The mantle-normalized patterns of AUK are also characterized by near chondritic
Ti/Zr (~110) and depletion of Th, Nb and LREE (Fig.
Whole-rock isotopic data from the Riga, Marjamaa, Naissaare, Neeme, and Abja plutons indicate an approximately chondritic
source for Nd in the mafic rocks of the Riga batholith and the Abja intrusion, and a Palaeoproterozoic (Svecofennian) protolith for the felsic rocks--the [T.
Plots of the analyses, normalized to chondritic
values (Anders and Ebihara, 1982) are shown in Figure 9 and Figure 10.
While it is generally assumed that the global bulk composition of Earth and other terrestrial planets is chondritic
for refractory elements such as Sm and Nd, it has recently been shown that the 142Nd/144Nd values display a systematic and reproducible bias between all the chondrites and the average composition of the Earth, and also possibly of other planets.
One of the most profound mysteries of modern planetary science is this: As the terrestrial planets are more-or-less of common chondritic
composition, how does one account for the marked differences in their surface dynamics?
Identification of REE fractionation in the metacarbonate rocks was carried out by normalising (Haskin et al, 1968) the concentration of the rare earth elements to average chondritic
meteorites, and the result for samples having concentrations beyond detection limits is presented as REE pattern (Figure 7).
2010) demonstrated the presence of non-reworked extraterrestrial L-type chondritic
chromite grains in the breccia, which gives further support to an impact origin.
Four syenitic samples and one metarhyolite sample show similar chondrite-normalized patterns, with light REE enrichment (200 to 400 times chondritic
values) and gently sloping heavy REE at 20 to 40 times chondritic
values, and lie in the field defined by felsic samples from the West Barneys River suite (Fig.
Adding a tiny amount of chondritic
material could explain where many present-day metals came from," says Matthias Willbold, a geochemist at the University of Bristol in England, whose team reports the findings in the Sept.