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. Commonly ...

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. 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 ...

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 county of Yorkshire, England, most of it in the Yorkshire Dales National Park created in 1954. The Dales comprise river valleys and the hills rising from the Vale of York ...

National Park and the northeastern edge of the Bowland Fells. Malham Cove

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 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, 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 A ...

. The broad Aire Gap separates the

from the Bowland Fells and the Millstone Grit plateaux of the South Pennines.

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 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 and at Gordale Scar 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. ...

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 movemen ...

. 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 ...

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 natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

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