稳定湖相沉积物和风成黄土粒度判别函数的建立及其意义  

The Significance and Establishment of Discriminant Function with Grain Size of Stable Lacustrine Sediment and Eolian Loess

作　　者：张平[1] 宋春晖[1] 杨用彪[1] 高红山[1] 张红艳[2] 刘维明[1] 潘美慧[1] 刘平[1] 胡思虎[1] 夏维民[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室与资源环境学院,兰州730000 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075

出　　处：《沉积学报》2008年第3期501-507,共7页Acta Sedimentologica Sinica

基　　金：国家重点基础研究发展计划项目(编号:2004CB720201);中国科学院知识创新工程重要方向项目(编号:k2CX2-YW-104);国家自然科学基金项目(批准号:40721061,40334038);教育部科学研究重大项目(编号:306016)资助

摘　　要：沉积物粒度变化主要受搬运介质、搬运方式、沉积环境和气候等多种因素的控制,通过粒度分析可判别沉积物的成因类型,推断其形成的沉积环境,解释环境演变。利用统计学方法对典型稳定湖相沉积物(罗布泊湖相样品282块,岱海湖相样品123块)和典型风成黄土(甘肃兰州榆中样品263块)粒度参数进行定量化分析,并经稳定湖相和风成沉积物验证,获得稳定湖相与风成沉积物的判别公式:F(湖相、风成沉积物)=20.363Mz-56.371Sd-67.922Sk+23.516Kg-55.626,若F>0,为稳定湖相沉积物,反之,F<0,则为风成沉积物。这为研究地史中稳定湖泊与风成环境沉积物的鉴别提供粒度分析定量化判别方法,它对陆相古环境、干旱化事件和尘暴事件等研究具有十分重要的借鉴价值。Changes in sediment grain-size are mainly controlled by the transporting medium, transporting mode, depositional environment, climate and other factors. Through analyzing characteristic of grain-size, types of sediments can be distinguished, and that characteristic of the sedimentary environment can be concluded, environmental evolution can be interpreted. In this paper, the samples include typical stable lacustrine sediments （282 lacustrine sediment samples from Lop Nur, 123 lacustrine sediment samples from Daihai） and typical eolian loess （263 samples from Lanzhou）. The grain-size characteristic parameters of these samples are obtained with moment method. This article quantitative analyzes these parameters by means of discriminatory-analytical method. And then obtained discriminant function of stable lacustrine sediments and typical eolian sediments： F （lake,eolian sediment） = 20. 363Mz - 56. 371Sd - 67. 922Sk ＋ 23 . 516Kg-55. 626, if F 〉 0, the sediment is stable lacustrine sediment; if F 〈 0, the sediment is eolian sediment. This is a good quantitative analysis to the stable lacustrine sediments and eolian sediments of geological history, as well as a significant for the basis for distinguish eolian components from the sequence of paleo-lacustrine sediments. And it is investigation of terrestrial paleoenvironments, drought events and dust-storm events.

关 键 词：稳定湖相沉积物 风成黄土 粒度分析 判别函数 

分 类 号：P512.2[天文地球—地质学]