FIELD TRIP TO STUDY THE GEOLOGY OF DENBIES VINEYARD, DORKING, SURREY

Surrey, in general, and Dorking in particular, has a long association with wine. Several vineyards flourished in the county during the Little Ice Age of the 17^th and 18^th centuries, notably at Painshill, Albury and Deepdene. In the last century vineyards were planted near Dorking at Thorncroft and Denbies. Denbies covers some 104 hectares (260 acres) and is believed to be the largest vineyard in Europe. It is planted with 19 different cultivars, and produces a range of red, white and sparkling wines. It was established on the recommendation of a notorious local geologist, who, applying the French concept of ‘terroir’, recognised the favourable combination of topography and geology, coupled with the beneficial effects of global warming. The Cretaceous chalk, on which Denbies is largely planted, crops out in the Champagne area of France, and is noted for its dual pore system of fractures and intercoccolithic shelter porosity. The fractures ensure that the vines are always well-drained, but in the dry season they may obtain moisture from the microporosity between the fractures.

South to North cross-section through northern Surrey showing the location of vineyards, ancient and modern. Note their positions on well-drained south-facing slopes.

Resultant upon their appreciation of fine wines the inhabitants of Dorking required cellarage. To this end a series of extensive interconnecting caves were excavated beneath the private and public houses of downtown Dorking. These were cut into the Folkestone Beds of the Lower Greensand, and enable a fossil tidal sand body to be studied from the inside.

 For further details on the winelands of Britain see: www.winelandsofbritain.co.uk

 ITINERARY

10.30 Assemble at Denbies winery car park, one mile north of Dorking on the A24 (TQ163511). The winery is reached from a roundabout with a brown tourist sign. Full details of location are on www.denbiesvineyard.co.uk. Condense into as few cars as possible. Drive into Dorking. 

11.00 Tour of Dorking Caves to see inside a tidal sand body of the Folkestone Sand (Lower Greensand). Opportunity to admire cross-bedding, liesegang ringen, wine vaults and mystery chamber dating back to the late 17^th century (Note: the cave tour is not epic. Hard hats are not required. Sensible shoes - no open-toed sandals). Most of the tour is on one level, but to reach the mystery chamber requires the descent and ascent of a 20metre staircase. This may not suit people with heart problems, pregnancy, claustrophobia or arachnophobia. Asthmatics please bring nebulisers. 

12.00 Tour of Dorking Museum. Opportunity to admire Lord Ashcombe’s spectacular collection of Cretaceous and Pleistocene fossils. 

1.00 Drive to Ranmore Common on the North Downs to stare out over the Wealden anticline to the South Downs, and to see the sites of abandoned Little Ice Age vineyards of the Surrey Hills. Picnic lunch (Please bring your own solids and liquids. There is an opportunity to purchase ice cream at this locality, but nothing more.) 

1.30 Leaving cars in the car park walk from Ranmore Common along the rim of the North Downs turning North to enter the Mole Valley admiring dip and scarp topography, periglacial dry valleys etc.. Descend gently through Denbies vineyard to Denbies winery (Total walking distance about 2.5 miles, all down hill, nothing epic.)

 3.00 Tour of Denbies Winery. This includes a 20 minutes IMAX film on the geology of the vineyard starring a notorious local geologist, a ride in a ‘train’ through the winery and into the cellars for a tutored tasting of three of Denbies wines.

 3.45 Opportunity to buy wine and a diverse range of other items in the winery shop.

 4.15 One or more (as necessary) of the cars parked at Denbies will take the drivers of the cars that were left parked on Ranmore Common to retrieve them. Depart convivially into the bucolic Surrey countryside………