宜宾-重庆段川江高阶地物质来源的定量分析--判别分析在重矿物分析中的应用

川江倒流的问题可以利用川江高阶地的物质来源进行佐证，如果川江上段高阶地的物质来源于东部而不是西部，则川江就有倒流的可能性。重矿物组合可以部分地表征物质来源。对宜宾－重庆段川江高阶地的重矿物种类及其含量做了判别分析，得到了比较理想的结果。将金沙江和重庆以下的重矿物组合特征作为已知的两个分类，判别重庆以上（包括宜宾和重庆的样品）的高阶地重矿物组合特征究竟应该属于哪种类型。以重矿物种类和含量为变量进行分析的回代结果正确率分别为93.1%和96.6%。川江高阶地重矿物组合与金沙江差异较大，估计当时该阶地物质来源与金沙江关系不大。

A QUANTITATIVE ANALYSIS FOR THE PROVENANCE OF THE HIGHER TERRACES IN THE UPPER REACH OF CHUANJIANG RIVER--AN APPLICATION OF STEPWISE DISCRIMINATION ANALYSIS TO THE HEAVY MINERAL ASSEMBLAGE

The refluence of Chuangjiang River can be partly proved by the provenance of its higher terraces.The refluence had possibly occurred if the sediment originate form east but not west.The heavy mineral assemblage represents partly the provenance.Stepwise discrimination analysis has been used in the study of heavy mineral assemblage.The authors regarded the samples of Jinsha River and the lower reach below Chongqing of Chuangjiang River as the two original categories,and discriminate which type should the higher terraces of the section above Chongqing City belongs to.And the section above Chongqing City included Yibin City,Luzhou City and Chongqing City.The variables are the varieties and percentages of heavy minerals.The correct ratios of re-entering into the model are 93.1% and 96.6%,respectively.It can be concluded that the upper reach of Chuangjiang River is more similar to the lower reach of Chuangjiang River than to the Jinsha River in the heavy mineral assemblage.