Abstract
Surface soil and stream sediments of 36 samples were analyzed in the Na Bop mining area for the major and minor elements by ICP/MS and total C and S by infrared methods. Important ore metals for the environment, such as arsenic, base metals and cadmium, are high in surface soils and stream sediments. Arsenic is positively correlated with iron and cadmium is also well correlated with zinc, implying that the arsenic and cadmium originated in the ore minerals of arsenoppyrite and sphalerite in the ores; then the minerals were moved into the surface materials.
Some of the ore components are enriched in soil and stream sediments below the Bac Can tailing pond along the NE-trending small valley (e.g., As & Pb, Figs. 4 & 5), but are low along the N-S trending main valley where sulfide orebodies cropping out. Soils are higher in the total C contents relative to stream sediments at the same sampling point, but no such tendencies are observed on the total S and As. The pollution is much smaller in scale relative to large copper mining area of the Hitachi mine, Japan, and the Karabash mine of Ural, Russia, where all the mining equipments including mineral separation and smelting plants were located. This study should further be extended much down stream side including agriculture lands and products.
