A disturbance is a linear zone of disturbed rock strata

Stratum

In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...

 stretching for many miles across country which comprises a combination of folding

Fold (geology)

The term fold is used in geology when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation. Synsedimentary folds are those due to slumping of sedimentary material before it is lithified. Folds in rocks vary in...

 and faulting. The British Geological Survey

British Geological Survey

The British Geological Survey is a partly publicly funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS headquarters are in Keyworth, Nottinghamshire, but other centres...

 record a number of such features in South Wales

Wales

Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

 including the Neath Disturbance

Neath Disturbance

The Neath Disturbance is a geological structure which stretches across south Wales from Swansea Bay northeastwards as far as Hereford in western England. It comprises a series of both faults and associated folds which were active during the mountain-building period known as the Variscan orogeny...

, Pontyclerc Disturbance, Carreg Cennen Disturbance

Carreg Cennen Disturbance

The Carreg Cennen Disturbance is a zone of geological faults and folds in south and mid Wales which forms a part of both the Church Stretton Fault Zone and the Welsh Borderlands Fault System...

 and the Cribarth Disturbance

Cribarth Disturbance

The Cribarth Disturbance is a geological structure forming a lineament which stretches across south Wales from Swansea up the Swansea Valley then northeastwards to Brecon and beyond. It comprises both a series of faults and associated folds which were active during the mountain-building period...

, the latter sometimes also known (at least in part) as the Tawe Valley or Swansea Valley Disturbance. The southwestward continuation of the Carreg Cennen Disturbance is known as the Llandyfaelog Disturbance.

Other examples in Wales and the border counties of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 include the Clun Forest, Saron, Trimsaran and Llannon (or 'Llanon') Disturbances. The Silverdale and Burtreeford Disturbances are found in northern England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

List of Disturbances

The following named features comprise both faulting and folding;

Sortable table of named disturbances

Disturbance name	County	Country	BGS map sheet	book reference/s
Burtreeford Disturbance		England	E&W 31
Caerbryn Disturbance	Carmarthenshire	Wales	E&W 230
Carreg Cennen Disturbance Carreg Cennen Disturbance The Carreg Cennen Disturbance is a zone of geological faults and folds in south and mid Wales which forms a part of both the Church Stretton Fault Zone and the Welsh Borderlands Fault System...		Wales	E&W 230
Clun Forest Disturbance		Wales
Cribarth Disturbance Cribarth Disturbance The Cribarth Disturbance is a geological structure forming a lineament which stretches across south Wales from Swansea up the Swansea Valley then northeastwards to Brecon and beyond. It comprises both a series of faults and associated folds which were active during the mountain-building period...		Wales	E&W 230, 231
Llandyfaelog Disturbance	Carmarthenshire	Wales	E&W 231
Llannon (or Llanon) Disturbance	Carmarthenshire	Wales	E&W 230
Neath Disturbance Neath Disturbance The Neath Disturbance is a geological structure which stretches across south Wales from Swansea Bay northeastwards as far as Hereford in western England. It comprises a series of both faults and associated folds which were active during the mountain-building period known as the Variscan orogeny...		Wales	E&W 231
Pontyclerc Disturbance	Carmarthenshire	Wales	E&W 230
Saron Disturbance	Carmarthenshire	Wales	E&W 230
Silverdale Disturbance		England	E&W 25
Stockdale Disturbance		England		GCR29, p205
Trimsaran Disturbance		Wales

See also List of geological folds in Great Britain.