Identification of the source caldera for the Middle Miocene ash‐flow tuffs in the Kii Peninsula based on apatite trace‐element composition

Abstract A large caldera cluster consisting of at least four calderas (Omine, Odai, Kumano‐North and Kumano calderas) existed in the central–southern part Kii Peninsula approximately 14–15 Ma. On other hand, thick Middle Miocene ash‐flow tuffs, referred to as Muro Ash‐flow Tuff Sekibutsu Member, are distributed northern Peninsula. Although these tuffs considered have erupted from central‐southern Peninsula, identifying source has been controversial because similarities petrological characteristics identical radiometric ages volcaniclastic rocks calderas. We successfully discriminated eruptive products each based on apatite trace‐element compositions pyroclastic dikes also demonstrated that lower main Member was Odai Caldera, which is located central Our findings show possible correlations among conduits caldera‐fill and/or outflow deposits, even cases where they densely welded diagenetically altered. This method useful for study deeply eroded ancient