The Geochemical Exploration Model Of Tin Deposits In Northeastern Guangxi, China

The northeastern Guangxi is an important tin deposits’ cluster in China, which is famous for large or super-large tin deposits. Three typical tin deposits are selected here to construct geochemical exploration model of tin deposit, which are Shanhu tungsten-tin deposit, Limu tin-polymetallic deposit and Shuiyanba tin deposits. Based on summarizing the geological outline, regional rocks and 1:200,000 stream sediments characteristics of the three typical tin deposits above, this thesis is committed to the research of the geologic features and geochemical characteristics of the tin deposits in northeastern Guangxi. Also, the geochemical exploration model of the tin deposits in northeastern Guangxi has been established in this thesis. The main knowledge is acquired as follows:For the tin ore concentration area in northeastern Guangxi, the rock indicator element combination of the geochemical explorative prospecting includes ten hydrothermal ore-forming elements(W, Sn, Mo, Bi, Cu, Pb, Cd, Ag, As, Sb), one hydrothermal ore-hauling element(F), two rock-forming trace elements(Li, Be), two acid trace elements(Nb,U) and one basic trace element(Ni). There are 16 elements in total. Generally speaking, the anomaly intensity of the main mineralizing element(Sn) is greater than 5. The anomaly intensity of the associated elements(Ag, W, Sb) is greater than 4. The anomaly intensity of the associated elements(As, Bi, Cd, Cu, Li, Ni, Pb) is greater than 3. The anomaly intensity of the associated elements(F, Mo, Nb, U) is greater than 2. The anomaly intensity of the associated element(Be) is greater than 1.For the tin ore concentration area in northeastern Guangxi, the regional indicator element combination of the geochemical explorative prospecting includes nine hydrothermal ore-forming elements(W, Sn, Bi, Cu, Pb, Cd, Ag, As, Sb), two hydrothermal ore-hauling element(B, F), two rock-forming trace elements(Li, Be). There are 13 elements in total. Generally speaking, the anomaly intensity of the main mineralizing element(Sn) is greater than 5. The anomaly intensity of the associated element(W) is greater than 5. The anomaly intensity of the associated element(Be) is greater than 4. The anomaly intensity of the associated elements(Ag, As, Cd, Pb, Sb) is greater than 3. The anomaly intensity of the associated elements(B, F) is greater than 2. The anomaly intensity of the associated elements(Bi, Cu, Li) is greater than 1.In the tin ore concentration area of the northeastern Guangxi, the enrichment characteristics of the elements( W, Sn, Bi, Cu, Pb, Cd, Ag, As, Sb, F, Li, Be) show the good succession in the geochemical process from the bed rocks to the stream sediments. However, due to the weathering, leaching influence and the enrichment effect, the anomaly intensity of these elements shows the variability to some extent, that is to say, the anomaly intensity tends to weaken or strengthen.In summary, the prospecting indicator element combination of the tin ore concentration area is a total of 12 elements, namely, W, Sn, Bi, Cu, Pb, Cd, Ag, As, Sb, F, Li, Be.