Overview
- A Tohoku University‑led team published its finding on May 19 in Communications Earth & Environment reporting a sharp spike in platinum‑group elements that they attribute to the K/Pg (asteroid impact) boundary.
- The attribution rests on three lines of evidence: a pronounced enrichment of platinum‑group elements, changes in microfossil assemblages above and below the layer, and tephra ages that match the ~66 million‑year K/Pg horizon.
- The layer was recovered from mudstone in the Nemuro Group near Urahoro in eastern Hokkaido and is the first chemical confirmation of K/Pg impact traces in Japan and the wider Northeast Asia–Northwest Pacific region.
- Field and lab work show the exposed section is fault‑truncated and likely records sediment deposited about 30,000 years after the impact, so the team is conducting follow‑up analyses and searches for continuous pre‑ and post‑impact strata.
- The find gives scientists a distant, high‑latitude data point to test how far the Yucatán impact’s dust, aerosols and climate effects spread and to better resolve regional environmental change and ecosystem recovery after the extinction event.