Table 2 O₂ consumption and DIC and TA production during sequential aerobic respiration, sulfate reduction and carbonate mineral dissolution in bottom waters^{45, 83}

Redox	Δ[O₂] ( μmol kg⁻¹)	ΔDIC ( μmol kg⁻¹)	ΔTA ( μmol kg⁻¹)	ΔTA/ΔDIC	pH	Ω_arag
AR	(CH₂O)₁₀₆(NH₃)₁₆(H₃PO₄) + 106O₂ ↔ 106CO₂ + 16HNO₃ + H₃PO₄ + 122H₂O			−(16+1)/106 = −0.16
	0 (100%)	0	0		8.055	1.56
	−58 (75%)	+45	−7.2		7.859	1.05
	−117(50%)	+90	−14.4		7.629	0.65
	−174(25%)	+134	−21.5		7.421	0.40
	−231.7(0%)	+178.0	−28.5		7.237	0.26
SR	(CH₂O)₁₀₆(NH₃)₁₆(H₃PO₄) + 53SO₄ ²⁻ → 106HCO₃ ⁻ + 53H₂S + 16NH₃ + H₃PO₄			(106+16−1)/106 = 1.142
	0	+70.0	+80.6		7.199	0.25
CD	CaCO₃ + CO₂ + H₂O → Ca²⁺ + 2HCO₃ ⁻			2/1
	0	+57.6	+115.3		7.368	0.38
Total	−231.7	+305.6	+167.3

AR, aerobic respiration; CD, carbonate dissolution; DIC, dissolved inorganic carbon; SR, sulfate reduction; TA, total alkalinity. The last columns listed the expected pH and aragonite mineral saturation state (Ω_arag) values at the end of each step. pH and Ω_arag values are also calculated at the initial and mid-points of O₂ consumption (or % of O₂ saturation). For simultaneous reactions at low pH and Ω_arag, see the text. The calculation steps and results are detailed in the Methods. Note for a more stable carbonate mineral, calcite, Ω_calcite = 1.5 × Ω_arag

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