coal ball


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coal ball

[′kōl ‚bȯl]
(geology)
A subspherical mass containing mineral matter embedded with plant material, found in coal seams and overlying beds of the late Paleozoic.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Figure 8(a) indicates that a large part of rock (carbonaceous shale) balls are mixed in coal balls.
Coal balls in batter and fry until golden brown Drain on paper towels, then transfer lo large bowl with curry sauce.
Marie Stopes, the discovery of pteridosperms, and the origin of Carboniferous coal balls. Earth Sciences History 27, pp.
The first discovery of in situ coal balls in Nova Scotia.
By the nature of inherent limited size, coal balls cannot preserve the large parts of the fronds known to be borne by the arborescent alethopterid plant.