珠江口外陆架表层沉积物的地球化学分区

根据249个表层沉积物样品的Ca,Al,N,P,Mg,Fe,Mn,Ti和有机碳的测定数据,利用稳健RQ型主分量分析及Q型聚类分析方法,对珠江口外陆架表层沉积物进行了地球化学分类,并将该陆架区划分成陆源细碎屑沉积区、经叠加改造的残留泥砂质沉积区、生物碎屑沉积区以及高能环境下的石英砂质沉积区。结果表明了稳健统计方法相对于传统统计方法的优越性,以及采用稳健主分量的Q载荷进行聚类分析相对于用原始变量进行聚类分析的优越性。

THE GEOCHEMICAL ZONATION OF SEA-BOTTOM SEDIMENTS ON THE SHELF OFF PEARL RIVER MOUTH

249 sea-bottom sediment samples taken from the shelf area off Pearl River Mouth were analysed for contents of Ca,Al,N,P, Mg, Fe, Mn, Ti and organic carbon. These geochemical data were statistically analysed using methods of robust RQ-mode principal components analysis and cluster analysis. Four groups of sediment samples with distinct geochemical characteristics were identified. According to the geographic distribution of these groups, the shelf area was divided into four zones different in sedimentary environment, namely the sedimentary zone of terrigenous fine clasts, that of reworked relict clastic deposits, that of bioclasts,and that of high-energy quartz sand. These results demonstrated the advantage of robust statistical methods over the conventional one, and the advantage of using Q-mode loadings in cluster analysis over using raw data.