There lies beneath Norfolk a platform of very ancient rock. In some places, this rock is about 1,000 metres below the surface and is similar to surface rock found in Wales and the Pennines, but, in Norfolk, this is overlaid by sediments which have accumulated over millions of years.

The most extensive sediment is the chalk; in fact, virtually the whole of Norfolk is under laid by chalk with the associated flint, in some places to a great depth. This means that during the Cretaceous Period, 190 to 136 million years ago, Norfolk was at the bottom of the sea.

On top of the chalk bed there are several other deposits of material caused by, at least, four Ice Ages. For example the last ice age, which reached its maximum extent 18,000 years ago and retreated about 10,000 years ago, is believed to have deposited the sand and gravel forming Salthouse and Kelling Heaths, where evidence has been found of Mesolithic Man.

In the (old) Sharrington Parish, which stretched north to the boundary with Saxlingham, there are found three types of earth.

1. The northeast corner of the parish is part of the Cromer Ridge, where a thin loam covers sand and gravel.
2. The eastern edge of the parish is touched by a Chalk Scarp, where the dirty white chalk is very close to the surface.
3. In the rest of Sharrington, that is, the main part of the village and parish, the chalk bed is covered by the “Boulder Clay” as is much of central Norfolk. This is a stiff grey glacial deposit, rich in chalk stones, the flint. This clay subsoil is impermeable and supports a “Perched Water table”, that is, the water cannot drain through the clay to the chalk. Therefore it is higher and nearer to the surface than it would have been had not an Ice Age glacier deposited the boulder clay.

The most common top soil is dark, flinty and sandy Clay Loam.

During the Ice Ages, the land periodically rose and fell raising and lowering the sea levels. At one point after the last Ice Age, the southern part of the North Sea was converted into land, thereby joining Norfolk to Continental Europe and the so called “Maglemose” people migrated from Denmark into Eastern England. A Maglemosian settlement has been found at Kelling Heath.

Also, fossils of Sabre Tooth Tiger, Elephant and Hippopotamus have been found in the Cromer area, showing that the climate had been much warmer at some time.

By Peter Chapman 2000

Source References :

(i) “An Historical Atlas of Norfolk” Published by the Norfolk Museums Service. 2^nd edition.

(ii) “British regional Geology. East Anglia”. 4^th edition. Her Majesty’s Stationery Office.