U-Pb Geochronology from five volcanic tuffs from the Yezo Group, Hokkaido, Japan

The dataset contains 206Pb/238U zircon CA-ID-TIMS dates from five volcanic tuffs from the Yezo Group, Hokkaido, Japan. The data underpin an age model developed for a proto-Pacific seawater 187Os/188Os spanning the Cenomanian-Turonian boundary interval, and Ocean Anoxic Event 2. The resulting age model supports the integration of the Pacific 187Os/188Os dataset with similar records from the Western Interior Seaway.