筛分法和激光粒度法联合测定陆源碎屑岩粒度

用筛分法和激光粒度法联合测定陆源碎屑岩粒度,对激光粒度法的分析数据进行了校正,以保证两种方法的分析数据配套衔接。通过对比不同地质年代沉积岩的岩心校正前后概率累积频率曲线,校正后的曲线能更好地表征碎屑岩粒度的分布。对影响马尔文Mastersizer 2000激光粒度仪背景测量的进样器搅拌转速A、泵速B、超声强度C三个因子进行L9(34)正交优化设计,筛选出最优的测量条件是A取600r/min,B取2000r/min,可使背景测量稳定,并得出它们对背景测量影响程度可用B>A>误差>C表示。用仪器自带的9个标准物质校正了粒度标准曲线,粒度标准曲线与仪器标准曲线的加权残差小,在0.795%～2.934%之间。该方法相对标准偏差在0.24%～0.33%之间,适用于各种地质年代陆源碎屑岩的粒度分析。

Granularity of Terrigenous Clastic Rock Using Sieving Method and Laser Particle Size

The particle size of the terrigenous clastic rocks is determined by the combination of the sieving method and the laser particle size method,in order to ensure the concerted synergy between the sieve method and the laser particle size method,the analytical data of the laser particle size method is corrected,comparing the probability cumulative frequency curve of sediment rocks before correction and after correction in different geological ages,it is found that the corrected curve can make better characterize the particle size distribution of terrigenous clastic rock. The L9( 34) orthogonal optimization scheme is carried out for the three factorsof the sampler stirring speed( A),pump speed( B) and ultrasonic intensity( C)which influenced the background measurement of the Malvern MS 2000 laser particle size analyzer, The optimal measurement conditions are: A is 600 r/min,B is 2 000 r/min,which makes the background measurement stable,and concluding that the influence degree on the background measurement can be expressed by B > A > error > C. The particle size standard curve is calibrated with 9 reference materials,the residual error between the standard curve of the particle size and the standard curve of instrument was small,ranging from 0. 795% to 2. 934%,the relative standard deviation is between 0. 24% and 0. 33%. This method is suitable for the particle size analysis of terrestrial clastic rocks in various geological ages.