Petrography and Paleobotany of a Petrified Paleocene Peat and Its Bearing on the Coalification of Lignite
Francis T. C. Ting, 1977. "Petrography and Paleobotany of a Petrified Paleocene Peat and Its Bearing on the Coalification of Lignite", Interdisciplinary Studies of Peat and Coal Origins, P. H. Given, A. D. Cohen
Download citation file:
The discovery of a silicified Paleocene peat in a lignite bed in Western North Dakota has provided detailed anatomical information on the Paleocene.peat forming plants. It also provides an opportunity for investigating the processes of coalification of lignite by direct comparison of ptrographie components of petrified peat and lignite.
Most of the well preserved plant debris consists of conifer stems, twigs, roots, and leaves. Other plant organs and tissues include seeds, pollen grains and spores, fern sporangia and annuli, and parenchymatous tissues of unknown origin. Palynological data indicate the presence of abundant angiosperms; yet, except for the presence of pollen grains and possibly certain unidentifiable, decomposed leaves and leaf cuticles, there is little evidence to indicate the presence of angiosperm wood in the petrified peat and the lignite. Field evidences indicate that the compaction ratio from peat to lignite is 3 or 4 to 1. Microscopic examination of the petrified peat and the lignite reveals that much of the compaction takes place at the expense of the interstitial spaces and the collapsing of cell cavities. The lignite also exhibits a much higher degree of glification thah does the peat
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.