Late Permian to Early Triassic environmental changes in the Panthalassic Ocean: Record from the seamount-associated deep-marine siliceous rocks, central Japan

► We present geochemical property of Panthalassic deep-marine PTB siliceous rocks. ► End-Permian sudden onset of anoxia caused mass extinction of Permian radiolarians. ► δ13Corg values exhibit stepwise drop across PTB transition. ► Anoxia persisted into early Early Triassic, but was intermittently weakened. ► Panthalassa Ocean was relatively hospitable, favored by early biotic recovery.