Fig. 6

The texture and crystal co-orientation strength of A. lobifera shell calcite. (A): Sample contaminated with Cd²⁺; (B): sample contaminated with Pb²⁺. Measurements 7 and 8 are taken on poisoned shell sections. As the pole figures show, we find for all measurements an axial texture for shell calcite. For all EBSD scans calcite c-axis is perpendicular to outer shell surface and rotates with the curvature of the shell. There is no difference in type of texture or calcite c-axis orientation between chambers secreted in a natural environment and chambers secreted in polluted water. Crystal co-orientation strength is quite increased, see MUD values in (A), (B). We find for A. lobifera a higher crystal co-orientation strength, relative to that for A. lessonii; compare MUD values of Figs. 5 and 6.