TABLE 1.

General description of mat samples

Mat samples	Geothermal area	Temp (°C)	pH	[S2−] (μM)	Chloroflexus-like	Cyanobacteria	Sampling dated
NMA sourcea	Mammoth Terraces	58.9	6.1	133	+	−	05-12-1995
NMA downstreama	Mammoth Terraces	56.3	6.4	19	+	+	05-12-1995
Tangerine Springb	Mammoth Terraces	60	6.4	40	+	+	26-08-1999
Mushroom Springc	Lower Geyser Basin	64	8.3	BDe	+	+	25-08-1997
Octopus Springc	Lower Geyser Basin	58-64	8.3	BD	+	+	27-08-1997

^aPreviously reported by van der Meer et al. (39).

^bOn the shoulder of Orange Mound Spring along the Mammoth Upper Terrace loop road.

^cSee Ward et al. (45) and Ramsing et al. (28) for location.

^dDay-month-year.

^eBD, below detection.