Past change
The ancient Solent River flowed eastwards across the present site of Christchurch Bay and along the main axes of the West and East Solent into a major “English Channel”, south and east of the present day Isle of Wight. All of the modern rivers discharging into the Solent, Christchurch and Poole Bays fed into the Solent River, and therefore drained a large catchment throughout the Pleistocene stage of the Quaternary Period. During the early Holocene period, sea-levels rose rapidly, flooding the East Solent and widening through coastal erosion.Between 8600 and 6800BP the continuous chalk ridge that, extended between The Needles, Isle of Wight and Handfast Point, in the Purbecks was breached by rising sea levels, creating a connection with the shallow but rapidly expanding Christchurch Bay. Erosion of the shoreline and soft cliffs produced sediment that was transported eastwards to form Hurst Spit. Rising sea levels led to the formation of a permanent tidal channel at Hurst Narrows with powerful currents, linking the West Solent to Christchurch Bay.
Increased wave action within the Solent caused erosion of the shore and low soft cliffs, and led to the formation of barrier beaches and spits. Due to the sheltering effect of the Isle of Wight and Hurst Spit, the mainland coast was relatively sheltered against direct wave and tidal action and became characterised by the sedimentation of fine sediments and the growth of tidal flats and fringing saltmarshes.
