Is that what you're presenting at the Astrobiology Conference next week? If so, you're presenting right before me, looking forward to it!

Thanks Joanne! The N concentrations are based on a prebiotic Earth - otherwise biomass would elevate them. We don’t have a precise age, just early Archean, pre-life. If we can reach a decision on when exactly life originated on earth, we could narrow down that window a bit!