Investigation of North West Solent Peat Deposits
Over the last 200 years there has been a significant loss of mudflats from the coast in the western Solent, this has been exposing a buried prehistoric land surface and peat deposits. These peat deposits can be compared to the upper peats off the north coast of the Isle of Wight.
The area between Hurst Castle and Pitts Deep is currently being investigated.
Various methods are being used to identify and record the peat beds, drift dives record changes in seabed over large areas, in other places spot dives are carried out where an underwater cliff had been identified.
Augering deposits in the NW Solent (PBARG)
Peat deposits found were sampled using an auger core. All the information gained goes towards building a better picture of the landscape that existed when the Solent was a river and was utilised for habitation before becoming the drowned valley which we see today.
This project gained a massive boost in 2001 when SEA Ltd (Submetrix) carried out a swath bathemetric survey of the North West Solent coast from Tanners Hard to West of the Lymington River.
3D colour enhanced image of the underwater landscape east of the Lymington River (SEA Ltd)
The high resolution data produced has given us detailed information on the submerged deposits, this has allowed us to plot the underwater cliff which marks the extent of the deposits.
Diving is now targeting very specific areas of interest, including the cliff at the deposits edge and interesting channels which may be the remains of palaeochannels.
During 2001 and 2002 survey, monitoring and sampling have been carried out at several sites. At Tanners Hard erosion is uncovering more peat and submerged land surface each year, here samples were taken from a section of underwater cliff. The samples were radio carbon dated and analysed and are revealing an interesting sequence of environmental changes connected to the formation of the Solent River and the severing of the Isle of Wight. Monitoring pins are now in place to measure rates of erosion.
The area west of Hurst Spit has also been subject to survey, initial drift dives identified further peat deposits. The seabed in this area is subjected to different tidal and biological regimes, this has resulted in the peat being heavily scoured and pitted.