Poole Bay is a bay

Headlands and bays

Headlands and bays are two related features of the coastal environment.- Geology and geography :Headlands and bays are often found on the same coastline. A bay is surrounded by land on three sides, whereas a headland is surrounded by water on three sides. Headlands are characterized by high,...

 in the English Channel

English Channel

The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...

, off the coast of Dorset

Dorset

Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...

 in southern England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

, which runs from the mouth of Poole Harbour

Poole Harbour

Poole Harbour is a large natural harbour in Dorset, southern England, with the town of Poole on its shores. The harbour is a drowned valley formed at the end of the last ice age and is the estuary of several rivers, the largest being the Frome. The harbour has a long history of human settlement...

 in the west to Hengistbury Head

Hengistbury Head

Hengistbury Head is a headland jutting into the English Channel between Bournemouth and Milford on Sea in the English county of Dorset.At the end is a spit which creates the narrow entrance to Christchurch Harbour.-Location:...

 in the east. It consists of steep sandstone cliffs and several 'chines' that allow easy access to the sandy beaches below. Poole Bay is a relatively shallow embayment delimited by the Poole Harbour

Poole Harbour

Poole Harbour is a large natural harbour in Dorset, southern England, with the town of Poole on its shores. The harbour is a drowned valley formed at the end of the last ice age and is the estuary of several rivers, the largest being the Frome. The harbour has a long history of human settlement...

 tidal inlet to the southwest and Hengistbury Head/Christchurch Ledge. The coast along the bay is continuously built up, and is part of the South East Dorset conurbation

South East Dorset conurbation

The South east Dorset conurbation is a multi-centred conurbation on the south coast of Dorset in England. The area is rapidly becoming an amalgamation with the area of South West Hampshire immediately on the fringe of the newly formed New Forest National Park...

, including parts of the towns of Poole

Poole

Poole is a large coastal town and seaport in the county of Dorset, on the south coast of England. The town is east of Dorchester, and Bournemouth adjoins Poole to the east. The Borough of Poole was made a unitary authority in 1997, gaining administrative independence from Dorset County Council...

, Bournemouth

Bournemouth

Bournemouth is a large coastal resort town in the ceremonial county of Dorset, England. According to the 2001 Census the town has a population of 163,444, making it the largest settlement in Dorset. It is also the largest settlement between Southampton and Plymouth...

 and Christchurch

Christchurch

Christchurch is the largest city in the South Island of New Zealand, and the country's second-largest urban area after Auckland. It lies one third of the way down the South Island's east coast, just north of Banks Peninsula which itself, since 2006, lies within the formal limits of...

. The bay is sometimes erroneously referred to as Bournemouth Bay, due to part of it lying within the borough of Bournemouth.

Many of the beaches along Poole Bay were replenished during the winters of 2005 and 2006 with 1.1 million m³ of sand dredged from Poole Harbour and 700,000 m³ of sand dredged from a Licensed Area off the Isle of Wight. A dedicated website has more information and charted progress with photos and a daily diary http://www.poolebay.net/. The project was completed on January 23, 2007.

Geology

The area of Poole Bay was predominantly created during the Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 period, when the Solent river ran across the whole of South East Dorset and West Hampshire, out past the Isle of Wight

Isle of Wight

The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...

 The solid geology of the cliffs, and the seabed beneath Poole Bay, is composed of rocks of the Tertiary Bracklesham Group, consisting of a sequence of fine, medium and coarse sands. At Hengistbury Head there are younger rocks of the Bartonian group, forming an outlier . The Barton Clay here is made up of a series of sands and interbedded clays, with four distinct bands of ironstone nodules. These formations dip eastwards and are cut out by a north-west to south-east trending fault. This defines the eastwards boundary of Christchurch Ledge, which is a seawards continuation of the resistant ironstone strata exposed in Hengistbury Head.