Table 2. Geochemistry Data.

Sampling Date	11 Aug 2011	24 Aug 2011
T (°C)	52.1	50.4
pH	8.6	8.7
Eh (mV)	−46	−133
TDS (ppt)	0.20	0.20
Cells ml−1	280a	200b

Gases (M)		Cations (M)		Carbon Sources (M)		Metals (M)
He	6.07 × 10−4	Na+	2.5 × 10−3	DOC	1.83 × 10−5	Total Fe	1.4 × 10−7
H2	1.71 × 10−5	K+	3.5 × 10−5	DIC	5.70 × 10−4	Fe2+ (Chemet)	<8.9 × 10−7
O2	1.52 × 10−4	Mg2+	4.1 × 10−5	DIC-Gas Solubility	3.56 × 10−3	Fe3+ (Chemet)	2.7 × 10−6
O2 (Chemet)	6.25 × 10−6	Ca2+	2.7 × 10−4	Formate	8.00 × 10−6	Mn	1.3 × 10−7
N2	5.98 × 10−3	Sr2+	3.2 × 10−6	Acetate	3.39 × 10−7	Cr	3.9 × 10−8
CO	9.1 × 10−5	Ba2+	5.7 × 10−7	Lactate	<1.10 × 10−6	Co	3.4 × 10−8
CO2	1.71 × 10−5	Al3+	2.2 × 10−6	Propanoate	<1.40 × 10−6	Ni	1.2 × 10−6
CH4	8.75 × 10−3	Si4+	4.8 × 10−4
C2H6	1.40 × 10−4
C3H8	2.05 × 10−5
i-C4H10	1.75 × 10−6
n-C4H10	3.00 × 10−5
i-C5H12	1.76 × 10−6
n-C5H12	<1.48 × 10−6
Non-Methane Hydrocarbons	4.44 × 10−4
Anions (M)		Sulfur Species (M)		Nitrogen Species (M)
F−	1.0 × 10−4	SO42−	1.04 × 10−4	Total N	3.21 × 10−6
Cl−	2.8 × 10−3	S2O32−	3.09 × 10−6	NO2−	<2.2 × 10−6
Br−	5.6 × 10−6	HS−	7.48 × 10−8	NO3−	9.52 × 10−7
PO43−	3.5 × 10−7			NH4+	3.88 × 10−6

^aBased upon cell counts using DAPI (Simkus et al., 2015).

^bBased on the bacterial biomass calculated from 46 599 l of filter H₂O resulting in 41.2 μg of PLFA (0.9 pg/ml) (Simkus et al., 2015).