Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds

Details Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds

Jul 1987

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987natur.328..139l&link_type=abstract

Nature, Volume 328, Issue 6126, pp. 139-141 (1987).

Physics

17

Scientific paper

To determine the amounts of cosmic-ray produced ('cosmogenic') 3He which could be created in diamonds during their post-eruptive residence in near-surface regions, we have measured the concentration of 10Be (half life, 1.6 Myr) in an industrial diamond sample. The motivation to study cosmogenic 3He in diamonds comes from the recent observations1,2 of 3He/4He ratios in some diamonds that are even higher than meteoritic values (so-called 'planetary' helium with 3He/4He = 1.4×10-4). We measured 10Be in an alluvial diamond sample, using radiochemical and accelerator mass spectrometry (AMS) techniques. The observed 10Be concentration, 2.46 +/- 0.39×106 atoms g-1, leads to an effective surface exposure of 3.3×105 yr for these diamonds. This corresponds to a substantial cosmogenic production of 3He in the alluvial diamonds, >==29% of the total 3He. We conclude that the high 3He/4He ratios in at least some diamonds are due to cosmogenic 3He production in near-surface regions during their residence in alluvial or weathering deposits. Thus, in order to establish that such high 3He/4He ratios existed in the mantle at one time, it is a priori necessary to study diamonds collected by underground mining methods.

Affiliated with

Also associated with

No associations

Rating

Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds 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 Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmogenic 10Be in Zaire alluvial diamonds: implications for 3He contents of diamonds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-791684