The Craven Fault System is the name applied by geologists to the group of crustal faults in the

Pennines The Pennines (), also known as the Pennine Chain or Pennine Hills, are a range of uplands running between three regions of Northern England: North West England on the west, North East England and Yorkshire and the Humber on the east. Commo ...

that form the southern 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 ...

and which partly bounds the

Craven Basin The Craven Basin is a sedimentary basin in northern England, having the shape of a southerly-tilted graben which was active during the Carboniferous period. It is one of a series of such basins which developed across northern England in this per ...

. Sections of the system's component faults which include the North, Middle and South Craven faults and the Feizor FaultBritish Geological Survey 1:50,000 scale geological map (England and Wales) sheet 60 ''Settle'' are evident at the surface in the form of degraded faults scarps where

Carboniferous Limestone Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and ...

abuts millstone grit. The fault system is approximately coincident with the southwestern edge 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 ...

National Park and the northeastern edge of the

Bowland Fells Bowland at its most general most often refers to: * Forest of Bowland, an area of barren gritstone fells, deep valleys and peat moorland, mostly in north-east Lancashire, England, with a small part in Yorkshire * Trough of Bowland, a valley and high ...

Location

The Craven Faults are major crustal fractures across the

. These faults constitute a zone crossing the backbone of England from west to east commencing near

Leck, Lancashire Leck is a civil parish in the English county of Lancashire. The parish of Leck had a population of 189 recorded in the 2001 census. In the 2011 census Leck was grouped with Ireby (2001 pop. 78) to give a total of 260. It is located next to the ...

at then branching three ways: * The North Craven Fault extends about to . * The Mid Craven Fault extends about to . * The South Craven Fault extends about to .
British Geological Survey, Geology of England and IOM, DiGMapGB625, data NERC 2008 The Craven Gap is sometimes called the

Aire Gap Aire Gap is a pass through the Pennines in England formed by geologic faults and carved out by glaciers. The term is used to describe a geological division, a travel route, or a location that is an entry into the Aire river valley. Geology Ge ...

, but to do so necessitates including the Aire Fault; that runs from the south end of the South Craven Fault: from Gargrave towards Leeds. Although of less amplitude than the three Craven faults the course of the Aire Fault is made more apparent by the

River Aire The River Aire is a major river in Yorkshire, England, in length. The ''Handbook for Leeds and Airedale'' (1890) notes that the distance from Malham to Howden is direct, but the river's meanderings extend that to . Between Malham Tarn and Ai ...

. The broad Aire Gap separates the

from the

and the Millstone Grit plateaux of the

South Pennines The South Pennines is a region of moorland and hill country in northern England lying towards the southern end of the Pennines. In the west it includes the Rossendale Valley and the West Pennine Moors. It is bounded by the Greater Manchester co ...

Geological age

The fault system comprises the North Craven Fault, Middle Craven Fault, South Craven Fault and Feizor Fault along with various other unnamed faults. The Middle Craven Fault moved mainly during

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

times and marks the southern limit of the Askrigg Block. However the North and South Craven faults continued to be active into post-

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

times. The Great Scar Limestone is exposed north of the Middle Craven Fault at

Malham Cove Malham Cove is a large curved limestone formation north of the village of Malham, North Yorkshire, England. It was formed by a waterfall carrying meltwater from glaciers at the end of the last Ice Age more than 12,000 years ago. Today it is a w ...

and at

Gordale Scar Gordale Scar is a limestone ravine northeast of Malham, North Yorkshire, England. It contains two waterfalls and has overhanging limestone cliffs over high. The gorge could have been formed by water from melting glaciers or a cavern collapse. T ...

and along the South Craven Fault at

Giggleswick Giggleswick, a village and civil parish in the Craven district of North Yorkshire, England, lies on the B6480 road, less than north-west of the town of Settle and divided from it by the River Ribble. It is the site of Giggleswick School. T ...

Scar.

Erosion

The Great Scar Limestone is over 200 metres thick and the overlying

Yoredale Series The Yoredale Series, in geology, is a now obsolete term for a local phase of the Carboniferous rocks of the north of England, ranging in age from the Asbian Substage to the Yeadonian Substage. The term Yoredale Group is nowadays applied to the ...

was over 300 metres thick before

weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...

. The vertical throw of the fault zone is up to . Near

Ingleton, North Yorkshire Ingleton is a village and civil parish in the Craven district of North Yorkshire, England. The village is from Kendal and from Lancaster on the western side of the Pennines. It is from Settle. The River Doe and the River Twiss meet to f ...

the North Craven Fault has a downthrow of about , and a few hundred yards away the South Craven Fault has a downthrow of about . The fault plane of the North Craven Fault is exposed in Swilla Glen.

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended fr ...

used the Craven Fault to illustrate how nature can so well conceal dramatic events: "The Craven Fault, for instance, extends for upwards of 30 miles, and along this line the vertical displacement of strata has varied from 600 to 3000 feet."

Gallery

File:Giggleswick Scar - geograph.org.uk - 42107.jpg,

Scar File: Hillside above Settle and the Langcliffe mills - geograph.org.uk - 782271.jpg, View NW across Ribble to Giggleswick Scar File:Warrendale Knotts - geograph.org.uk - 114740.jpg, Warrendale Knotts File:Cross Field Knotts - geograph.org.uk - 1034650.jpg, Cross Field Knotts

References

Bibliography

* *

External links

*{{cite web , url=http://www.yorkshire-dales.com/craven-fault.html , title=The Craven Fault , publisher=www.yorkshire-dales.com , accessdate=2009-09-14 Geology of North Yorkshire Geology of the Pennines Geology of Lancashire