Elemental Composition of Fluvial-Lacustrine and Lacustrine Coal-Bearing Environments, British Columbia, Canada
2020
Goodarzi, Fariborz | Gentzis, Thomas | Hofmeister, Mark
Coal and interbedded rocks from the two coalfields in the southern intermontane region of British Columbia, Canada, deposited in fluvial-lacustrine, and lacustrine were examined using reflected light microscopy, instrumental neutron activation analysis (INAA), and inductively coupled plasma optical emission spectroscopy (ICPOES). Coals were deposited in the Paleogene period and under lacustrine (Hat Creek coalfields) and fluvial-lacustrine (Tulameen coalfield) conditions. The thorium/uranium ratio decreases rapidly with increasing authigenic uranium in the lacustrine Hat Creek. The Th/U ratio decreased slowly with increasing authigenic uranium in the fluvial setting due to a higher rate of sedimentation and an autochthonous origin of uranium. The intermontane coals have very low sulfur and pyrite content, typical of coals deposited in a freshwater environment. The elements of calcium, iron, magnesium, and manganese in these coals are found in the carbonate minerals ankerite, calcite, dolomite, and siderite and follow similar enrichment and depletion trends within the coal-bearing strata. The coal-bearing section in Tulameen is faulted. Some of the beds associated with major faults developed slickensides and became brittle. These beds have a high concentration of iron (38.5%), calcium (13.2%), and titanium (1.1%), which was the result of input by groundwater associated with the adjacent intrusive and extrusive rocks. Barium has a positive relationship with calcium, indicating its association with carbonates. Coals in the Hat Creek coalfield have high vanadium content with an average of 126 ppm compared to World coal (2–100 ppm). One coal sample (ash content = 13 wt %) has the highest vanadium content recorded in Canadian coals (897 ppm).
显示更多 [+] 显示较少 [-]