Showing papers by "Gordon A. McFeters published in 1981"
TL;DR: Thermophilic sulfate‐reducing and methanogenic bacteria were detected in deep ground waters from geologic units that make up the Madison Formation, which underlies a large portion of the northern Great Plains.
Abstract: Thermophilic sulfate‐reducing and methanogenic bacteria were detected in deep (1200 to 1800 m) ground waters from geologic units that make up the Madison Formation, which underlies a large portion of the northern Great Plains. Some sulfate‐reducing bacteria were isolated and tentatively identified as Desulfotomaculum nigrificans. These organisms probably produce the hydrogen sulfide that is in the ground water. Direct microscopic counting methods demonstrated the presence of about 1000 bacteria/ml in the ground waters. Attempts to detect aerobic and other anaerobic bacteria were unsuccessful.
70 citations
TL;DR: Certain wells in coal and spoils aquifers contained substantial populations of iron-oxidizing acidophilic bacteria, however, these wells were always of alkaline or neutral pH, indicating that bacterial pyrite oxidation occurred where groundwaters contacted either replaced spoils or coal that contained pyrites or other metal sulfides.
Abstract: Spoils samples collected from a coal strip mine in southeastern Montana were examined for populations and activities of iron- and sulfur-oxidizing bacteria. Spoils examined were of three types: (a) acidic pyrite-rich waste coal, (b) oxidation halo material, and (c) alkaline material, which was the most widespread type. Bacterial numbers, sulfur oxidation, and14CO2 uptake activity declined to low levels in the summer when spoils were dry. Even in wetter spring months pyritic spoils contained relatively low numbers of acidophilic iron- and sulfur-oxidizing bacteria, probably indicative of water stress since the same spoils incubated with excess water or dilute mineral salts showed considerably greater bacterial numbers and activity. Certain wells in coal and spoils aquifers contained substantial populations of iron-oxidizing acidophilic bacteria. However, these wells were always of alkaline or neutral pH, indicating that bacterial pyrite oxidation occurred where groundwaters contacted either replaced spoils or coal that contained pyrite or other metal sulfides. Bacterial activity may contribute to trace metal and sulfate leaching in the area.
11 citations