青藏高原高寒湖泊区花岗岩残积风化壳地球化学若干特点——以措莫隆锡多金属矿区为例

CHARACTERISTICS OF GRANITE RESIDUAL WEATHERING CRUSTS IN THE SUBNIVAL LAKE AREA OF QINGHAI-TIBET PLATEAU: A CASE STUDY OF THE CUOMOLONG Sn-POLYMETALLIC ORE DISTRICT

被高山稀疏灌丛草甸覆盖的高寒湖泊区内薄层花岗岩残积风化壳,属于硅铝质弱酸性—酸性的淋溶型风化壳,从中不同程度地淋失了Na2O、CaO、K2O、SiO2和绝大多数风化母岩中具有较高含量的微量元素(B、Bi、Zn、Nb、Be、Sr、F、Ag等)。Al2O3基本稳定,略有淋失。其中不同程度地滞留集聚了TFe、MgO、TiO2、P2O5、TMn,母岩中具有较高含量的Sn、Mo、Zr及许多低含量的微量元素(Hg、Cu、Ni、Co、Li等)。

Thin-layered granite residual weathering crusts covered by high mountain sparse bush and meadow in the subnival lake area belong to the alumino-siliceous weakly acid - acid leaching type, with the leaching of Na2O, CaO K2O, SiO2 in different degrees. Most weathered parent rocks have relatively high trace elements such as B, Bi, Zn, Nb, La, Be, Sr, F and Ag. Al2O3 is basically stable, and TFe, MgO, TiO2 , P2O5 and TMn have been somewhat accumulated. There are also high contents of Sn, Mo and Zr and low contents of Hg, Cu, Ni, Co and Li in parent rocks.