The Kalkowsky Project - Chapter VI. A panorama of synsedimentary broken ooids

Abstract

Broken ooids are known to occur in both aragonitic and calcitic ooids with radial fabrics. In the literature, it has been suggested that synsedimentary breakage could be related to attrition/mechanical impacts, hypersalinity, or desiccation. However, this paper demonstrates that none of the aforementioned phenomena provides a valid explanation. Although the exact process remains unknown (potentially involving some synsedimentary recrystallization), it is shown that: 1) the breakage is genetically linked to the radial fabrics; 2) the ratio of ooid breakages increases with the relative thickness of the radial cortical layers; 3) fracture growth in broken ooids proceeds centripetally.