辽宁盘锦荣兴港作业区MT19钻孔海洋沉积物粒度特征

Analysis of grain size characteristics of marine sediments in Drilling Hole MT19 of the operation area of Rongxing Port,Panjin,Liaoning Province

使用激光粒度分析仪对辽宁盘锦荣兴港MT19钻孔6个样品进行分析,运用福克-沃德(Folk-Ward)图解法计算相关粒度参数并绘制输出粒度频率特征曲线。结果表明:盘锦荣兴港沉积物中黏土(d<0.0040 mm)的体积分数最小,平均值为8.49%;粉砂(0.0040~0.063 mm)的体积分数较大,平均值为38.39%;砂(0.063~2.00 mm)的体积分数变化较大,平均值为53.13%。Shepard沉积物三角形分类图解表明,研究区沉积物类型多属于粉砂质黏土和黏土质粉砂;粒度频率曲线显示,除MT19-2-2号样品为主次三峰型外,其余均为主次双峰型,说明该区域在海进-海退过程中的某些时段沉积环境相似,出现了沉积物粒径组合及大小相似的情况。

The data of six experimental samples of Drilling Hole MT19 in Rongxing Port of Panjin were studied by laser particle size analyzer.The granularity parameters were calculated by Folk-Ward graphic method and the granularity frequency curves were drawn.The results show that:among the Rongxing Port sediments,the mass fraction of clay(d<0.0040 mm)is the smallest with an average of 8.49%;the volume fraction of silt(0.0040-0.063 mm)is larger with an average of 38.39%;the volume fraction of sand(0.063-2.0 mm)fluctuates,with an average of 53.13%.The triangular classification of Shepard sediments indicates that the sediment types in the study area are mostly silty clay and clay silt.The granularity frequency curves show that except for the MT19-2-2 sample(primary and secondary three-peak pattern),the other samples are of primary and secondary bimodal pattern.Thus,it is proposed that during certain transgressive-regressive periods,the sedimentary environment of this area was similar,and the sediment particle size combination and sizes were similar.