Geology of Hampshire

Hampshire's geology broadly comprises a major syncline in the Southern England Chalk Formation, surrounding a core of softer Tertiary rocks. This gives rise to two characteristic landscapes, the Hampshire Basin and the Downs.

Hampshire Basin

In the south, along the coast, soft Eocene and Oligocene clays and gravels form low flat terrain, the Hampshire Basin. Protected from sea erosion by the Isle of Purbeck, Dorset, and the Isle of Wight, this land supports heathland and woodland habitats, a large area of which form part of the New Forest. The New Forest has a mosaic of heathland, grassland, coniferous and deciduous woodland habitats that host diverse wildlife. The forest is protected as a national park, limiting development and agricultural use to protect the landscape and wildlife. Large areas of the New Forest are open common lands kept as a grassland plagioclimax by grazing animals, which include many domesticated farm animals, such as cattle, pigs and horses, which are not segregated in fields. Several species of deer and other wild animals also graze the forest.

Much of the coastal landscape of the Hampshire Basin results from sea level rise in the Flandrian (after the last ice age) some 6000 years BP. There are several large estuaries and rias, notably the 12 mile long Southampton Water and the large convoluted Portsmouth Harbour. The Solent, which separates the Isle of Wight from the coast of Hampshire, is itself a flooded river valley, further erosion having broken the remaining chalk link with the mainland.

Chalk Downs

In the centre and north of the county the substrate is the Southern England Chalk Formation of Salisbury Plain and the South Downs. These are high hills with steep slopes where they border the clays to the south. The downland supports a calcareous grassland habitat, important for wild flowers and insects, as well as arable agriculture. The hills dip steeply forming a scarp onto the Kennet valley to the north, and dip gently to the south. The highest point in the county is Pilot Hill, which reaches the height of 286m/938ft. The rivers Test and Itchen flow from the downland through green valleys, both supporting trout and other wildlife.

Further north, beyond the downs, the landscape is again lowland clay and gravel heathland, though the north is generally greener and more diverse than the south.

ee also

* Geology of the United Kingdom

References

* Draper, Jo. 1990. "Hampshire". Wimborne: Dovecote Press.