Sr, Nd, Pb, and Hf isotopic compositions and verification of isotope zone classification from Ashio, Asahi, and Abukuma Belts, southern part of the NE Japan Arc

Abstract

The Cretaceous to Paleogene plutonic rocks are widely distributed as a basement rock of the NE Japan Arc. In this report, newly obtained Sr, Nd, Pb, and Hf isotopic composition are reported, and comparison and verification with a geotectonic division and isotope zone division are performed. The epsilon Nd-Sr (0Ma) diagram, the domain of the Abukuma Belt and the Ashio Belt is distinguished clearly. The epsilon Hf-Nd diagram shows the narrow extent, and the Abukuma and the Ashio Belts are distinguished more clearly. Re-classification of isotope zone by Hf isotope may possibly.