Geochemistry of Molybdenum Element in Co-rich Crusts from the Magellan Seamounts and Tracing of Paleoceanographic Environment

In order to explore the geochemical characteristics of Mo element in Cobalt-rich crusts and their relationship with paleoceanographic environment variation, 56 crust samples and a thick crust from 7 seamounts in the Magellan Seamounts (MST) have been approached in detail. Studies show that the average Mo content of crusts in the area is 444ppm; Mo exhibits a positive correlation with Mn, Ni and Ba with a correlation coefficient of 0.83, 0.79 and 0.52, respectively; a negative correlation with Si, Al and Fe with a correlation coefficient of -0.86, -0.74 and -0.64, respectively. Factor analysis shows that Mo in the MST Cobalt-rich crusts has a close relation with hydrogenous sedimentation and a definite relation with biogeochemical process, but no relation with detritus and Fe phase. Based on the Co chronometer dating, we carry out the research on the relation between Mo content variation and paleoclimate, paleoceanographic phosphogenic events, paleoceanographic redox environment during the growth process of a thick crust. The preliminary results reveal that Mo content would decrease with the climate getting cold; paleoceanographic phosphogenic events cause the loss of Mo content; the change of paleoceanographic redox environment exerts no influence on the variation of Mo content, and Mo dominant species of the incorporation into Cobalt-rich crusts would be relatively simple.