ASSESSMENT OF ENVIRONMENTAL-IMPACT OF COAL EXPLORATION AND EXPLOITATION IN THE DRAMA BASIN, NORTHEASTERN GREEK-MACEDONIA

Forty-three samples of lignites and their partings from sir boreholes from the Drama Basin, Macedonia, in northwestern Greece were analyzed for their mineralogy and geochemistry. Mineralogical analysis of low t emperature (120 degrees C) ashes indicates that quartz and gypsum are present in all samples, while feldspars, clay minerals, and pyrite are present in most samples. Amphiboles, magnetite, diopside, anatase, si derite, stromayerite, and kizerite are encountered in order of abundan ce in fewer samples. In addition, calcite is present in all partings. Mineralogical analysis of high temperature (855 degrees C) ashes revea ls the presence of quartz, feldspars, anhydrite, and hematite in most of the samples while maghemite, lime, and rutile are encountered in or der of abundance in fewer samples. Sulfur content of these lignites is low to medium (0.4-1.17 percent daf) and is mostly inorganic (sulfur associated with mineral matter). Sulfur associated with macerals (orga nic sulfur) as determined in low temperature ash ranges between 0.3-11 .9 percent of total sulfur. Most elements in these lignites are associ ated with mineral matter or do not show any preference, except Br, Hf; Mn, Mo, Sb, U, and V, which are bound to coal macerals (organic). The source of As, Mo, Sb, U, V, and W, which is encountered in high conce ntrations, is due to the surrounding crystalline rocks. These elements are mobilized and transported by surficial water, deposited syngeneti cally in the peat swamp and finally incorporated in the lignite.