Abstract
Nitrogen isotopes in peridotitic diamonds from Fuxian, China, suggest that the upper mantle δ15N-value has been globally homogeneous since at least the Proterozoic (-5 to -8‰/ATM), with similar values for subcontinental and MORB mantle. In addition, Fuxian diamonds retain the memory of a primary nitrogen lower in δ15N (down to -25‰). For the first time δ15N-values in diamonds match those of enstatite chondrites, supporting a formation of the Earth from such meteorites and the idea of a heterogeneous accretion of the Earth's volatiles. Nitrogen concentrations in diamonds are believed to depend strongly on the rate of the diamond growth and not to be an indicator of C/N ratios of the fluids from which they grew.
Original language | English |
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Pages (from-to) | 175-179 |
Number of pages | 5 |
Journal | Terra Nova |
Volume | 9 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Dec 1997 |
Externally published | Yes |