||An integrated stratigraphy around the Plio-Pleistocene boundary in the Chikura Group, the Boso Peninsula, central Japan, based on data from paleomagnetic, oxygen isotopic and widespread tephra correlation
Tamura, Itoko ,
Okada, MakotoMizuno, Kiyohide
Geographical Reports of Tokyo Metropolitan University
52 , 2016 , Department of Geography, Tokyo Metropolitan University
As widespread tephra is considered to have been deposited widely in an extremely short time after volcanic eruption, it has an important role as a useful geological time index. To improve the accuracy of tephrochronology, we propose a widespread tephra correlation based on various characteristics of the tephra layers for the middle section of the Chikura Group from the southernmost part of the Boso Peninsula, Japan, with a refined chronorostratigraphy based on magnetostratigraphy and oxygen isotopic stratigraphic analysis of benthic foraminifers. Around the Plio-Pleistocene boundary, we were able to compare seven tephra layers with the other tephra layers in Plio-Pleistocene strata in central Japan, and were able to obtain a detailed tephrochronology. The improved accuracy of the integrated tephrochronology is expected to contribute to the understanding of environmental changes over time.