激光-筛分联合法粒度分析结...及粒度端元的沉积动力学意义_唐雯雯.pdf

4期http:/激光-筛分联合法粒度分析结果的表达及粒度端元的沉积动力学意义唐雯雯1，陈奇1，朱永兰1，蔡廷禄2,3，贾建军1,3（1.华东师范大学河口海岸学国家重点实验室，上海200241；2.自然资源部第二海洋研究所海岸带与海岛研究中心，浙江杭州310012；3.浙江省海洋科学院自然资源部海洋空间资源管理技术重点实验室，浙江杭州310012）摘要：河口海岸沉积动力环境复杂，沉积物粗细组分皆有。对于粗细混杂（同时含有砂砾质和泥质成分）的沉积物样品，单一的粒度分析方法不能覆盖整个粒度分布范围，常采用激光-筛分联合法进行粒度分析。由于两种方法的分析原理不同，经常出现细部的激光法结果与粗部的筛分结果部分重合现象，这会影响整个样品的粒度分布计算。石油天然气行业标准碎屑岩粒度分析方法（SY/T 5434-2018）对此问题给出了新的解决方案，但是只有文字描述，没有可操作的计算方法。本研究根据该行业标准提出的方案，推算出激光-筛分联合法粒度分析结果的修正计算公式。以浙江舟山群岛潮间带197个粗细混杂样品为例，采用激光-筛分联合法进行了粒度分析，分别采用直接拼接算法及SY/T 5434-2018算法计算了粒度分布，在此基础上对两套算法所得组分含量和粒度参数进行了比较。结果表明，SY/T 5434-2018算法相较于直接拼接算法，扩大了粗颗粒的体积百分比，减少了细颗粒的体积百分比。两种算法得到的组分含量具有显著的线性相关关系，且砾、砂、粉砂、黏土等组分含量的差异从粗到细依次减少。用两种算法的结果分别计算粒度参数，同样具有显著的线性相关关系，且平均粒径、分选系数、偏度与峰态等粒度参数的差异渐次减小。两种算法得到的组分数据的相似度整体优于粒度参数的相似度，均具有高度一致性，可根据工作需求选择适合的算法，无须对两种算法之间的误差再作验证。借助粒度端元分解模型，将舟山潮间带的沉积物划分出不同的粒度端元，其中泥质端元主要是长江泥沙向浙闽沿岸输送的产物；而砾和砂的成分，多是当地物源或当地波浪分选的结果。关键词：粒度分析；激光-筛分联合法；粒度参数；端元分解；舟山群岛；潮间带中图分类号：P736.21文献识别码：A文章编号：1001-6932(2023)04-0361-14Doi:10.11840/j.issn.1001-6392.2023.04.001收稿日期：2022-07-18；修订日期：2022-10-18基金项目：国家自然科学基金（41876092）；自然资源部海洋空间资源管理技术重点实验室开放课题（KF-2021-104）作者简介：唐雯雯（1999），硕士研究生，主要从事动力沉积与沉积地貌研究，电子邮箱：通信作者：蔡廷禄，博士，高级工程师，电子邮箱：；贾建军，博士，研究员，电子邮箱：Expression of particle size analysis results by laser-sieving combinedmethod and the sedimentary dynamic significance of grain sizeendmembersTANG Wenwen1,CHEN Qi1,ZHU Yonglan1,CAI Tinglu2,3,JIA Jianjun1,3（1.State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China;2.Second Institute of Oceanography,MNR,Hangzhou 310012,China;3.Key Laboratory of Ocean Space ResourceManagement Technology,MNR,Hangzhou 310012,China）Abstract:The estuarine and coastal sedimentary dynamic environment is complex,and the sediments have both coarse andfine components.For sediment samples with mixed coarseness and fineness(containing both sand-gravel and argillaceouscomponents),a single particle size analysis method cannot cover the entire particle size distribution range,and the laser-sievingcombined method is often used for particle size analysis.Due to the different analysis principles of the two methods,the results海洋通报MARINE SCIENCE BULLETIN第42卷第4期2023年8月Vol.42,No.4Aug.202342卷海洋通报http:/of the laser method for the fine parts often overlap with the sieving results of the coarse parts,which brings challenges to thecalculation of the particle size distribution of the entire sample.The petroleum and natural gas industry standard Analysismethod for particle size of clastic rocks (SY/T 5434-2018-2018)provides a new solution to this problem,but there is onlytext description and no operational calculation method.In this study,according to the scheme proposed by SY/T 5434-2018-2018,the revised calculation formula of the particle size analysis results of the laser-sieving combined method was calculated.Taking 197 coarse and fine mixed samples in the intertidal zone of Zhoushan Archipelago in Zhejiang Province as an example,the particle size analysis was carried out by the laser-sieving combined method,and the particle size distribution was calculatedby the direct splicing algorithm and the SY/T 5434-2018 algorithm respectively.On this basis,the component content andparticle size parameters obtained by the two algorithms were compared.The results show that compared with the direct splicingalgorithm,the SY/T 5434-2018 algorithm enlarges the volume percentage of coarse particles and reduces the volume percentageof fine particles.The components content obtained by the two algorithms has a significant linear correlation,and the differencein the content of gravel,sand,silt and clay decreases from coarse to fine.The particle size parameters were calculated with theresults of the two algorithms,which also had a significant linear correlation,and the difference in particle size parameters suchas average particle size,sorting coefficient,skewness and kurtosis gradually decreased.The similarity of the component dataobtained by the two algorithms is generally better than the similarity of the particle size parameters,but both of them are highlyconsistent.The suitable algorithm can be selected according to the work demand,and the error between the two algorithms neednot be verified again.With the aid of the grain-size endmember decomposition model,the sediments in the intertidal zone ofZhoushan are divided into different grain-size endmembers,in which the argillaceous endmember is mainly the product of theYangtze River sediment transportation to the coast of Zhejiang and Fujian.The composition of gravel and sand is mostly theresult of local provenance or local wave sorting.Keywords:particle size analysis;laser-sieving combined method;particle size parameters;endmember decomposition;Zhoushan Archipelago;intertidal zone海岸沉积物主要指分布在海滩和潮滩的岩石、矿物及生物骨骼和壳体等碎屑1。粒度分析是获得这些沉积物碎屑的颗粒大小和各粒级的分布状况的一种沉积学分析方法2。粒度分析结果主要包括砾、砂、粉砂和黏土等组分含量，可以用于划定沉积物类型，还可以用来计算平均粒径、分选系数、偏态和峰态等粒度参数。粒度分析的结果是重要而基础的沉积学资料，可用来解释沉积物输运的水动力条件3-5及沉积环境特征6-9。粒度分析的方法有很多，如直接测量法、筛分法、沉降法、激光法、图像法等。不同方法的原理不同，适用范围也有差别。筛分法适用于分离粒径大于0.063 mm