Linford

Also within

Antrim County Antrim Coast and Glens Scenic Area

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Habitats

Fast flowing river and stream

Geology & landscape

Geological Feature: Cave / Cavern, Karst, Rock Outcrop · Mining / Industrial: Quarry · Geological Period: Carboniferous, Cretaceous, Paleogene · Rock Type: Basalt, Limestone

Landscape processes: Coastal, Karst, Periglacial, Volcanic / Igneous

Description

Linford Karst The area is of special scientific interest because of its important physiographical features. Linford is of national importance as it contains surface karst landforms that have developed on the Cretaceous age Ulster White Limestone Formation. In Ireland, karst features are more commonly associated with Carboniferous limestones notably in Counties Fermanagh and Clare. Development of some karst features on the Cretaceous Ulster White Limestone is not uncommon with many sinks recorded around the Antrim plateau and one active cave system also present. However Linford is exceptional in hosting a range of classic surface karst features including dolines, a dry valley, sinks and issues in a relatively small area. The Ulster White Limestone Formation is found at outcrop primarily along the coast of Antrim. In Antrim, the Limestone is usually capped by Palaeogene age basalts of the Antrim Lava Group. This effectively seals much of the limestone against weathering and erosion. Karst landforms are created by the interaction of water and limestone and surface features are more likely to develop where the limestone has a significant areal extent as is the case at Linford. During the last Ice Age, the land surface was scoured by the advance and retreat of ice sheets. Evidence suggests that at Linford the ice removed the basalt covering the limestone. Subsequent development of drainage patterns and limestone dissolution led to the formation of the karst features. Dolines of the type seen at Linford probably formed through the gradual collapse of the land surface due to a combination of dissolution of the limestone and removal of finer grade material leaving a depression on the surface. There are a series of dolines at Linford approximately aligned north-east to south-west. The main surface water flow enters the site from the south but quickly disappears into a number of active or partly active sinkholes. Flow is then underground before re-emerging some 400m to the west to join another water course. A small dry valley probably indicates a former route taken by the surface flow. As the main sink upstream is substantial in size, it is probable that the valley was formed under periglacial conditions when the ground was frozen, the stream was not sinking and flow rates were considerably enhanced by seasonal melt water. The extent of the valley has been increased by limited historical quarrying. A series of apparently abandoned sink holes are also present downstream of the main sink. The site is within the Knockdhu Area of Special Archaeological Interest. The presence of some of the archaeological features here may be associated with the unusual karst landforms present at Linford. https://www.daera-ni.gov.uk/publications/linford-assi

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