R1: Characterization and description of minerals (Joint Session with The Gemmological Society of Japan)

[R1P-05] Mineralogical study on zeolites in gastropod fossils in Miocene sediments in Minamisoma , Fukushima , Japan

[Presentation award entry]

*Atsushi ISHIHARA¹, Hiroaki Ohfuji¹ (1. Sci. Tohoku Univ. )

Keywords:zeolite, heulandite, mineralized fossil

To understand origin and formation processof zeolites in gastropod fossils in Miocene sediments in Minamisoma , Fukushima , Japan , we investigated the mineralogical characteristics of them. Our observation suggests two important factors in the zeolite formation inside the fossils: 1) the shells provided a (semi-)closed environment in which fluid was retained over a long time period, and 2) diagenesis provided suitable temperature conditions for the formation of zeolite.