Petrographic characteristics of the brecciated coals from Panxian county, Guizhou, southwestern China

Abstract

In this paper we report the petrological characteristics of the high volatile A bituminous coal from the Yueliangtian coalfield, Guizhou, southwestern China. The random reflectance and maceral quantities were measured by a Leitz Orthoplan microscope. The maceral assemblages are dominated by collodetrinite, fusinite, and semifusinite. Occurring to a lesser extent are telinite, collotelinite, micrinite, and sporinite; along with traces of vitrodetrinite, corpogelinite, macrinite, secretinite, inertodetrinite, cutinite, resinite, and liptodetrinite; and, in some cases, exudatinite, barkinite, as well as funginite. Degraded vitrinite, fusinite, and semifusinite coupled with fecal pellet-derived macrinite revealed that fungi or bacteria participated in the formation of the peat. Funginite, hyphae, and fungus rootlets observed in the coal further confirmed microbial participation. The studied coal seam, especially the lower portion, displays typical attributes of brecciation: vitrinites exhibited crumbled, deformed, and uneven occurrences based on the degree and extent of tectonic movements they suffered; fusinite and/or semifusinite fragments were dispersed or cemented by gelinite or exudatinite; and carbonate and carbonate-pyrite mineralization occurred in the cell lumens of fusinite/semifusinite and carbonate veins, respectively. The Panxian fault westwards of the Yueliangtian coalfield plus other tectonic movements are responsible for brecciation in the studied coals. Faded resinite and telinite verified oxidation in the peat deposit.