LiBeB, O and Fe Evolution: Refractory Element and Cosmic Ray Transport   Delays
  Employing a Monte-Carlo based evolutionary code, we show that the delay of Fe deposition relative to O, due to the incorporation of supernova ejecta refractories in high velocity grains, can account for the rise of [O/Fe] with decreasing [Fe/H]. The predicted behavior of refractory Mg, Si, Ca and Ti, and volatile S, namely that the refractories should not show the rise, but that the behavior of S should be similar to that of O, appears to be confirmed (Takeda et al. 2000, astro-ph/0007007). The delayed deposition of Be, due to cosmic ray transport in a relatively low density medium, leads to consistency of primary Be evolution as a function of both [Fe/H] and [O/H]. 
R. Ramaty, B. Kozlovsky, R. E. Lingenfelter