AMS radiocarbon ages of Holocene tephras from Iraya Volcano in the northern Philippines

Abstract Iraya Volcano, situated at the northern tip of Batan Island in the Batanes group, marks the northernmost extent of the Philippine archipelago. Aside from the presence of accessible tephra deposits, the numerous archaeological sites on the island provide key insight into tephrochronology and volcanic hazard assessment. This paper presents stratigraphy and 21 radiocarbon ages of Holocene tephra layers distributed on the island. The eruption ages of the Holocene tephra are approximately 12.4 cal ka BP for Rolling Hills at the bottom, 4.5–4.9 cal ka BP for San Antonio, 2.1–2.5 cal ka BP for Mahatao, 1.6 cal ka BP for Basco, and 1.2–1.6 cal ka BP for Boulder Beach, with most of the tephra concentrated in the latter half of the Holocene. Artifacts excavated from Reydante Cabizon Property Site, San Antonio, Basco can be thought to date to around 4 to 2 cal ka BP, which is consistent with tephrochronology.