Marne in Turitella

Mixed sedimentary rock consisting of a mixture of limestone and clay.
When the limestone content increases in clayey rocks, we move successively to marly clays (15% limestone), marls, calcareous marls and marly limestones (70% limestone).
The model presented contains Turitella which are gastropods that appeared in the Cretaceous, last period of the Mesozoic (140 million years ago).