Physics
Scientific paper
Sep 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003pepi..139...35k&link_type=abstract
Physics of the Earth and Planetary Interiors, Volume 139, Issue 1-2, p. 35-43.
Physics
5
Scientific paper
The spatial distribution of carbon and nitrogen isotopes in diamonds provides information on mantle residence time. Diamonds with long residence at high temperature will gradually lose their initial zoning patterns due to diffusion. Using experimentally determined carbon self-diffusion coefficients and nitrogen diffusion coefficients derived from aggregation experiments, we have modeled the diffusive relaxation of zoning profiles with a spectrum of wavelengths. Carbon isotope heterogeneity will be preserved on wavelengths greater than ~1μm after 1 billion years' residence at 1400K, and on wavelengths greater than ~200μm after 1 million years' residence at 2000K. Nitrogen isotope zoning is relaxed much more slowly, with 0.1μm zoning preserved over the age of the Earth at 1400K and 1μm zoning preserved after 1 million years at 2000K. The large difference in diffusive relaxation times between carbon and nitrogen isotopes means that initially correlated carbon and nitrogen profiles will lose their correlation after sufficient diffusion of carbon has taken place. This could be used as a thermochronometer. Carbon isotope heterogeneity in diamonds associated with lower mantle mineral assemblages has significantly smaller amplitude than nitrogen isotope heterogeneity, consistent with diffusive relaxation at high temperatures in the lower mantle.
Koga Kenneth T.
van Orman James A.
Walter Michael J.
No associations
LandOfFree
Diffusive relaxation of carbon and nitrogen isotope heterogeneity in diamond: a new thermochronometer does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Diffusive relaxation of carbon and nitrogen isotope heterogeneity in diamond: a new thermochronometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diffusive relaxation of carbon and nitrogen isotope heterogeneity in diamond: a new thermochronometer will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1088751