ORNL Synopsis: Analysis of a Metallic Specimen

Synopsis: Analysis of a Metallic Specimen6
-400 400
-200 200
-200 200
0
0-200-400 400200
0 0
δ26Mg (‰)
δ25Mg (‰)
UP TO 1.5 X 106
UP TO 5.0 X 105
UP TO 1,000
UP TO 750
Graphite LD - Super Nova
Graphite HD - low metal AGB
Group 3 - low mass, low metallicity
Group 1 - low to intermediate mass Red Giant or AGB star
Group 2 - low/very low-mass AGB star
Group 4 - Super Nova
UP TO 1400
UP TO 5.0 X 105
Earth Brazilian specimen
NASA JSC metal
Meteorites Seawater
Manufactured metal
DOW metal
Aerospace metal
Sample A
-2 0-7-12-17-22
-12
-10
-8
-6
-4
-8
0
2
4
δ26Mg (‰)
δ25Mg (‰)
Kinetic Fractionation
Equilibrium fractionation
Figure 6: Artistic representation including the magnesium isotope systematics of the unknown material, specifically shown
relative to other terrestrial, non-terrestrial, and extrasolar materials. The figures plot the δ26Mg′ vs. the δ25Mg′, which represent
the differences in 26Mg/24Mg and 25Mg/24Mg isotopes relative to a known standard (DSM-3) in parts per thousand (‰)
notation. This calculation adjusts for known instrumental mass bias effects inherent in ICP-MS analyses and is consistent
with how magnesium data in literature are often presented. (Top) The extreme magnesium isotope compositions possible
from different star types. (Bottom) A zoomed-in view of the magnesium isotope compositions of local solar system
materials and the material in question. Uncertainty envelopes are not included, but when plotted with their uncertainties,
data points overlap the kinetic and equilibrium fractionation lines. (Note: Data points shown with a diamond shape, included
for completeness, were extracted from an older analysis source; we cannot directly verify the precision or correctness of
these data. The delta values were calculated relative to DSM-3, and a systematic offset correction factor was applied; error
bars for these points reach ± 2 ‰ uncertainty.)