Fig. 2: Correlation between CAP/(Ca + Mg) (mmol/mol) and δ¹³Ccarb in the global dataset.
From: Marine phosphorus and atmospheric oxygen were coupled during the Great Oxidation Event
a All data. b After removing outliers defined as values beyond 1.5× the interquartile range. Points are coloured by metamorphic facies: green = unmetamorphosed; dark orange = prehnite–pumpellyite red = greenschist. Solid lines are least-squares fits for each facies. a: unmetamorphosed R = +0.4, p < 0.01 prehnite–pumpellyite R = +0.5, p < 0.01; greenschist R = +0.23, p < 0.01. b: unmetamorphosed R = +0.61 p < 0.01 prehnite–pumpellyite R = +0.34, p < 0.01; greenschist R = +0.51, p < 0.01 Overall, higher δ¹³Ccarb values tend to coincide with higher CAP values.
