基于聚类分析的莱州湾晚第四纪介形虫群落结构研究

Clustering Analysis of Late Quaternary Ostracod Community Structure in Laizhou Bay

为深入探讨渤海莱州湾晚第四纪介形虫的群落结构多样性特征,通过对渤海莱州湾GK138孔、GK111孔、GK95孔、GK59孔、GK74孔、GK79孔和GK89孔中介形虫化石样本的实验处理和数据统计,结合Q型聚类及主成分分析对钻孔中介形虫的群落结构进行属种数据分析。结果显示,研究区内介形虫群落可以划分出3组代表不同沉积环境的化石组合,第I化石组合带主要以Sinopontocythere subjaponica、Loxoconcha ocellata和Limnocythere dectyophora等为优势种,沉积环境为潮上带-潮间带环境;第Ⅱ化石组合主要以Bicornucythere bisanensis、Pistocythereis bradyformis和Neomonoceratina dongtaiensis等海相种组合为优势种,沉积环境潮间带至潮下带环境;第III化石组合带主要以Candoniella albicans为优势种,沉积环境为河流漫滩至潮上带环境。

To make an in-depth exploration into the community structure characteristics of ostracods in Laizhou bay during the late Quaternary,samples were taken from boreholes GK138,GK111,GK95,GK59,GK74,GK79 and GK89for experiment treatment and data statistics.Genus-species analyses were made of the community structure characteristics of ostracods in these boreholes by using Q-mode clustering analysis and principal component analysis.The results show that the ostracod communities in the study areas can be categorized into three microfossil assemblages representing different sedimentary environments.Assemblage I,with Sinopontocythere subjaponica,Loxoconcha ocellata and Limnocythere dectyophora as the dominant species,represents the supratidal-intertidal sedimentary environment;Assemblage II,with Bicornucythere bisanensis,Pistocythereis bradyformis and Neomonoceratina dongtaiensis as the dominant species,represents the intertidal-subtidal sedimentary environment;and Assemblage III,with Ammonia beccarii as the dominant species,represents the flood plain or the supratidal sedimentary environment.