CHEN Yang, MENG Meng-ping, SONG Ci-an*

(Key Laboratory of Concealed Metallic Ore Resources Eploration College of Geoscience, Guilin University of Science and Technology, Guilin 541004, China)

Abstract: This study investigated the influence of plants growing above the ore deposit on the absorption of ore-forming and associated elements in soil and the formation of biogeochemical anomalies as exemplified by the Yantianling cassitirite-sulfide ore deposit. It also examined the contents and characteristics of elements in different soil layers and in different organs of China fir, strawberry trees and decrano pteris ped growing above. It was found that the contents of most ore-forming and associated elements in the plants growing above the ore deposit are higher than the background values, thus causing biogeochemical anomalies. The soil is enriched in As, Sb, Bi, Hg, Sn and W, showing no anomaly in plants. The elements are highly accumulated in roots or in leaves and fine branches, but depleted in xylem and skin. Relative to the background zone, the capability of plants growing in mineralization anomaly zones to transport and absorb most elements is relatively decreased to different degrees, but the case is not serious for those trophic and less toxic elements and highly serious for those greatly toxic or unsoluable elements. The aborption and transfer of trophic or less toxic elements in soil by plants may be accessible-semi-accessible , but those of greatly toxic or indissoluble elements may be inaccessible. Inaccessbile-semi-accessible type elements may produce good biogeochemical anomalies, while inaccessbile-type elements may produce no biogeochemical anomaly or unremarkable anomaly. The transfer of greatly toxic elements from roots to leaves may be obstructed, and the leaf anomaly may be unobvious or could not be produced, but remarkable root anomalies would be possible.

Key words: microelement; bio-absorption and transfer; barrier effect; cassiterite-sulfide ore deposit 

EARTH AND ENVIRONMENT Vol. 40, No.2, Tot No.288, 2012, Page 208-218