【作者】 阎浩；

【导师】 杨桂芳； 王书兵；

【作者基本信息】 中国地质大学（北京） ， 地理学， 2010， 硕士

【摘要】 以内蒙古托克托县郝家窑湖相沉积剖面为研究对象,通过岩石地层学、地貌沉积学方法,结合野外记录,将剖面大致分为3个总阶段,在阶段2中又细分为3个次级阶段,建立了郝家窑剖面沉积地层序列。郝家窑剖面厚47米,上部风成黄土(城川组)厚3.5米,其年龄是94.5～19.3Ka BP,地质年代属晚更新世;萨拉乌苏组厚43.5米,顶界年龄为99.3kaBP,底部年龄为144.4kaBP,地质时代跨越中晚更新世;两者之间存在沉积间断。郝家窑剖面粒度中值粒径平均为59.75μm,粒度总体以砂和粉砂为主,下部地层以分选相对较差的粗粒的砂组成,上部以分选较好的细粒的粉砂和粘土组成。频率曲线有双峰、三峰和四峰等三种类型,在纵向各层段,频率曲线变化明显。郝家窑剖面LOI550与平均粒径、细粒的粘土、细粉砂呈较好的正相关关系,与粗粒的砂和细砂呈现反相关关系;LOI950与粒级各组分间均显示较差的相关性。剖面中,细颗粒、高LOI550值指示气候干冷;粗颗粒、低LOI550值指示气候湿润;LOI950与环境关系复杂。萨拉乌苏组记录了氧同位素5b～6b阶段环境变化特征,环境与格陵兰冰芯记录基本一致,与董哥洞石笋记录差别较大,表明托克托地区环境主要受控于东亚季风,受西南季风影响较小;同时,与格陵兰冰芯记录并不完全一致,反映了一种区域性气候的环境变化。更多还原

【Abstract】 Based on methods of lithostratigraph, geomorphology and sedimentlogy as well as the field work, the paper deals with the lacustrine deposits from the Haojiayao section in Tuoketuo town, Inner Mongolia Autonomous Region.The depositional sequence of the Haojiayao section has been established as it could be divided into three depositional stages and the second stage includes three sub-stages.Haojiayao section is 47m thick in all.The upper part of the section is covered by loess from Chengchuan formation whose thickness is 3.5m,its deposition period is from 94.5 Ka BP to 19.3 Ka BP which belong to Late Pleistocene; Salawusu formation is 43.5m thick whose period is from 144.4 Ka BP to 99.3 Ka BP. It links Middle and Late Pleistocene and their deposition is disconnected.The median grain-size of Haojiayao section is 59.75μm, Grain-size frequency curves indicates the main composition of haojiayao section is sand sediment and silt fraction, the lower strata of Haojiayao section is composed of bad sortable grit fraction, the top is composed of good sortable silt fraction. Frequency curves of sediment are divided into three types, they are double kurtosis, triplicate kurtosis and fourfold kurtosis; Grain-size distribution is consist of different components and frequency curves.The LOI550 section of Haojiaoyao is positive correlated to mean grain-size value, thin clay and silt but it is negative correlated to grit fraction and fine sands. The correlation between LOI950 and different grain is bad.Higher vaules of LOI550 section and that of fine grains indicate a warm-humid climate; The lower values of LOI550 section and that of corase grains indicate a cold- dry climate;the relation between LOI950 and environment is complicated.The Salawusu formation recorded the characterisitic of environmental change when oxygen isotope is in 5b-6b, its environmental recordining is identical to that of GRIP. The great various recordings between Salawusu formation and stalagmite in Dongge cave indicate environment in Tuoketuo was mainly dominated by monsoon from eastern Asian and its recording is not fully coincident with that of GRIP which reflect a special environmental change in regional climate.更多还原