The Dent Fault is a major fault zone on the boundary between the counties of

Cumbria Cumbria ( ) is a ceremonial county in North West England. It borders the Scottish council areas of Dumfries and Galloway and Scottish Borders to the north, Northumberland and County Durham to the east, North Yorkshire to the south-east, Lancash ...

and

North Yorkshire North Yorkshire is a Ceremonial counties of England, ceremonial county in Northern England.The Unitary authorities of England, unitary authority areas of City of York, York and North Yorkshire (district), North Yorkshire are in Yorkshire and t ...

in northern

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. It is named after the village of Dent in Dentdale, on the western margin of the

Yorkshire Dales The Yorkshire Dales are a series of valleys, or Dale (landform), dales, in the Pennines, an Highland, upland range in England. They are mostly located in the Ceremonial counties of England, ceremonial county of North Yorkshire, but extend into C ...

. The fault, or rather the 'Dent Fault System' – a collection of closely associated faults and folds, defines the western edge of the Askrigg Block, a geological structure that underlies the Yorkshire Dales. The fault is associated with the Taythes

Anticline In structural geology, an anticline is a type of Fold (geology), fold that is an arch-like shape and has its oldest Bed (geology), beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex curve, c ...

to its west and the Fell End

Syncline In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed ...

to its east. Other than vertical movement on the fault, there has also been an element of

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

movement. To the north, the fault links with the Pennine Fault System in the vicinity of Brough and with the

Craven Fault System The Craven Fault System is the name applied by geologists to the group of crust (geology), crustal fault (geology), faults in the Pennines that form the southern edge of the Askrigg Block and which partly bounds the Craven Basin. Sections of the ...

near Kirkby Lonsdale to the south.Stone et al. 2010 ''British Regional Geology: Northern England'' (5th edition) Keyworth, Notts, British Geological Survey

Regional setting

The

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

geology of northern England consists of a series of relatively high and stable "blocks", such as the Alston Block separated by actively subsiding "basins", generally referred to as "troughs", such as the Stainmore and Gainsborough Troughs. Some of the blocks are underpinned by granitic intrusions of either

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

age. The block and basin terrain was a result of active extensional faulting, with a dominant N-S extension direction, possibly related to the effects of back-arc spreading related to north-directed

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

beneath

Avalonia Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent are terranes in parts of the eastern coast of North America: Atlantic Canada, and parts of the East Coast of the United States, East Coast of the ...

. Later in the Carboniferous, the onset of

continental collision In geology, continental collision is a phenomenon of plate tectonics that occurs at Convergent boundary, convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroy ...

to the south of Avalonia, caused widespread reactivation of the extensional faults in reverse. Many of the basin show signs of inversion at this time. The dominant shortening direction in northwest England is NNW-SSE.

Geometry

The Dent Fault consists of a series of linked steep SSW-NNE trending sub-parallel faults with associated folds. The northern part of the structure, known as the Dent Line, has the form of a faulted

monocline A monocline (or, rarely, a monoform) is a step-like fold in rock strata consisting of a zone of steeper dip within an otherwise horizontal or gently dipping sequence. Formation Monoclines may be formed in several different ways (see diagram) ...

that eventually links through to the Pennine Fault. The southern part of the fault zone consist of three major fault segments.

References

{{reflist Geology of the Pennines Geology of Cumbria Geology of North Yorkshire