Aston Rowant Cutting

Aston Rowant Cutting is a 3.5-hectare (8.6-acre) geological Site of Special Scientific Interest south of Aston Rowant in Oxfordshire.[1][2] It is a Geological Conservation Review site.[3]

Aston Rowant Cutting

Site of Special Scientific Interest
Area of Search	Oxfordshire
Grid reference	SU 732 964[1]
Interest	Geological
Area	3.5 hectares (8.6 acres)[1]
Notification	1986[1]
Location map	Magic Map

Aston Rowant Cutting, also known as the Stokenchurch Gap or Aston Hill cutting, or locally "The Canyon" [4] is a steep chalk cutting, constructed through the Chiltern Hills on the border between Buckinghamshire and Oxfordshire, England during the early 1970s for the M40 motorway. It is 1,200 metres long and a maximum of 47 metres deep, and is located approximately eight miles (13 km) from High Wycombe and close to the village of Stokenchurch. Despite the names, the cutting is in the parish of Lewknor rather than Aston Rowant or Stokenchurch.

The cutting provides the best exposure in central England dating to the Coniacian stage of the Late Cretaceous, approximately 88 million years ago. It is part of the Upper Chalk succession, and at its base there is a fossil rich section which is important in defining the boundary between the Coniacian and the preceding Turonian stage.[5]

The curved route of the cutting was designed to mitigate impact on the skyline, and to fit the local topography. The construction of this section of the M40 (junctions 5–8) was at the time extremely controversial, since the cutting through the Chiltern Hills was driven through the middle of the ecologically-important Aston Rowant NNR. Conservation groups were appalled at the unexpected decision of the inspector at the public inquiry to reject their claims that the national nature reserve designation implied a fully protected landscape which should in no circumstances be damaged. Their alternative proposals for a tunnelled solution, or a route on-line with the existing A40, were rejected.

To a great degree, the inspector's decision, and the subsequent endorsement of that decision by the Secretary of State, proved a "wake-up" call to conservation groups across the country, so that when a similar case arose in the 1980s regarding the Winchester-Bypass section of the M3 at Twyford Down a far more robust — though ultimately unsuccessful — response was forthcoming.

Red kites are commonly seen flying within the cutting or on the surrounding downland, making their return after their persecution by game keepers in Victorian times following a successful reintroduction programme organised by the RSPB and Natural England,[6] which selected the Aston Rowant NNR as one of four initial sites in the UK for a captive release programme using birds brought in from Spain.[7] The scheme has been so successful that the population has grown to over 200 pairs and is now self-generating and supplies birds for similar release programmes elsewhere in the UK.[4][8]

The cutting features prominently in the opening titles to the BBC comedy series The Vicar Of Dibley. [9]