Hampshire's geology falls into two categories. In the south, along the coast, are relatively weak Eocene and Oligocene clays and gravels which are protected from sea erosion by the Isle of Purbeck, Dorset, and the Isle of Wight. These low, flat lands support heathland and woodland habitats, a large area of which, the New Forest, is lagely unspoilt and was designated a National Park in 2004.

In the 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 South Downs are also a candidate for National Park status.

See also

• Geology of the United Kingdom