十里镇三叠系沉积岩粒度特征与沉积环境分析  

Grain Size Characteristics of Sediments and Sedimentary Environment of the Triassic Rocks of the Shili Town

作　　者：赵恩全 柳晓东 李明[2] 白洁 温晖 ZHAO En-quan;LIU Xiao-dong;LI Ming;BAI Jie;WEN Hui(Langfang Natural Resources Comprehensive Survey Center,China Geological Survey,Langfang 065000,China;Natural Resources Comprehensive Survey Command Center,China Geological Survey,Beijing 100055,China)

机构地区：[1]中国地质调查局廊坊自然资源综合调查中心,河北廊坊065000 [2]中国地质调查局自然资源综合调查指挥中心,北京100055

出　　处：《河北地质大学学报》2024年第4期11-18,共8页Journal of Hebei Geo University

基　　金：中国地质调查局专项调查项目(DD010614)。

摘　　要：沉积岩粒度特征可以反应其沉积环境。经过野外调查取样,在室内分析直沟隆务河群地层岩石粒度组成,计算样品平均粒径、峰度、偏度和分选系数,借助粒度标准偏差与偏度离散图、C-M图等粒度分析图件,综合分析样品粒度分布特征。样品粒度频率曲线峰值一半大于2Φ小于4Φ,另一半大于4Φ,峰值特点显示样品主要为细砂和粉砂;频率曲线均为单峰态,峰值范围变化较小;平均粒径范围在2.9Φ~4.5Φ,主要集中在3.5Φ~4.5Φ,主要为细砂和粉砂,分选程度主要为分选中等—较好;峰态值主要表现为中等峰态,其次是宽峰态特点;偏度主要呈近对称,其次是负偏态;样品的相关粒度参数离散图中均显示为海滩环境。综合分析结果表明:甘肃岷县十里镇直沟地区三叠系地层的沉积环境属无障壁海岸沉积环境。The grain size characteristics of sedimentary rocks can reflect the sedimentary environment.After collecting the typical horizon sandstone samples and indoor particle size tests,analyzing the grain size composition,average grain size,kurtosis,sorting coefficient and skewness of the Longwu River Group in Zhigou,at the same time,particle size distribution maps such as standard deviation and skew-ness discrete graph,C-M diagram were used to analyze the particle size distribution characteristics of the samples.Half of the peak value of the sample size frequency curve is greater than 2Φand less than 4Φ,and the other half is greater than 4Φ.The characteristics of the peak value show that the sample is mainly fine sand and silty sand.The frequency curves are unimodal,and the range of peak values varies little.The average particle size ranges from 2.9Φ~4.5Φ,mainly concentrated in 3.5Φ~4.5Φ,mainly fine sand and silty sand,the sorting degree was mainly medium to good.The kurtosis is mainly medium granularity kurtosis,followed by wide granularity kurtosis.The skewness is mainly near symmetric,followed by negative skewness.The standard deviation and skewness discrete graph and the kurtosis and skewness discrete graph of the sample show the beach environment.The comprehensive analysis results show that the sed-imentary environment of Minxian Shili Town Zhigou area,Triassic strata is non barrier coastal sedimentary environment.

关 键 词：粒度分析 隆务河群 海相沉积 

分 类 号：P512.2[天文地球—地质学]