R4: Mineral sciences of the Earth surface

[R4-06] Relationship between morphology and crystal orientation in coccoliths analyzed by EBSD

*Toshihiro Kogure¹, Masayuki Utsunomiya² (1. Univ. Tokyo Sci., 2. GSJ, AIST)

Keywords:coccolith, calcite, crystal orientation, EBSD

We applied electron back-scattered diffraction (EBSD) with high-resolution scanning electron microscopy (SEM) to placolith-type hetero coccoliths of Umbilicosphaera species including extinct and extant ones. It was found that extant U. sibogae and U. foliosa have similar crystal orientation of calcite (V-unit) forming the distal shield but extinct U. patera which is considered as their most recent ancestor definitely has different orientation.