Energy, Énergie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géochimie, Geochemistry, Géochimie des sols et des roches, Soil and rock geochemistry, Roches sédimentaires, Sedimentary rocks, Charbon, Coal, Amérique du Nord, North America, America del norte, Argile minéral, clay minerals, Arcilla mineral, Cénozoïque, Cenozoic, Cenozoico, Eocène, Eocene, Eoceno, Paléogène, Paleogene, Paleógeno, Phanérozoïque, Phanerozoic, Fanerozoico, Phyllosilicate, sheet silicates, Filosilicato, Roche carbonée, carbonaceous rocks, Roca carbonosa, Roche clastique, clastic rocks, Roca clástica, Roche sédimentaire, sedimentary rocks, Roca sedimentaria, Silicate, silicates, Silicato, Tectosilicate, framework silicates, Tertiaire, Tertiary, Terciario, Analyse diffraction RX, X-ray diffraction analysis, Analyse éléments traces, trace-element analyses, Análisis elementos traza, Argile, clay, Arcilla, Basse température, low temperature, Baja temperatura, Cendre volcanique, volcanic ash, Ceniza volcánica, Charbon, coal, Carbón, Degré houillification, rank, Grado hullificación, Diffraction RX, X-ray diffraction, Difracción RX, Donnée MEB, SEM data, Dato MEB, Elément trace, trace elements, Eocène moyen, middle Eocene, Eoceno medio, Eocène sup, upper Eocene, Eoceno sup, Illite, illite, Kaolinite, kaolinite, Caolinita, Matière volatile, volatiles, Materia volátil, Mercure, mercury, Mercurio, Milieu deltaïque, deltaic environment, Medio deltaico, Milieu intertidal, intertidal environment, Medio intertidal, Mine charbon, coal mines, Quartz, quartz, Cuarzo, Shale, shale, Esquisto, Smectite, smectite, Esmectita, Tonstein, tonstein, Coal, Mercury: Modes of occurrence, Mineralogy, Trace elements, and Washington
Upper middle and upper Eocene coal-bearing strata in the Green River coal district of Washington state are in the Franklin coal zone of the undivided Puget Group. Coal-bearing strata accumulated in intertidal and deltaic environments along a tidally influenced delta plain. Numerous shale and tonstein partings within the coals indicate that the coal formed in low-lying peat mires. To evaluate variations in element distribution within these coals, vertical bench channel samples from the Franklin No. 7-8-9 (n =24) and the No. 10 (n = 11) coal beds were collected. Coal beds in the John Henry No. 1 mine of the Green River coal district have an apparent rank of high volatile B bituminous. No. 7-8-9 and No. 10 have a mean sulfur content of 0.67 wt.% and 0.9 wt.% respectively. When compared statistically to other western U.S. Tertiary coals, the Franklin coal zone in the John Henry No. 1 mine Franklin coal zone is significantly higher in contents of ash, Si, Al, Mg, K, Ti, Ag, As, Cu, F, Ga, Hg, Li, Nb, Ni, P, Sc, Sr, V, Y, Yb, and Zr, and has significantly lower contents of Ca, Na, B, Nd, and Se. Mean contents of several elements in the Franklin No. 7-8-9 and No. 10 coal beds are uncommonly high compared to western U.S. Tertiary coals. The No. 7-8-9 bed is higher in As (6.6X, 44 ppm), Cu (3.8X, 42 ppm), F (3X, 190 ppm), Hg (44X, 4.4 ppm), Mn (3.4X, 170 ppm), Nb (4.4X, 10 ppm), Ni (3.5X, 16 ppm), V (4X, 68 ppm), and Zr (4.9X, 88 ppm). The No. 10 bed is higher in As (11X, 81 ppm), Cu (3.2X, 35 ppm), Hg (75X, 7.5 ppm), Ni (3.3X, 15 ppm), P (5.4X, 1300 ppm), Sc (4.1X, 8 ppm), Sr (2.5X, 680 ppm), V (3.7X, 63 ppm), and Zr (2.7X, 48 ppm). X-ray diffraction analysis of the low-temperature ash from these coals reveals the predominance of quartz and clays (kaolinite, minor illite, smectite group, and mixed layer) and minor plagiociase feldspar (albite, disordered, and ordered Ca-bearing), carbonate (ankerite, calcite, kutnohorite, and siderite), pyrite, and clinoptilolite.