Septarian nodule

This is a concretion of rock, formed from a calcium-rich clay that hardened into a limestone nodule. Later, the rock shrank, creating cracks that were then filled with water in which calcite crystal formed. The angular cracks are called septaria which comes from the Greek word ‘septum’ meaning partition.

Find out more on the rocks and pseudofossils page.

Common name

Septarian nodule

Type

Rocks and Pseudofossils


Strata

Oxford Clay, Red Nodule Beds

Time period

Upper Jurassic

Age

160 million years

Where found

Furzy Cliff

Found by

Unknown

Museum

Dorset County Museum, Dorchester

Accession number

DCM.G.04151