Table 1. Hydrogeochemical characteristics of the drill hole sections investigated with DGGE (•), pyrotag sequencing (○) and shotgun metagenomic sequencing (○) in this study.

		200 m •○	600 m •○	900 m•	1000 m•○	1100 m•○	1300 m•○	1500 m•○	1700 m•	1900 m•○	2100 m•	2300 m•○
Sample depth	m	150–250	550–650	850–950	950–1000	1050–1150	1250–1350	1450–1550	1650–1750	1850–1950	2050–2150	2250–2350
Main rock types		Mica schist, biotite gneiss	Mica schist, biotite gneiss	Biotite gneiss, mica schist	Biotite gneiss, mica schist	Biotite gneiss, mica schist	Black schist, mica schist, skarn, serpentinite	Serpentinite, skarn, black schist	Biotite gneis, mica schist	Pegmatitic granite, mica schist, biotite gneiss	Pegmatitic granite	Pegmatitic granite, mica schist
Pressure	bar	20	60	90	100	110	130	150	170	190	210	230
Hydraulic conductivity	km s−1	n.d.	n.d.	n.d.	5.3 × 10−7	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
Permeability	km2	n.d.	n.d.	n.d.	4.8 × 10−14	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
Ca:Na		0.80	0.83	0.81	0.81	0.87	1.36	1.65	1.68	1.67	1.65	2.31
Br:Cl		0.0026	0.0027	0.0029	0.0028	0.0026	0.0029	0.0034	0.0028	0.0030	0.0025	0.0024
Temperature	oC	7.75	12.91	16.	18.14	19.48	22.22	24.56	27.55	30.67	32.31	37.07
pH		9.7	7.2	8.3	7.9	7.3	8.2	8.2	8.5	8.4	8.2	8.9
Ca	mg l−1	2070	2600	2450	2280	2200	4210	8640	8740	6760	5190	11700
Mg	mg l−1	12.6	17.5	30	48.2	88.1	115	25.2	25.5	27.1	27.8	23.4
Na	mg l−1	1490	1800	1740	1620	1450	1780	3010	2990	2320	1800	2910
Br	mg l−1	38	48	44	41	37	62	120	119	92	73	182
Cl	mg l−1	6430	7760	6830	6410	6250	9590	15800	19000	13700	13200	33000
SO4	mg l−1	<10	<10	<10	<10	<10	16	15	<10	<10	<10	<10
TDS	g l−1	10	12	11	10	10	16	28	31	23	20	48
EC	mS m−1	1640	1940	1760	1760	1700	2940	5400	5220	4110	3330	6450
Alk	mmol l−1	0.48	0.25	0.23	0.32	0.25	0.34	0.37	0.77	2.55	1.47	0.39
NO3	mg l−1	<20	<20	<20	<20	<20	<20	<20	<20	<20	<20	<20
PO4	mg l−1	<0.02	0.07	0.10	0.09	0.16	<0.2	<0.2	<0.2	<0.2	<0.2	<0.2

Abbreviations: DGGE, denaturing gradient gel electrophoresis; n.d., not detected; TDS, total dissolved solids.