Abstract

In order to explore the change of biogenic Ba content in Pacific Ferromanganese crusts and their relationship with paleoproductivity fluctuations, a thick crust CHA99 from the Magellan Seamounts (MST) has been approached in detail. Studies show the variations of Babio(Ba/Al), AR Babio (Ba/Al), and Ba/Al ratio, which are related to the biogeochemical processes, are found to exhibit similar rhythmical evolution trend and the variations of Ni, Zn, Cu and Mo content exhibit the same rhythmical change since 60Ma. Studies find that Babio(Ba/Al), AR Babio(Ba/Al), and Ba/Al ratio exhibit undulate change from begin until almost the lowest value at ca. 36.8Ma and then keep vibration in the last ca.36.8Ma. The obvious change in 34-38Ma is basically consistent with the significant changes in δ18O, δ13C and sealevel (m) value in 34Ma-38Ma (cooling E/O). The preliminary result reveals that climate cooling causes the decrease of Babio(Ba/Al), AR Babio (Ba/Al), and Ba/Al ratio. Paleoproductivity fluctuations is mainly related to the change of paleoclimate, perhaps also related to the drift of Pacific plate, abrupt events or CAEs etc. The change of biogenic Ba content in Pacific Ferromanganese crusts probably can be regarded as a signal of paleoproductivity pulses.

This content is only available via PDF.
You can access this article if you purchase or spend a download.