Table 3. Dissolved and free gas composition in white mat (WM), transition zone (TZ) and background (BG) areas.

Sample	H2	O2	N2	CO2	CH4	CO
WM Free Gas (%)	b.d.	2.72	18.00	61.36	0.299	0.025
WM Dissolved Gas at 10cm (μM)	b.d.	0.496	38.5	11.93	0.038	0.076
TZ Dissolved Gas at 5cm (μM)	b.d.	1.001	76.6	2.725	0.089	b.d.
BG (μM)	b.d.	220	456.00	2.638	b.d.	b.d.
End-member (average) (μM)	0	0	0	47.304	0.183	0.365