Unraveling the formation process of Holocene carbonate concretions through ¹⁴C analysis

Abstract

The formation process of carbonate concretions might involve the supply of organic matter from organisms, but the detailed early stages of this process remain unclear. Therefore, our research has focused on determining how long it takes for carbonate concretions to form after the death of organisms. We conducted radiocarbon dating on biogenic remains from carbonate concretion samples collected from the fluvial deposits around Nagoya Port (Minami et al., 2022). The results showed that both had approximately the same age (8000-7800 cal BP), suggesting that these samples rapidly concretized and formed after the death of organisms. In this study, we applied the same methodology used for Nagoya Port concretions to the concretion samples collected from Shimizu Port. By summarizing the results obtained from both concretions, we aim to explore the formation process of carbonate concretions.