Geobotanical and Biogeochemical Prospecting Method of Complex Sulphide Ore of Pb-Zn-Cu-Ba in Abuni-Adudu areas of the Middle Benue Trough, Nigeria

Abstract

This research work focused on two plant species namely, the Anogeissus leiocarpus (DC.) and Dichrostachys cinerea for mineral prospecting. The two plants were sampled based on their occurrence, abundance and outlook. Twelve samples (six each of Anogeissus leiocarpus (DC.) and Dichrostachys cinerea) were collected around Abuni-Adudu mining communities in the Middle Benue Trough, Nigeria. In addition, bulk ore and twelve soil samples were also collected and analysed for correlation. Geologically, the study area is made up compacted shale, baked shale (hornfels), and sandstones of sedimentary origin, which are intruded by tertiary basalts of igneous origin. Samples were analysed for elemental composition, using inductively coupled plasma mass spectrometry method. Analysis revealed that the geobotanical method of prospecting for Pb-Zn-Cu-Ba mineralization in the area is promising as biogeochemical data indicated that the Dichrostachys cinerea are good indicator of Pb-Zn-Cu mineralization while the Anogeissus leiocarpus were indicative of Barium. Given the relatively low concentration of Barium in the ore (3.8 ppm) as against concentration in the soil samples, which ranges from 83 ppm (sample YS6) to 552 ppm (sample YS12), Barium has its source from the shale and sandstone or nearby Barite mineralization and not the ore.

Keywords

• anogeissus leiocarpus dc, biogeochemistry, dichrostachys cinerea, geobotany, lead-zinc-copper ore