List of Sites of Special Scientific Interest in County Durham


This is a list of the Sites of Special Scientific Interest in County Durham, England. It excludes SSSIs situated in that area south of the River Tyne that is now part of the metropolitan county of Tyne and Wear as well as the area north of the River Tees which, prior to 1996, formed part of the county of Cleveland.
As of July 2010, County Durham has 88 sites that have been designated as SSSIs, of which 67 have been designated for their biological interest, 16 for their geological interest, and 5 for both.
Five of these sites are shared with an adjacent county:
Sites of Special Scientific Interest are areas that have been selected for special protection because of their floral, faunal or geological significance. The concept was first given a statutory basis in the National Parks and Access to the Countryside Act 1949, the relevant provisions of which were repeated in the Wildlife and Countryside Act 1981. Under the 1949 Act, responsibility for selecting and notifying SSSIs in England was delegated to the newly created Nature Conservancy, which was replaced in 1973 by the Nature Conservancy Council. In 1991, the NCC was split up, its responsibilities in England being passed to English Nature which, in turn, was amalgamated into a new body, Natural England, in 2006.
The process for establishing an SSSI is as follows:
The initial notification of a site is accompanied by a citation sheet, which outlines the reasons for the notification: the data in the following list is summarised from these individual citation sheets.

Reasons for notification as SSSI

Of the 88 SSSIs designated in County Durham, 67 have been designated for their biological interest, 16 for their geological interest, and five for both biological and geological interest.

Biological

While many of the SSSIs designated for biological reasons cover a variety of habitats, most have been designated primarily for one of a small number of reasons, as detailed in the individual citation sheets:
The surface geology of County Durham is largely confined to rocks dating from the Carboniferous and Permian periods. In the west of the county, outcrops of Dinantian limestones are found in the river valleys, while the upland areas are underlain by the younger Namurian Millstone Grit Series. To the east, these rocks dip beneath the Westphalian Coal Measures, which underlay a broad swathe in the centre of the county. Further east, the Coal Measures are overlain by Permian Magnesian Limestone, which forms a low plateau across the eastern part of the county. Igneous intrusions are a prominent feature of the geology and gave rise to extensive mining for lead and other minerals, especially in the upper Weardale area in the west of the county.
Although each SSSI designated for geological reasons has its own distinctive features, they fall into a small number of broad categories, as indicated in the individual citation sheets:
From its inception, English Nature classified sites using the 1974–1996 county system. As Natural England uses the same system, it is also adopted in the following list. As a result, some sites that lie within the ceremonial county of Durham and might therefore be expected to be listed here will be found instead in either the Cleveland or the Tyne and Wear lists.
For other counties, see List of SSSIs by Area of Search.

Sites