~9- Self-absorption corrections for B and spikes. made for counting were 5 per cent citrate dried on 1$-inch plates and in some instances for 0.5 per cent oxalate plated and flamed on These correction factors are as the same size planchets. follows: Oxalate samples Isotope Correction factor Anton Fe-9s ar ??-Nb9> Rut6p,106 Methane gas-flow 8.3 1.54 15.4 5.6 1.54 1.54 *Fe-> was counted only in the methare gas-flow chamber. A total correction factor of 4 was used (based on 50 per cent geometry and an assumed counting efficiency of 50 per cent). Citrate samples Isotope Correction factor Anton Methane gas-flow Fe? - 4i.g 0°? 11.6 2.8 gr9°9° 4.7 1.9 tr? cp? 18.8 C097 +58, 60 y Rutgy} 13.1 5.4 - 3.2 3,2 2.0 3.2 6.0 2.2 cs'3? 6.2 2,2 cel tt p14 6.5 2.2 yp It. cea