Results on the afterglow of GRB 130603B suggest substantial, perhaps most, R-process nucleosynthesis occurs in NS mergers. A peak ~10 days after a short GRB in NIR was predicted by Barnes and Kasen (arXiv:1303.5787) and observed in the afterglow of the Swift GRB 130603B (Berger et al. arXiv:1306.3960, http://hubblesite.org/news/2013/29. The amount of R-process material synthesized in neutron star mergers is expected to be comparable with all of the existing material. If most of the R-process occurs in NS-NS mergers, as opposed to SN, how would this affect conclusions from the abundances in various samples of matter, including cosmic rays?

I would expect the cosmic-ray abundances are not very sensitive to the difference of the R-process in NS-NS mergers and in supernova, and in any case that difference may be slight in terms of elemental abundances (I have not heard of a calculation of the expected abundances from NS mergers). However, the GRB result has implications for the pre-acceleration age and mixing of GCR material, since NS-NS mergers are not typically expected to occur in SN-rich volumes, for example OB-association environments.

Article Constraints on the nucleosynthesis of refractory nuclides in...