CHARACTERISTICS OF THE ELEMENT GEOCHEMISTRY OF THE SUSPENDED MATTER IN THE CHINESE CONTRACT AREA, NORTHEAST PACIFIC OCEAN

The elemental components of the suspended matter samples collected from different layers in the water column at 3 stations in the Chinese Contract Area, Northeast Pacific Ocean, were analyzed by ICPMS. The content of the 12 elements (including Na, Mg, Al, Ca, Ti, Mn, Fe, Co, Cu, Sr, Ba and Pb) of the suspended matter ranges from several hundreds to less than 0.01 μg/dm³ as the content of total suspended matter (TSM) in the water column was less than 0.30 mg/dm³ in general. The concentrations of suspended matter and the 12 elements in the upper layer of 500 m are higher than that in the mediate layer from 500 to 5 000 m of the water depth with minor fluctuations. However, sharp fluctuation of the concen-trations of the suspended matter and 12 elements was found in the lower layer>5 000 m of the water depth in the water column. Among the 12 elements, Al and Ti mainly originated from terrigenous particles; Sr and Ba mainly originated from marine autogenic particles and Pb was mainly related with anthropic activi-ty, respectively, resulting from their geochemical characteristics. According to correlation analysis of the 12 elements, Na, Mg and Ca mainly originated from marine autogenic particles,similar to Sr and Bio-Ba; otherwise, Mn, Fe, Co and Cu mostly came from terrigenous particles in the western part. In the eastern part, the concentration of Na, Mg and Cu showed multi-sources characteristics, while the sources of Ca, Mn, Fe and Co were the same as those of Al and Ti. The materials source and its amount of supply were the controlling factors for the concentration and distribution of the TSM and its element compositions in the water column at different stations. Relatively abundant supply of volcanic matter, caused by relatively strong seafloor volcanic eruption in the western part of study area,was a direct factor to conduce to the diverse distribution of the same elements at different stations.