. 2016 Jul 21;6:29883. doi: 10.1038/srep29883

Table 2. Measured physical parameters and concentrations of species relevant to this discussion in various marine HT vents and modern bulk seawater. ^aRefs ⁴³,⁴⁵; ^bRefs ⁸⁴, ⁸⁵, ⁸⁶; ^cRef. ⁸⁷, ^dRefs ³⁹,⁸⁸, ^eRef. ⁵⁹, ^fRef. ⁴⁵, −.= not determined, bd = below detection limit as reported.

	Rainbow^a,c,d	9°50′ East Pacific Rise^a,b,d	Guaymas Basin^a,e	Lost City^a,d,f	Seawater ^a,b,c,d
Temperature (°C)	365	221–363	172–299	94	2
pH	3	3.5–4.2	4.48–6.09	10.2	8.1
H₂ (mM)	12–16	0.4–1.2	0.5–3.3	9.1–10.5	—
CO₂ (mM)	20–24	8.19–99.3	35–51	<0.19	2.36
CO (μM)	5.1–7.3	<2	0–92	<1	—
CH₄ (mM)	2	<0.11	44–59	<1.09	—
Formate (μM)	—	—	—	<140	bd
Acetate (μM)	—	—	65–365*	1–35	bd
H₂S (mM)	2–3.3	4.6–19.2	6.8–8	0.07–0.47	—
CH₃SH (nM)	7.7–10.3	4–11.4	8.1–16,700	1.4–1.9	—
SO₄²⁻ (mM)	0	0	0	1–4	53

*The acetate detected in Guaymas Basin fluids is attributed to contributions from microbes and thermal cracking of biological material in sediments.

Table 2. Measured physical parameters and concentrations of species relevant to this discussion in various marine HT vents and modern bulk seawater. aRefs 43,45; bRefs 84, 85, 86; cRef. 87, dRefs 39,88, eRef. 59, fRef. 45, −.= not determined, bd = below detection limit as reported.