The Dent Fault is a major

fault zone 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 ...

on the boundary between the counties of

Cumbria Cumbria ( ) is a ceremonial and non-metropolitan county in North West England, bordering Scotland. The county and Cumbria County Council, its local government, came into existence in 1974 after the passage of the Local Government Act 1972. Cumb ...

and

North Yorkshire North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of ...

in northern

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. It is named after the village of

Dent Dent may refer to: People * Dent (surname) * Dent May (active 2007), American musician * Dent Mowrey (1888–1960), American composer, musician and music teacher * Dent Oliver (1918–1973), international speedway rider Places France * Dent d' ...

Dentdale Dentdale is a dale or valley in the north-west of the Yorkshire Dales National Park in Cumbria, England. It is the valley of the River Dee, but takes its name from the village of Dent. The dale runs east to west, starting at Dent Head, which ...

, on the western margin of the

Yorkshire Dales The Yorkshire Dales is an upland area of the Pennines in the Historic counties of England, historic county of Yorkshire, England, most of it in the Yorkshire Dales National Park created in 1954. The Dales comprise river valleys and the hills ri ...

. The fault, or rather the 'Dent Fault System' – a collection of closely associated faults and folds, defines the western edge of the

Askrigg Block The Askrigg Block is the name applied by geologists to the crustal block forming a part of the Pennines of northern England and which is essentially coincident with the Yorkshire Dales. It is defined by the Dent Fault to the west and the Craven ...

, 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 that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

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 superimpose ...

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 crustal faults in the Pennines that form the southern edge of the Askrigg Block and which partly bounds the Craven Basin. Sections of the system's component faults which ...

near

Kirkby Lonsdale Kirkby Lonsdale () is a town and civil parish in the South Lakeland district of Cumbria, England, on the River Lune. Historically in Westmorland, it lies south-east of Kendal on the A65. The parish recorded a population of 1,771 in the 2001 ...

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

Regional setting

The Carboniferous geology of northern England consists of a series of relatively high and stable "blocks", such as the

Alston Block The Alston Block is a term used by geologists to describe the geological structure of the North Pennines of northern England and which forms a part of the Pennine Block & Basin Province which originated during the Carboniferous period. It is defin ...

separated by actively subsiding "basins", generally referred to as "troughs", such as the

Stainmore Stainmore is a remote geographic area in the Pennines on the border of Cumbria, County Durham and North Yorkshire. The name is used for a civil parish in the Eden District of Cumbria, England, including the villages of North Stainmore and South ...

and Gainsborough Troughs. Some of the blocks are underpinned by granitic intrusions of either Ordovician or Devonian 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 A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of ...

related to north-directed

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

beneath

Avalonia Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent underlie south-west Great Britain, southern Ireland, and the eastern coast of North America. It is the source of many of the older rocks of Wester ...

. Later in the Carboniferous, the onset of

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

to the south of Avalonia, caused widespread reactivation of the extensional faults in reverse. Many of the basin show signs of

inversion Inversion or inversions may refer to: Arts * , a French gay magazine (1924/1925) * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas * Inversion (music), a term with various meanings in music theory and musical set theory * ...

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