Micron scale investigation of marine ores by nuclear microprobe technology

Abstract The marine mineral deposits are often growing slowly with rates of few millimeters per million years. Their geochemical signatures provide clues to the marine mineral genesis, their growing processes and the geological environmental variations. The ability of microscopic quantitative analysis of total elements brought the nuclear microprobe a potentiality for revealing the deep-sea historical information, which has been concealed in marine ores for million years, more attentively and directly. Four kinds of marine ores have been investigated with the nuclear microprobes. They are oceanic needles, deep-sea ferromanganese nodules, seamount ferromanganese crusts and radioralia microfossils. In order to meet the various formations of marine ores, three data acquisition models, spot analysis, line scan and mask accumulation, were used. A zooming technique was applied to locate a focused beam exactly at an interesting area in micron scales. By means of GEO-PIXE we got all results quantitatively. The reliability of the results was tested by measuring three manganese nodule standards.