Figure 7: Results of oxygen isotope analyses of small samples.
From: Tracing the oxygen isotope composition of the upper Earth’s atmosphere using cosmic spherules
Plot of Δ'17O of NBS-28 quartz (solid blue circles) and magnetite (solid red squares) versus amount of O2 (in moles) in the samples. The continuous flow measurements were normalized to NBS-28 with Δ'17O=−0.054‰. The smallest magnetite samples had masses of only ∼10 μg. No systematic variation in Δ'17O is observed with sample size. Errors are 1σ standard deviations.
