Abstract:

The eolian deposition is one useful index to know the climate change of source region and the atmospheric cycle model at that time. The eolian records indicated by Al fluxes in the low-latitude ferromanganese crusts are determined by the high-revolution microprobe technique. The results show that the average content of Al fluxes in the ferromanganese crusts during the past 70 Ma is 300.5  μg/(cm²·ka), which has recorded the incompleteness of eolian history in the southern hemisphere and the northern hemisphere. From the Late Cretaceous to the Late Miocene period, the M06 ferromanganese crust lay in the southern of the intertropical convergence zone, and its’ Al fluxes recorded the eolian deposition from the episodic volcanism in the southern hemisphere. Since the Late Miocene period, the M06 has been controlled by the wind system of the northern hemisphere, and its’ Al fluxes can reflect the change of tectonic and climate in Asian dust source area.

Key words: ferromanganese crust, eolian deposition, Pacific Ocean, low latitude, sedimentation