Figure 3.

Temporal evolution of carbon isotope ratios of the sufficiently abundant alkanes over the course of the hydrogen-rich experiments (solid squares) and the hydrogen-poor experiments (open squares). These ratios are presented as Δ¹³C, which is the difference between the measured δ¹³C of a given compound at a given time and the δ¹³C of the initial CH₄ for each run (eq 2). Error bars are the standard deviation for the experiments averaged into each time point.