AUTHOR=Ito Hisatoshi TITLE=Quaternary caldera-forming eruptions at the Sanzugawa caldera, NE Japan, revealed by zircon U-Pb geochronology JOURNAL=Frontiers in Earth Science VOLUME=10 YEAR=2023 URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.964773 DOI=10.3389/feart.2022.964773 ISSN=2296-6463 ABSTRACT=

Recent application of zircon U-Pb geochronology has contributed to deciphering the evolution of caldera systems worldwide. However, in the Tohoku region, NE Japan, this is not the case, although it is well studied as a typical island arc subduction system. Here, U-Pb dating of zircon suggests that the Sanzugawa caldera, the largest caldera in Tohoku since late Miocene, initiated its caldera-forming volcanic activity at ∼7 Ma and culminated its activity in late Pliocene to Quaternary (3.0–1.5 Ma). This is contrary to a previous notion that the caldera developed in late Miocene to Pliocene (6–3 Ma) based on mainly whole-rock K-Ar dating results. This finding may also question a current hypothesis of relatively subdued volcanism at 3.5–1.5 Ma in NE Japan and thus shows the need to date other calderas in the Tohoku region with zircon U-Pb and/or Ar-Ar methods to better understand the magmatic history of this region.