Biomineralization Within Vesicles: The Calcite of Coccoliths

198 Young & HenriksenFigure 5. Coccolithus pelagicus and Oolithotus fragilis atomic force microscopy images. (A) AFM imageof a complete C. pelagicus coccolith. Compare with Figure 4C, oblique stripes extending beyond thecoccolith edge are tip artifacts. (B) Ultra high resolution AFM image from a large distal shield element,showing atomic pattern and demonstrating that rhombic faces are developed. A surface unit cell is shown,dashed line gives direction of atomic rows. (C−D) AFM images of complete O. fragilis coccolith and highresolution image from outer edge of coccolith showing atomic pattern and demonstrating that rhombicfaces are developed. (E) Interpretation of relationship of faces developed on C. pelagicus distal shieldelements (grey) to calcite rhomb. N.B. The element represented corresponds to those at bottom left of thespecimen in A. (F) Interpretation of relationship of faces developed on O. fragilis distal shield elements(grey) to calcite rhomb; N.B. The element represented corresponds to those at bottom centre of thespecimen in A, the pale grey portion of the element is a stepped surface. (B) and (D) have been correctedfor distortion following the method in Henriksen et al 2002.