九华山第四纪泥砾沉积物成因分析

An Analysis on the Formation of the Mudstone of the Quaternary in Mt Jiuhua

九华山第四纪“泥砾沉积物”成因有很大争议。笔者通过野外采样，对“泥砾沉积物”进行了粒度分析，发现沉积物粒度频率曲线呈现双峰式、累积曲线平缓、粒度分布广泛；δ＿１介于１．５－２．０之间；Ｓｋ＿１，在０上下，趋向正偏态；ｋｇ在０．４５２－０．８１９７之间。上述粒度特征显示出间冰缘泥石流沉积物特征，其形成过程与冰缘环境有关。

Grain is an important structural characteristics of sediment.Analysis of grainis one of the important ways to study dcpositing enviroment.Through the analysis ofthe grain of the sediment of the Quaternary of Mt.Jiuhua,it shows that the frequencycurve of the grain of sediments takes in the form of double peaks;the accumulatingcurve is smooth,and the grain is widely distribution;δ_1 lies between 1.5-2.0;Sk_1nearly above 0,tending to be positive;and kg lies between 0.452-0.8197.The charac-teristics of the mudstone sediment of the Quatenary in Mt.Jiuhu was neither the sedi-ments of flowing water nor the glacial one. It was the sediment of mud-rock flow inthe interperiglacial environment of monsoon-type,but its formation caurse was got intouch with the periglacial environment of monsoon-type. So,it was the periglacial en-vionment of monsoon-type during the ice period of the Quaternary in Mt.Jiuhua.