[MIS19-P07] Reconstruction of the surface water mass fluctuation during the late Pliocene to early Pleistocene based on planktonic foraminiferal fossils from the Mera Formation, Chikura Group, in the southernmost part of the Boso Peninsula
Keywords:Planktonic foraminiferal assemblages, Chikura Group, Northern Hemisphere Glaciation
PhaseⅡ (2.75-2.65Ma): Transitional water species increased up to 50%. It was a cold environment where the influence of mixed water was strong.
PhaseⅤ (2.42-2.35Ma): Kuroshio species increased up to 40%, which is the highest value in this study
PhaseⅥ (2.35Ma~):Transitional water species increased to about 50% while repeating amplitude. Therefore, cooling was gradually strengthened in this phase.
Cooling did not proceed unilaterally after 2.7Ma, it occurs again from 2.35Ma after the period when the influence of Kuroshio became temporarily stronger. In addition the glacial-interglacial cycles seem to be affecting composition of planktonic foraminiferal assemblages.