青海高寒湖沼景观区风成沙对成矿元素迁移的扰动机制的研究

青海高寒湖沼景观区是风成沙沉降区,由于风成沙的干扰,水系沉积物-0目的粒级段多数元素异常大幅度降低,甚至消失.研究表明,风成沙扰动层的元素分维呈现突变特征.根据固定沙丘和流动沙丘优势粒级混合扰动特征,计算了粒级因素系数,试验结果说明粒级因素系数可以较好地描述风成沙混入量特征.用突变理论的折叠突变势函数公式,计算了组分扰动因素系数,计算结果与扫面试验结果非常吻合.高寒湖沼景观区域化探采样介质以-4(或-10)～+40目为宜.

THE DISTURBANCE MECHANISM OF THE EOLIAN SAND TO THE MIGRATION OF ORE-FORMING ELEMENTS IN STREAM SEDIMENTS IN QINGHAI PROVINCE

Cold lake landscape in Qinghai province is located in the area of eolian sand accumulation. Anomalies of most ore-forming elements in -40 mesh of stream sediments remarkably weaken or even disappear owing to the eolian sand disturbance. The research shows that the fractal dimension of ore-forming elements in the eolian sand disturbance part of stream sediments exhibits mutation character. The granularity factor coefficient was calculated according to the disturbance characterized by the mixture of flowing dene with fast dene. This coefficient seems to be a good index for the mixing quantity of eolian sand in stream sediments. The composition factor coefficient was also computed with fold function formula of function theory, which coincides with the regional experimental results. Thus, the sample media in regional geochemical exploration should be -4(or -10)～+40 mesh in cold lake landscape.