Table 1

Elements, detector crystals, count times, and primary standards used in EPMA analysis

ElementDetector crystalPeak count time (s)Background time (s)Primary standard (Smithsonian catalog number)
Spinel analysis
SiTAP3015San Carlos olivine (NMNH 111312 44)
TiPETJ4020Kakanui hornblende (NMNH 143965)
AlTAP4020Spinela (NMNH 136804)
CrLiFH3015Tiebaghi Mine chromite (NMNH 117075)
FeLiFH3015San Carlos olivine
MnLiF3015Manganitea (NMNH 157972)
MgTAP3015San Carlos olivine
CaPETJ3015Wollastonitea (synthetic, F.R. Boyd, no catalog no.)
NaTAP3015Kakanui hornblende
NiLiF4020San Carlos olivine
Olivine and orthopyroxene analysis
SiTAP2010Olivine (S.C. olivine, orthopyroxene); Johnstown Meteorite hypersthene (USNM 746)
TiPETJ2010Kakanui hornblende
CrLiFH2010Tiebaghi Mine chromite
FeLiFH2010San Carlos olivine
MgTAP2010San Carlos olivine
NaTAP2010Roberts Victor Mine omphacite (NMNH 110607)
KPETJ2010Asbestos microclineb (NMNH 143966)
NiLiF2010San Carlos olivine
  • Notes: All standards from Jarosewich et al. (1980), except as noted below.

  • a Smithsonian internal reference standard (compositions given in Supplementary1 Table S5).

  • b Smith and Ribbe (1966).