Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8123619 | International Journal of Coal Geology | 2018 | 18 Pages |
Abstract
Minerals in the non-coal samples (partings and floor strata) appear to have responded differently to the metamorphic conditions than those in the adjacent coals. Possible mechanisms for the formation of NH4-illite in the Jincheng non-coal rocks at least involve isomorphous substitution of NH4 for K in the K-illite structure. The well-crystallized K-illite in the non-coal rocks probably formed from detrital K-illite, and wasrecrystallized with the coal rank advance. Absence or minor proportions of pyrophyllite in non-coal samples may be due to a lack of epigenetic kaolinite in the non-coal horizons. Pyrophyllitization occurred during a late stage of metamorphism. The general absence of chlorite in the thick non-coal interval is probably due to the low permeability of that horizon, which resulted in a lack of infiltrating Fe- and Mg-bearing fluids.
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Authors
Lei Zhao, Colin R. Ward, David French, Ian T. Graham, Shifeng Dai, Chao Yang, Panpan Xie, Siyu Zhang,