Natural England - Palaeogene Period
Palaeogene Period
Age : 24 to 65 million years ago
Geography, environment and climate
Southern and south-east England were occupied by a shallow sea with estuarine conditions prevailing at times. Terrestrial habitats became more prevalent as time progressed and most of the British Isles was land over this period of time. The nature of the land surface is poorly known but appears to have been subdued with wide plains and large extensive river systems.
The regional climate was warm and similar to that of the sub-tropics of Asia and was characterised by high levels of precipitation and environmental stability. Britain continued its northward migration into cooler latitudes.
Key events
The Palaeogene period is marked by the opening of the North Atlantic, which over the next 50 million years or so had a profound effect on the climatic evolution of the British Isles.
Mammals dominated the land fauna following the extinction of the dinosaurs at the end of the Cretaceous.
Away from the shallow sea occurring over southern England, the land supported dense tropical to sub-tropical and warm-temperate forests, with mangrove swamps on the coasts. The overall character of the recorded fossil flora shows affinities with the present-day Malay Peninsula.
Rock types and occurrence in England
Rocks from this time are represented by the marine clays and sands that occupy the Hampshire Basin and the London Basin. These comprise a series of sands, clays and limestones that outcrop in east Dorset, Hampshire, the Isle of Wight, Berkshire, the wider Thames Valley, Essex and North Kent. These sediments record fluctuating environmental conditions from terrestrial/fluvial through to fully marine. Formations such as the London Clay, the Barton Clay and the Solent Group are very fossiliferous and contain the remains of many groups of animals and plants that are familiar today.