primordial Earth. 

REE patterns are fractionated for all the rocks, but tholeiites show lower La/Yb ratios than alkaline products (Fig. 8.5a). Incompatible element patterns normalised to primordial mantle compositions for mafic rocks are very different from the Aeolian arc and central-southern Italian peninsula. Both tholeiitic and alkaline basalts show a marked upward convexity, with negative spikes of K (Fig. 8.5b). Note, however, that there are also negative anomalies for Hf and Ti, which are uncommon in most Na-alkaline basalts from intraplate settings (e.g. Wilson 1989). Overall, the Etna magmas have been found to be more enriched in volatile components than common intraplate magmas, and water contents up to 3-4 wt % have been found by melt inclusion studies (Corsaro and Pompilio 2004 Pompilio, personal communication). 

If we imagine history running back in time, we inevitably come to the epoch of the "big squeeze" with all the galaxies, stars, atoms and atomic nuclei squeezed, so to speak, to a pulp. During that early stage of evolution, matter must have been dissociated into its elementary components.. .. We call this primordial mixture ylem. 

To resolve the primordial terrestrial noble gas, it would be useful to examine major noble gas reservoirs in the early solar system, which could have supplied noble gases to the Earth. As we discussed in Chapter 3, two major noble gas components occur very widely in the solar system and can be a potential source for the terrestrial noble gas. They are solar noble gas (representative of the sun), which is generally assumed to be best represented by solar wind noble gas implanted on Al-foil target plates on the moon (elemental ratio) and on lunar breccia (isotopic ratio) (e.g., Ozima et al., 1998), and Q phase noble gas (see Wieler, 1994, for a review), which occurs very widely in various chondrites. Next we will compare the bulk Earth noble gas, which we assume to be represented by atmospheric noble gas with these two major noble gas components in the solar system. 

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