The evolution of galactic beryllium and boron traced by magnesium and calcium

Beryllium and boron abundances are consistently derived on the parameter scale of two recent uniform stellar Mg and Ca abundance studies, one utilizing non-LTE parameters and abundances, the other assuming LTE. The results are used to explore the BeB-Mg and BeB-Ca relations at low metallicity as urged by B.D. Fields and coworkers. The slopes of all logarithmic BeB-MgCa relations, regardless of light element (Be or B), metallicity tracer (Mg or Ca), or parameter scale (non-LTE or LTE), are found to lie in the range 1.1-1.3. These results using the alpha-elements Mg and Ca confirm the need for a metal-poor "primary" BeB production mechanism (perhaps in addition to standard Galactic cosmic rays) previously inferred from BeB-Fe and questioned BeB-O relations.