Paramoudra: observations on large flint structures from the Chalk (Upper Cretaceous) and flint formation

摘要

The primary endeavour of the present paper is to classify the types of paramoudra. The discovery of a Cretaceous sponge reef at West Runton (North Norfolk), with a NE tidal influence noted on the rims of paramoudra and next generation placement across the reef, revealed a benthic origin of these flints. Additional evidence suggests that sponges were the causative organism of paramoudra and the majority of primary flint. Photographic and field observations are presented to organize these curious flint structures into recognizable categories and offer an alternative interpretation of flint formation.