GEOCHEMICAL TYPES OF PACIFIC POLYMETALLIC NODULES - AN APPLICATION OFMULTIVARIATE-ANALYSIS

A total of 843 samples of Pacific Ocean polymetallic nodules (PNs) fro m five survey areas have been studied (metals analyzed: Mn, Fe, Ni, Cu , Co, Zn, Pb). The statistical analysis included the following techniq ues: factor R analysis, quick cluster Q analysis into 50 preclasses, v arious hierarchical cluster Q analyses (HCAs) using the preclasses (ap plication of different HCAs to an identical set of data and of an iden tical HCA to two different subsets of the data), comparison of the HCA . The PNs of the sun,ey areas can be grouped into five geochemical typ es (I-V). The genesis of the PNs was interpreted as early diagenetic, hydrogenetic, and mixed (early diagenetic/hydrogenetic and hydrogeneti c/hydrothermal). In addition, some further conclusions regarding the a pplicability of various HCA techniques depending on the structure of t he data set have been drawn.