THE ELEMENT ASSOCIATION CHARACTERISTICS AND GEOLOGICAL SIGNIFICANCE OF DEEP-SEA SEDIMENTS IN THE CENTRAL PACIFIC OCEAN

The deep sea sediments which are rich in rare earth elements and yttrium, (REY, including Y) may become a potential mineral resource in the Ocean in addition to polymetallic nodules, cobalt-rich crusts and hydrothermal sulfides. The major and trace elements for 46 samples of REY-rich sediments (∑REY=(730-1 596)×10^-6) and 53 samples with relatively poor REY (∑REY=(324-487)×10^-6) from the Central Pacific Ocean were analyzed. The groups of elemental associations and four main factors were defined respectively by using cluster analysis and factor analysis. The geochemical characters and elemental associations of these sediments suggest that the REY contents depend on the P contents for both the two types of sediments. However, the sediments came from different sources and deposited in different time. The aluminum silicate (clay minerals and zeolites) plays more important role for the concentration of REY in the REY-rich sediments but less significant role in the REY-poor sediments.