沉积物物源组成的定量判识方法及其在冲绳海槽的应用

METHOD OF ESTIMATING SEDIMENTARY END-MEMBERS AND ITS APPLICATION TO OKINAWA TROUGH REGION

用多元成分数据统计分析中的端元估计算法，处理混合源沉积物地球化学数据，定量判识沉积物物源端元的化学成分和比例。将该方法应用于已知端元的人工数据，端元的化学成分和含量的估计值与已知值非常接近。实验结果说明，这种成分数据分析算法是定量判识沉积物物源端元的有效方法。用此方法处理冲绳海槽中段表层沉积物地球化学数据集，成功地定量估计出陆源物质、火山源物质和生物源物质的平均化学成分；同时定量计算出该区底质沉积物中陆源物质、火山源物质和生物源物质的百分含量。最后，将实算结果与矿物学判识的物源分布进行对比，二者总趋势一致，前者的局部变化大。此方法用于物源组成的定量估计工作，既经济又快速。

The method of composition data analysis used in estimating origin end-members fromsubmarine sediment is introduced here. The method is demonstrated for known end-membersartificial data; the estimated error between known and estimated proportion of end-members is 7.8%,correlation coefficient between the known and estimated end-members is close to l, and theircompositions are almost the same. These results have shown that the method is efficient ineshmahng end-members from submarine sedimentary samples. Further, the method is used forsubmdrine sedimentary datasets of the Okinawa Trough Region. Three origin end-members areidenhfied from the datasets successfully. These extimated endmembers (Tab.7) represent continental,biologic and volcani corigin composition, respechvely. Geochemical characters of the continentalendmembers are that S iO2, Al 2 O3, Ti O2, S r, Zr, Hf and REE are high, and Cao and CO2 are low inabundance; the biologic end-member has characters of high CaO and CO2 and low SiO2 and Al2O3in abundance; the volcanic endmember is characterised by high Cu Co, Ni, S and Cr contents.Estimated proportion range of continental, biologic and volcanic end members are 20.3%- 81.2%,3.6%-64.9% and 1.7%-38.1%, respechvely. Eshmated distribuhon figures of these end-membersare presented (Fig. 1, Fig.2,Fig.3) in this paper too. The clistribuhon of eshmated endmembers arecomped with that obtained by edhonal method- petrology and Anneralogy method; they aresimilar in the mass, but the former connins more detail. The method is also adaptable for petrology,pedology and water pollution studies.