Fossil Friday Ammonite

You never know what you might find! Here we have a chalk ammonite. Calcareous ooze filled up a hollow left by this Nautiloid-like mollusc at the bottom of the warm shallow sea that covered Southern England about 90 million years ago.

The ammonite was found whilst carrying out Saturation Moisture Content of Chalk testing, a common test when Chalk is used as an Earthworks Material. The samples themselves were obtained when Trial-Pitting near Bignor, West Sussex. The geology is probably New Pit Chalk Formation (formerly part of the Middle Chalk Formation) formed in the Cretaceous Period and mainly consists of the microscopic remains of plankton, especially the disc shaped calcite plates or coccoliths that make up the spherical coccolithophores.