Spherical concretion associated with tusk shell
Spherical concretion with a tusk shell found instrata of 16 million years ago. It formed very quickly at most several months, mush shorter than previous estimates. Application of the fast formation of concretion is now investigated.
KEYWORDS: Spherical concretion / Calcite / Sealing / Applied geoscience
Department of Earth and Planetary Sciences
Reference
https://www.sci.nagoya-u.ac.jp/images/kouhou/30.pdf
(Japanese only)