Septarian nodule

These concretions formed from a calcium-rich clay that hardened into the round limestone nodule. Later, the rock shrank, creating cracks that were then filled with water in which calcite crystal formed. They are almost certainly from the Kimmeridge Clay and could have been collected along the Portland Harbour Shore.

Find out more on the rocks and pseudofossils page.

Common name

Septarian nodule

Type

Rocks and Pseudofossils


Strata

Unknown

Time period

Upper Jurassic

Age

Unknown

Where found

Unknown

Found by

Unknown

Museum

Portland Museum

Accession number

POLPM.T1013