Environmental Aspects of Marsh Gases
Marsh gas samples collected from fresh-water marshes in Minnesota, Louisiana and Delaware, having waters near neutrality and weakly negative to weakly positive Eh, yielded larger methane flows than brackish water and salt-water marshes in Delaware and Louisiana with more negative Eh values. Carbon dioxide, nitrogen, carbon monoxide, hydrogen, and propane are other common constituees of the marsh gases. Hydrogen sulfide is less abundant in the fresh-water than in the brackish and salt-water marshes. Other marsh conditions relating,to methane genesis include salinity, sulfate content, turbidity, rainfall, tidal action, and source material.
Figures & Tables
This publication represents the proceedings, of a symposium on The Geology, Paleobotany, Geochemistry, and Microbiology of Peats." The symposium was held during the Annual Meeting of the Geological Society of America and associated societies, which took place in Miami, 18-20 November, 1974, and was jointly sponsored by the Coal Geology Division of the Society and the Organic Geochemistry Division of the Geochemical Society. Fourteen papers were presented, and nine are included in this publication. Five authors elected to make other arrangements for publishing their work; but the abstracts of these five papers, as submitted for inclusion in Abstracts with Programs, volume 6, number 7, 1974, are included here for completeness. Peats are of interest to scientists in a variety of disciplines: coal geology, organic geochemistry, soil science, plant ecology, the general ecology of food chains, agronomy, and environmental studies. Workers in many of these fields contributed to this symposium, but it is perhaps fair to say that the central unifying core is the consideration of peat as the precursor of coal. From a broad and general earth science point of view, peats and coals are of special interest because (a) such sediments contain higher concentrations of organic matter than any other common sedimentary deposits, and (b) in most peat beds and coal seams, the greater part of the organic matter and part of the mineral matter are autochthonous in the strictest sense, so that the many biological and chemical fossils that they contain are valid indicators of the organisms from which the organic matter was derived or of the environment of deposition. By contrast, although the reservoir and source rocks of petroleum do contain chemical fossils indicating their origin, reservoir rocks at least, cannot, of their nature, contain relevant fossils in the ordinary biological sense.