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An inter-laboratory comparison of cosmogenic ^3He and radiogenic ^4He in the CRONUS-P pyroxene standard
| Content Provider | Semantic Scholar |
|---|---|
| Author | Blard, Pierre-Henri Balco, Greg Burnard, Pete Farley, Kenneth A. Fenton, Cassandra R. Friedrich, R. Jull, A. J. Timothy Niedermann, Samuel Pik, Raphaël Schaefer, J. M. Scott, Edward M. Shuster, David L. Stuart, Finlay M. Stute, Martin Tibari, Bouchaib Winckler, Gisela Zimmermann, Laurent |
| Copyright Year | 2015 |
| Abstract | This study reports an inter-laboratory comparison of the 3He and 4He concentrations measured in the pyroxene material CRONUS-P. This forms part of the CRONUS-Earth and CRONUS-EU programs, which also produced a series of natural reference materials for in situ produced ^(26)Al, ^(10)Be, ^(14)C, ^(21)Ne and ^(36)Cl. Six laboratories (GFZ Potsdam, Caltech Pasadena, CRPG Nancy, SUERC Glasgow, BGC Berkeley, Lamont New York) participated in this intercomparison experiment, analyzing between 5 and 22 aliquots each. Intra-laboratory results yield ^3He concentrations that are consistent with the reported analytical uncertainties, which suggests that ^3He is homogeneous within CRONUS-P. The inter-laboratory dataset (66 determinations from the 6 different labs) is characterized by a global weighted mean of (5.02 ± 0.12) × 10^9 at g^(−1) with an overdispersion of 5.6% (2σ). ^4He is characterized by a larger variability than ^3He, and by an inter-lab global weighted mean of (3.60 ± 0.18) × 10^(13) at g^(−1) (2σ) with an overdispersion of 10.4% (2σ). There are, however, some systematic differences between the six laboratories. More precisely, 2 laboratories obtained mean ^3He concentrations that are about 6% higher than the clustered other 4 laboratories. This systematic bias is larger than the analytical uncertainty and not related to the CRONUS-P material (see Schaefer et al., 2015). Reasons for these inter-laboratory offsets are difficult to identify but are discussed below. To improve the precision of cosmogenic ^3He dating, we suggest that future studies presenting cosmogenic 3He results also report the ^3He concentration measured in the CRONUS-P material in the lab(s) used in a given study. |
| Starting Page | 11 |
| Ending Page | 19 |
| Page Count | 9 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.quageo.2014.08.004 |
| Volume Number | 26 |
| Alternate Webpage(s) | http://noblegas.berkeley.edu/~noblegas/files/Blard%20(2015)%20Intercomparison%20Helium.pdf |
| Alternate Webpage(s) | https://doi.org/10.1016/j.quageo.2014.08.004 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
