粒度分析在吉木萨尔凹陷梧桐沟组沉积相研究中的应用

Application of Particle Size Characteristics Analysis in Sedimentary Facies Research of the Permian Wutonggou Formation in the Jimusaer Depression

沉积物的粒度特征是判断沉积环境和水动力的良好标志,有助于沉积环境的判别.文章在岩芯观察的基础上,利用取芯井段粒度分析资料绘制粒度概率累积曲线,曲线特征表现为:"一段式"、"两段式"、"三段式"及"多段式",针对不同种类的曲线特征作了具体分析.同时,利用萨胡粒度判别函数和CM图解进行判别,分别表现出自物源区向凹陷中心依次为冲积扇相、辫状河三角洲相、浊流相特征.粒度综合特征显示了吉木萨尔凹陷东部受牵引流的作用为主,凹陷中心受浊流的强烈影响.

Particle size characteristics of sediments is a good sign of judgment of sedimentary environment and water power, contribute to the determination of sedimentary environments. Based on the core observation, a large number of probability cumulative grain size curves were plotted using the date of particle size annlysis of coring wells.There were four different types of curves： one-segment pattern、wo-segment pattern, three-segment pattern, multi-segment pattern, and the feature of different types curves were ana- lyzed in detail. At the same time,combined with its selectivity, skewness 、 peakedness, and so on. Turbidites and Delta （river） depositional environment were identified through the use of Sahu discriminant function of particle size and CM diagram.Curve characteristics of particle size show traction current role and turbidity of depression center,which strongly infuenced the sedimentary environment on the edge of the eastern slope.