Abstract

Ore-forming elements and related ones in the Chợ Điền-Chợ Đồn area are distributed differently from the standard distribution pattern of elements in the geothermal ores. They are distributed in downward sequence as follows: SbSnBaCo(AgBeGaGeVW)AsMoCuPbBiCdZnNi; with paragenetic assemblages of elements ZnCdBiPbAg,  CuMo(Sn)As,  NiCoCr,  LaCeYBa. Thischaracteristics together with the nature of the ore bodies and geologic structure have facilitated the intensive exchange between the ore-forming solutions and the surrounding rocks.

- The degree of ore body denudation in the Chợ Điền - Chợ Đồn area is low with very high (Pb.Zn.Ba)/(Co.Ni.Sn) ratio. By subdividing in details structural zones for survey and additional collection of geochemical samples, indications of deeply buried ores in the area from Phia Khao Pass to Binh Chai Mine have been identified.