Fig. 5: Compilations of the Ni isotopes data.
From: Active methanogenesis during the melting of Marinoan snowball Earth
a Boxplots showing the Ni isotopic compositions of different reservoirs29,30,31,42,43,67,68,69,70. The box showing the range for δ60Ni value between upper and lower quartiles. The vertical line inside the box represents the median value, while that outside the box represents the maximum and minimum value. The red and blue dash lines represent the upper continental crust (UCC) and modern seawater compositions, respectively28,66. b Boxplot showing the Ni isotopic fractionations in various geochemical processes29,38. The weathering process preferentially dissolves heavy Ni, and laboratory experiment shows preferential absorption of light Ni in ferrihydrite precipitation41. Plants and methanogens preferentially absorb light Ni (ref. 25).
