VII.— The Banded Constituents of Coal
| Autor: | W. J. Skilling |
|---|---|
| Rok vydání: | 1935 |
| Předmět: | |
| Zdroj: | Transactions of the Geological Society of Glasgow. 19:270-284 |
| ISSN: | 2052-9422 0371-7224 |
| DOI: | 10.1144/transglas.19.2.270 |
| Popis: | 1. The Physical Characteristics of the Banded Constituents. In the course of this paper it is proposed to describe what have become known to us within recent years as the banded constituents of bituminous coal. Prior to the year 1919, investigators into the constitution of coal were content to describe its appearance as bright or dull according to the predominance of the bright or dull layers in the specimens under examination. There were, however, in addition to these hard, bright and dull bands, varying lenticles of soft, black, charcoal-like substance to which specific names such as “mineral charcoal” and “mother of coal” had been applied. Another distinctive material forming part of some coal seams is cannel or “parrot” coal. This type of coal differs from the ordinary banded variety in its uniformity of texture, its satiny lustre and its marked conchoidal fracture. Its occurrence in coal seams is very uncertain and it is usually present in varying sized lenticular bands. In some publications it may be referred to as “boghead” coal owing to its similarity in appearance to the famous Torbanehill mineral. If a close inspection is made of a lump of ordinary bituminous coal, it will generally be found to consist of layers of materials whose power to reflect light varies considerably. There may be bands of bright, black, glassy lustre; bands of bright material which show minute striations; bands of dull, granular material; and, finally, lenticles of the soft, charcoal-like substance to which reference has already been made. It This 250-word extract was created in the absence of an abstract |
| Databáze: | OpenAIRE |
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