The Geology at the Naze can appear to be quite complicated, But think of the cliff as a book, when you are looking at them you are reading 53.7 Million years of Earths history.

At the base of the cliffs extending out on to the wave cut platform, (foreshore) is the Bluish grey London Clay so called
because it is found throughout the London basin from the North Kent coast right the way up to South Suffolk.

The London clay was laid down in the delta of a large river in a sub tropical climate to the east of a large landmass, this is thought to have been some 250-300 Kilometres to the south west of the modern shoreline.

The clay is extremely fossiliferous containing many fossils of marine origin, the commonest of these are the teeth of the Seven gilled sand Shark (Striatolamia macrota), also occasionally are the larger teeth of the fossil Mackerel Shark (Otodus obliquus). It also contains much plant material derived from rafts of material drifting out to sea from the heavily forested mainland, this is nearly all preserved as Iron Pyrites (Ferrous Disulphide)

Sitting directly on top of the London clay is the Waltonian sub-stage of the late Pliocene early Pleistocene  Red Crag.
This is much younger than the underlying clay being a mere 1.8 - 2 Million Years old, all the strata between the clay and the Crag being removed by Glacial action in the intervening period.

The Red crag is the colour it is because of the Iron Pyrite in the underlying clay when eroded out and weathered 2 million years ago formed Ferrous sulphate which turned the sand and Shells of the Crag the brilliant orange colour they are today.

The Crag can be separated into two distinct layers, first comes the Red Crag Basement or Nodule bed this lays directly on the planed upper surface of the clay which in some areas is covered with the burrows of fossil invertebrates now in filled with the spherical crystals of Glauconite a green coloured mineral. There is some argument about the exact age of this Basement bed some authorities saying it could be 5 Million years in age, that is Miocene, which would give the Naze the only Miocene rocks in Great Britain. This bed contains examples of Mineralised Bone mostly of Cetacea.

Next comes the Red Crag proper, this consists of a sandy matrix with many partially decalcified and Broken shells the
commonest being those of the Bivalve Glycymeris glycymeris, the common Dog cockle, the other shell the crag is well known for is the Neptunia contraria or Left handed whelk. It is thought the Red crag was laid down as a sandbank to the  East of a large landmass.  Next page