阿尔泰山克木齐河中游阶地砂金矿的粒度特征与环境意义

A PRELIMINARY STUDY ON THE CHARACTERISTICS OF GRAIN SIZE AND SEDIMENT ENVIRONMENT OF KEMUQI GOID-PLACER,ALTAI MOUNTAINS

克木齐河中游Ⅲ级阶地沉积物粒度特征表明,矿层与盖层具有明显不同的沉积条件,含矿沉积物形成于高能环境下,因此分选差.粉砂粘土含量高,砾石长轴优势方向与水流平行覆盖其上的沉积物分选较好,平均粒径大,粘土粉砂含量低,应属水流较稳定环境下的产物,水流能量的这种周期性变化是导致砂金富集的有利因素之一。

Kemuqi gold-placer area is an important part of Xishan region where has been fa-mous for producting placer-gold for a long time. A primary study on grain-size andsedimental environment of the placer shows that the deposits with rich placer golds areusually characterized by a higher percentage of silt and clay and poorly-sorting. Accordingto the analysis, the authors believe that the deposits belong to a kind of fluvial sediment. Itis different from the overlying sediment. The cause of formation of the placer is a long andcomplex process. The placer-gold was mainly produced in the period when the flow had avery strong energy to transport the debris. So the flow power play an important role intransporting and depositing placer-golds in Altai Mountains.