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地球学报 2002
The Effects of Marine Phospharization on Element Concentration of Cobalt-rich Crusts
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Abstract:
The phospharization related closely to marine cobalt rich crusts has been studied in detail. Sampling from top to bottom of a 10 cm thick sample dredged from Magellan seamount, NW Pacific, was conducted at an interval of 5 mm. The concentrations of ore forming and rare earth elements in 20 subsamples were determined. The results show that an obvious difference exists between the new unphospharized crusts and the old phospharized crusts. Fe, Mn, Si, Al, Zn, Mg, Co, Ni, Cu are depleted while Ca, P, Sr, Ba, Pb are enriched in old crusts. The order of depletion and enrichment is Co>Ni>Mg>Al>Mn>Si>Cu>Zn>Fe and P>Ca>Ba>Pb>Sr respectively. It can be concluded that the intensity of phospharization controls the concentration variation of ore forming elements in crusts and causes the loss of Co, Ni and other main ore forming elements.The phospharization also affects the abundance of REE in crusts. The abundance of REE and the content of Ce in old crusts are higher than those in younger crusts. The patterns and fractional distillation characteristics of REE in new and old crusts have not changed fundamentally. Y positive anomaly in old crusts has no relation with the phospharization. The research on phospharization of crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources.
