Grain Size Characteristics of Sediments and Sedimentary Environment of the Triassic Rocks of the Shili Town
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 2Φ and 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.
grain size analysisthe Longwu river groupmarine sedimentary environment
国家科技期刊平台
NSTL
万方数据
