List of geological faults of Wales
Encyclopedia
This is a list of the named geological faults affecting the rocks of Wales
. See the main article on faults for a fuller treatment of fault types and nomenclature but in brief, the main types are normal faults, reverse faults, thrusts or thrust faults and strike-slip faults. Many faults may have acted as both normal faults at one time and as reverse or thrust faults at another and may or may not have also incorporated some degree of strike-slip movement too. Fault zones, fault belts and fault complexes typically describe assemblages of faults which have a common origin and history and whose alignments tend to be sub-parallel to one another.
There are also a number of 'disturbances'
, notably in South Wales
. These linear features are a combination of faults and folds
- the relative importance of faulting and folding varying along the length of each disturbance.
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...
. See the main article on faults for a fuller treatment of fault types and nomenclature but in brief, the main types are normal faults, reverse faults, thrusts or thrust faults and strike-slip faults. Many faults may have acted as both normal faults at one time and as reverse or thrust faults at another and may or may not have also incorporated some degree of strike-slip movement too. Fault zones, fault belts and fault complexes typically describe assemblages of faults which have a common origin and history and whose alignments tend to be sub-parallel to one another.
There are also a number of 'disturbances'
Disturbance (geology)
A disturbance is a linear zone of disturbed rock strata stretching for many miles across country which comprises a combination of folding and faulting...
, notably in South Wales
South Wales
South Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...
. These linear features are a combination of faults and folds
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...
- the relative importance of faulting and folding varying along the length of each disturbance.
Key to tables
- Column 1 indicates the name of the fault. Note that different authors may use different names for the same fault or a section of it. Coversely the same name may be applied to more than one fault, particularly in the case of smaller faults which are widely separated. Names are as they appear in the literature and do not necessarily conform to the commonly accepted modern spelling or form of the place-names with which they are associated.
- Column 2 indicates the OS grid reference of the approximate midpoint of certain faults. Note that the mapped extent of a fault may not accurately reflect its actual extent.
- Column 3 indicates the countyCountyA county is a jurisdiction of local government in certain modern nations. Historically in mainland Europe, the original French term, comté, and its equivalents in other languages denoted a jurisdiction under the sovereignty of a count A county is a jurisdiction of local government in certain...
in which the fault occurs. Some traverse two or more counties of course.
- Column 4 indicates on which sheet, if any, of the British Geological SurveyBritish Geological SurveyThe 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...
's 1:50,000 / 1" scale geological map series of England and Wales, the fault is shown and named (either on map/s or cross-section/s or both). Also listed are a handful of BGS maps at other scales, where the fault is both shown and named.
- Column 5 indicates a selection of publications in which references to the fault may be found. See references section for full details of publication.
A
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Aber Dinlle Fault Aber Dinlle Fault The Aber Dinlle Fault is a SW-NE trending fault in North Wales. It forms part of the Menai Strait Fault System, with the Berw and Dinorwic Faults. It lies close to the epicentre of the 1984 Llŷn Peninsula earthquake, although it is not thought to have been responsible for that event. The fault was... |
Gwynedd | Brenchley & Rawson 2006 | ||
| Aber Fault | Glamorganshire | E&W 248 | ||
| Aber Richard Fault | E&W 194; 210 | |||
| Aberdaron Fault | Gwynedd | E&W 133 | ||
| Abergwesyn Fault | E&W 196, 212 | |||
| Abertridwr Fault | Glamorganshire | E&W 249 | ||
| Acorn Fault | E&W 230 | |||
| Afon Saint Fault | Gwynedd | E&W 133 | ||
| Allt y Crib Fault | E&W 163 | |||
| Allt y Grug Fault | E&W 230 | |||
| Alyn Valley Fault | E&W 108 | |||
| Anafon Fault | Gwynedd | E&W 106 | ||
| Arthog - Caerdeon Fault | E&W 149 | |||
| Axton Fault | Flintshire | E&W 96 | ||
| Bala - Llanelidan Fault | Smith et al. 2005 | |||
B
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Bala Fault Bala Fault Bala Fault is a SW-NE trending geological fault in Wales that extends offshore into Cardigan Bay. In the offshore area it is a major normal fault and forms the bounding structure to the Cardigan Bay Basin, with a fill including about 2500 m of Lias Group. At its northeastern end it links to the... |
E&W 135; 136 | |||
| Bala Fault Zone | UK (south) 625K | |||
| Beddgelert Fault Beddgelert Fault Beddgelert Fault is a SW-NE trending volcanotectonic fault in North Wales that formed part of a graben system within the collapsed Snowdon caldera structure. It was a focus for later felsic intrusions and hydrothermal activity.... |
Gwynedd | E&W 119 | ||
| Beech Hill Fault | Monmouthshire | Usk-Cwm:25K | ||
| Benton Fault Benton Fault Benton Fault is a geological fault in southern Pembrokeshire in Wales that was active as a normal fault during the deposition of the Devonian Old Red Sandstone, forming a thick half graben. During the Carboniferous, the Benton Fault was strongly inverted as part of the Variscan Orogeny.... |
Pembrokeshire | E&W 228 | Brenchley & Rawson 2006 | |
| Berach Fault | E&W 230 | |||
| Berw Fault Berw Fault The Berw Fault is a SW-NE trending fault in North Wales. It forms part of the Menai Straits fault System, with the Dinorwic Fault and the Aber Dinlle Fault. It has a long history of movement with early ductile fabrics preserved from a sinistral strike-slip sense shear zone active at the end of the... |
Anglesey | Brenchley & Rawson 2006 | ||
| Berw Fault Complex | Anglesey | Brenchley & Rawson 2006 | ||
| Bethel Fault | Glamorganshire | E&W 247 | ||
| Bettws Fault | E&W 230 | |||
| Blaenavon Fault | Monmouthshire | E&W 232 | ||
| Blaenhirwaun Thrust | E&W 230 | |||
| Bodafon Thrust | Anglesey | Brenchley & Rawson 2006 | ||
| Bodelwyddan Fault | Denbighshire | E&W 95; 107 | ||
| Box Fault | Glamorganshire | E&W 247 | ||
| Bristol Channel Fault Zone Bristol Channel Fault Zone Bristol Channel Fault Zone is a geological fault in Wales, it is an inverted basin... |
Bristol Channel | |||
| Bronnant Fault | E&W 210; 211 | |||
| Bronnant Fault Zone | E&W 195 | |||
| Brothers Fault | Glamorganshire | E&W 247 | ||
| Brwynd Overthrust | E&W 163 | |||
| Bryn Eglwys Fault | E&W 120 | Brenchley & Rawson 2006 | ||
| Bryn Morgan Thrust | E&W 230 | |||
| Bryn Posteg Fault | E&W 164 | |||
| Brynderi Fault | Monmouthshire | Mem E&W 233/250 | ||
| Bryneglwys Fault | E&W 121 | |||
| Bryngwili Fault | E&W 230 | |||
| Bryngwyn Fault | Glamorganshire | E&W 230; 247 | ||
| Bryn-y-maen Fault | Denbighshire | E&W 95 | ||
| Bwlchgwyn Fault | E&W 108 | |||
| Bylchau Fault | Denbighshire | E&W 107 | ||
C
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Cae Parc Fault | Glamorganshire | E&W 247 | ||
| Caerdeon Bodlyn Fault | Merionethshire | E&W 135 | ||
| Caergwrle Fault | E&W 108 | |||
| Caerleon Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Caerphilly Fault | Glamorganshire | E&W 249 | ||
| Camdwr Fault | E&W 163 | |||
| Capel Garmon Fault | E&W 107 | |||
| Cardigan - Fishguard Fault Belt | Pembrokeshire | E&W 210 | ||
| Carmel Fault (Powys) | Powys | E&W 179 | ||
| Carmel Fault (Carmarthenshire) | Carmarthenshire | E&W 230 | ||
| Carmel Head Thrust Carmel Head Thrust Carmel Head Thrust is a geological fault on the northern part of the island of Anglesey in North Wales, where rocks of the Precambrian Mona Complex are thrust over Lower Paleozoic sedimentary rocks.... |
UK (south) 625K | Brenchley & Rawson 2006 | ||
| Carrog Valley Fault | Ceredigion | E&W 178 | ||
| Cascade Overthrust | E&W 163 | |||
| Castell Fault | E&W 163 | |||
| Cefn Bryn Thrust | Glamorganshire | E&W 246 | ||
| Cefn Crib Fault | Glamorganshire | E&W 249 | ||
| Cefn Fault | E&W 107 | |||
| Cefn Garw Fault | Monmouthshire | Mem E&W 233/250 | ||
| Cefn Ila Fault | Monmouthshire | Usk-Cwm:25K | ||
| Cefnamwlch-Rhiw Fault | Gwynedd | E&W 134 | ||
| Ceibwr Bay Fault Ceibwr Bay Fault The Ceibwr Bay Fault is a WSW-ENE trending fault zone that cuts Ordovician rocks of the Ashgill Nantmel Mudstones Formation and the Caradoc Dinas Island Formation. The fault is exposed on the south side of Cardigan Bay in Wales and forms part of the Fishguard-Cardigan Fault Zone. It extends from... |
E&W 193 | |||
| Ceidio Fault | Anglesey | Brenchley & Rawson 2006 | ||
| Ceunant Fault | E&W 149 | |||
| Chapel Fault | E&W 231 | |||
| Chepstow Fault | Monmouthshire | Mem E&W 233/250 | ||
| Church Stretton Fault System | Brenchley & Rawson 2006 | |||
| Church Stretton Fault Zone | E&W 213 | |||
| Cilfeigan Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Claerwen Fault Claerwen Fault The Claerwen Fault is a major SW-NE trending fault in central Wales. It was active as a normal fault during deposition of Late Ordovician to mid-Silurian sedimentary rocks, downthrowing to the northwest. The estimated throw on the fault increases from about 100 m at a shallow level to about 1000 m... |
E&W 179 | |||
| Clwyd Fault | Smith et al. 2005 | |||
| Clydach Bridge Fault | Monmouthshire | E&W 232 | ||
| Clywedog Fault | E&W 164 | |||
| Coalbrook Fault | E&W 230 | |||
| Coed Hir Fault | E&W 231 | |||
| Coed Ithel Fault | Monmouthshire | Mem E&W 233/250 | ||
| Coed-y-paen Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Conwy Valley Fault | Gwynedd | E&W 106 | ||
| Copper Works Fault | Glamorganshire | E&W 247 | ||
| Cors-bol Fault | Anglesey | Brenchley & Rawson 2006 | ||
| Craig Twrch Fault | E&W 212 | |||
| Craignant - Milton Fault | Smith et al. 2005 | |||
| Craignant Fault | Smith et al. 2005 | |||
| Craig-y-beri Fault | E&W 137 | |||
| E&W 137 | ||||
| Creigydd Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Cribarth Fault 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... |
E&W 213 | |||
| Crick Fault | Monmouthshire | Mem E&W 233/250 | ||
| Cross Ash Fault | Monmouthshire | Mem E&W 233/250 | ||
| Crychan Fault | Powys | E&W 196, 213 | ||
| Crychan Fault Belt | E&W 213 | |||
| Cwm Cayo Brook Fault | Monmouthshire | Mem E&W 233/250 | ||
| Cwm Cynnen Fault | E&W 211 | |||
| Cwm Dockin Fault | E&W 165 | |||
| Cwm Dwfnant Fault | E&W 196 | |||
| Cwm Earl Fault | E&W 165 | |||
| Cwm Felin Fault | Glamorganshire | E&W 247 | ||
| Cwm Llwyd Fault Cwm Llwyd Fault The Cwm Llwyd Fault is a fault in the Black Mountains of South Wales. It moved as a sinistral strike-slip fault during the Variscan Orogeny. Together with the Llwyn Celyn Fault it formed a left-stepping offset that created a pull apart structure, which preserved the Cwm Llwyd Outlier of Namurian... |
E&W 230 | |||
| Cwm Pennant Fault Cwm Pennant Fault The Cwm Pennant Fault is a SSW-NNE trending normal fault system in North Wales. It forms part of the structures that bound the Snowdon graben. The main faults of the Cwm Pennant fault system throw down to the east.... |
Brenchley & Rawson 2006 | |||
| Cwm Pit Fault | Glamorganshire | E&W 247 | ||
| Cwm Sylwi Fault | E&W 149; 163 | |||
| Cwmcarvan Fault | Monmouthshire | Mem E&W 233/250 | ||
| Cwm-dows Fault | Glamorganshire | E&W 249 | ||
| Cwmgwineu Fault | Glamorganshire | E&W 247 | ||
| Cwmllynfell Fault | E&W 230 | |||
| Cwm-Mawr Fault | E&W 196 | |||
| Cwmmawr Thrust | E&W 230 | |||
| Cwmneol Faul | E&W 231 | |||
| Cymmer Fault | Glamorganshire | E&W 248 | ||
| Cynheidre Thrust | E&W 230 | |||
| Cynllaith Fault | E&W 137 | |||
D
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Daren Ddu Fault | Glamorganshire | E&W 249 | ||
| Daron Fault | Gwynedd | E&W 133 | ||
| Denbigh Fault | E&W 107 | |||
| Dinas Fault 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... (Powys) |
Powys | E&W 231 | ||
| Dinas Fault (Glams) | Glamorganshire | E&W 248 | ||
| Dinorwic Fault | Gwynedd | E&W 106 | ||
| Dip Fach Fault | E&W 231 | |||
| Dolforwyn Fault | E&W 165 | |||
| Dowlais Fault (Mons) | Monmouthshire | E&W 231; 232 | ||
| Dowlais Fault (Glams) | Glamorganshire | E&W 249 | ||
| Duffryn Fault | Glamorganshire | E&W 230, 247 | ||
| Dulas Fault | E&W 196 | |||
| Dulas Gap Fault | Denbighshire | E&W 95; 107 | ||
| Dyfngwm Fault | E&W 164 | |||
| Dylife Esgairgaled Fault | E&W 164 | |||
| Dylife Fault | E&W 164 | |||
| Dynant Fault | E&W 230 | |||
| Dysynni Fault | E&W 149 | |||
E
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| East Llangerniew Fault | E&W 107 | |||
| Efailnewydd Fault | Gwynedd | E&W 134 | ||
| Energlyn Fault | Glamorganshire | E&W 249 | ||
| Erroxhill Fault | Pembrokeshire | E&W 228 | ||
F
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Felin Arw Fault | Glamorganshire | E&W 248 | ||
| Ferry Fault | Glamorganshire | E&W 247 | ||
| Flint Fault | E&W 108 | |||
| Forge Overthrust | E&W 149; 163 | |||
G
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Gadlys Fault | Glamorganshire |
E&W 231; 248 | ||
| Gardeners Fault | Glamorganshire | E&W 230; 247 | ||
| Garth - Llanwrtyd Fault Belt | E&W 212 | |||
| Garth Fault | E&W 196, 213 | |||
| Garth Ferry Fault | Anglesey | Brenchley & Rawson 2006 | ||
| Garth Hill Overthrust | Glamorganshire | E&W 249 | ||
| Gelli Fault | Glamorganshire | E&W 249 | ||
| Gelligaer Fault | Glamorganshire | E&W 249 | ||
| Gelli-goch Overthrust | E&W 149; 163 | |||
| Giant's Grave Fault | Glamorganshire | E&W 247 | ||
| Glan Hafren Fault | E&W 165 | |||
| Glanalders Fault | E&W 179 | |||
| Glandyfi Fault | E&W 163 | |||
| Glaslyn Valley Fault | Brenchley & Rawson 2006 | |||
| Glyn Ceiriog Fault | E&W 121 | |||
| Glyn Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Glyn Valley Fault | E&W 135 | |||
| Glyn Wallis Fault | E&W 230 | |||
| Glyncorrwg Fault | Glamorganshire | E&W 231; 248 | ||
| Gnoll Fault | Glamorganshire | E&W 247 | ||
| Gop Fault | Flintshire | E&W 95 | ||
| Gors Fault | Glamorganshire | E&W 230, 247 | ||
| Gorseinon Fault | Glamorganshire | E&W 247 | ||
| Great Ewloe Fault | E&W 108 | |||
| Greenland Fault | Monmouthshire | E&W 232 | ||
| Gresford Fault | E&W 121 | |||
| Grib Fault | E&W 230 | |||
| Groes Fault | E&W 107 | |||
| Grovesend Fault | Glamorganshire | E&W 230; 247 | ||
| Guilsfield Fault | Powys | E&W 151 | ||
| Gwaynynog Fault | E&W 107 | |||
| Gwern-ddu Fault | Monmouthshire | Mem E&W 233/250 | ||
| Gwespyr Fault | Flintshire | E&W 96 | ||
| Gwili Fault | Glamorganshire | E&W 230, 247 | ||
| Gwrych Castle Fault | Denbighshire | E&W 95; 107 | ||
| Gyrnos Fault | E&W 231 | |||
H
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Hafan Fault | E&W 163 | |||
| Hawarden Fault | E&W 108 | |||
| Hendre Fault | E&W 230 | |||
| Highgate Fault | E&W 164; 165 | |||
| Hirwaun No 1 Fault | E&W 231 | |||
| Hirwaun No 2 Fault | E&W 231 | |||
| Hirwaun No 2a Fault | E&W 231 | |||
| Hirwaun No 3 Fault | E&W 231 | |||
| Hudnalls Fault | Monmouthshire | Mem E&W 233/250 | ||
| Itton Fault | Monmouthshire | Mem E&W 233/250 | ||
I,J,K
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| John Grey's Fault | Glamorganshire | E&W 247 | ||
| Keepers Lodge Fault | E&W 230 | |||
| Kilkenny Fault | Glamorganshire | E&W 231; 249 | ||
| King's Wood Fault | Monmouthshire | Mem E&W 233/250 | ||
| Kinmel Park Fault | Denbighshire | E&W 95 | ||
L
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Leeswood Fault | E&W 108 | |||
| Llanbadoc Fault | Monmouthshire | E&W 232; Usk-Cwm:25K | ||
| Llancayo Fault | Monmouthshire | E&W 233 | Mem E&W 233/250 | |
| Llandrindod - Pen-y-waun Fault Belt | E&W 213 | |||
| Llandyfan Fault | E&W 230 | |||
| Llandynan Fault | E&W 121 | |||
| Llanegryn Fault | E&W 149 | |||
| Llanelidan Fault | E&W 121 | |||
| Llanerchyraur Fault | E&W 164 | |||
| Llanfabon Fault | Glamorganshire | E&W 231; 249 | ||
| Llanfrechfa Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Llangattock Fault | Mem E&W 233/250 | |||
| Llanglydwen Fault | E&W 210; 211 | |||
| Llangollen - Llantysilio - Aqueduct Fault | Smith et al. 2005 | |||
| Llangollen Fault | E&W 121 | |||
| Llangwm Fault | Monmouthshire | Mem E&W 233/250 | ||
| Llanhilleth Fault | Glamorganshire | E&W 249 | ||
| Llannefydd Fault | E&W 107 | |||
| Llanrhaeadr Fault | E&W 107 | |||
| Llantysilio Fault | E&W 121 | |||
| Llanvair Discoed Fault | Monmouthshire | Mem E&W 233/250 | ||
| Llanvair Fault | Monmouthshire | E&W 250 | ||
| Llanvihangel Fault | Monmouthshire | Mem E&W 233/250 | ||
| Llanwonno Fault | Glamorganshire | E&W 248 | ||
| Llanwrtyd Fault | E&W 196 | |||
| Llanwrtyd Fault | E&W 213 | |||
| Llechwedd Fault | E&W 164 | |||
| Llethir Fault | E&W 230 | |||
| Llety Wilws Fault | E&W 230 | |||
| Llwyn Celyn Fault | E&W 230 | |||
| Llwyn Fault | E&W 165 | |||
| Llyfnant Fault | E&W 163 | |||
| Llysfaen Fault | Denbighshire | E&W 95 | ||
| Longoaks Fault | Glamorganshire | E&W 247 | ||
| Lunnon Fault | Glamorganshire | E&W 247 | ||
M
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Maes-gwyn Fault | E&W 107 | |||
| Marian Ffrith Fault | Flintshire | E&W 95 | ||
| Mathern Fault | Monmouthshire | Mem E&W 233/250 | ||
| Mawddach Fault | E&W 149 | |||
| Menai Strait Fault System Menai Strait The Menai Strait is a narrow stretch of shallow tidal water about long, which separates the island of Anglesey from the mainland of Wales.The strait is bridged in two places - the main A5 road is carried over the strait by Thomas Telford's elegant iron suspension bridge, the first of its kind,... |
Brenchley & Rawson 2006 | |||
| Merthyr Church Fault | Glamorganshire | E&W 231; 249 | ||
| Meusydd Fault | E&W 230 | |||
| Minera Fault Belt | E&W 121 | |||
| Minffordd Fault | Brenchley & Rawson 2006 | |||
| Mochras Fault | Merionethshire | E&W 135; 49 | Brenchley & Rawson 2006 | |
| Moelfre Fault | Merionethshire | E&W 135 | ||
| Moel-Gilau Fault | Glamorganshire | E&W 248 | ||
| Morfa Fault | Glamorganshire | E&W 247, 248 | ||
| Morlais Fault | Glamorganshire | E&W 247 | ||
| Mount Pleasant Fault | E&W 230 | |||
| Mynydd Bach Fault | E&W 195 | |||
N
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Nant Marl Fault | E&W 230 | |||
| Nant y Fedw Fault | E&W 196 | |||
| Nant-Figillt Fault | E&W 108 | |||
| Nantmor Fault | Gwynedd | E&W 119 | ||
| Nantygwrdy Fault | E&W 164 | |||
| Nantyricket Fault | E&W 164 | |||
| Nedern Fault | Monmouthshire | Mem E&W 233/250 | ||
| Nercwys - Nant-Figillt Fault Zone | E&W 108 | |||
| New House Thrust | E&W 165 | |||
| Newcastle Fault | Monmouthshire | Mem E&W 233/250 | ||
| Newlands Thrust | Glamorganshire | E&W 247, 248 | ||
| Newton Fault | Glamorganshire | E&W 247 | ||
| Newmarket Fault | Flintshire | E&W 95 | ||
| Newport Sands Fault | E&W 193; 210 | |||
| Nicholaston Fault | Glamorganshire | E&W 247 | ||
O
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Ogof Cadno Fault | E&W 193 | |||
| Ogof Fault | E&W 163 | |||
| Olway Brook Fault | Monmouthshire | Mem E&W 233/250 | ||
P,Q
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Palleg Fault | E&W 230 | |||
| Palmer's Lake Overthrusts | Pembrokeshire | E&W 244/5 | ||
| Pant Fault | Denbighshire | E&W 95 | ||
| Paper Mill Fault | E&W 108 | |||
| Pared Fault | Gwynedd | E&W 133 | ||
| Parwyd Fault | Gwynedd | E&W 133 | ||
| Pendaren Fault | Glamorganshire | E&W 249 | ||
| Penffordd Fault | Pembrokeshire | E&W 210 | ||
| Pengam Fault | Glamorganshire | E&W 249 | ||
| Pennal Fault | E&W 149; 163 | |||
| Penrhiwfelen Fault | Glamorganshire | E&W 247 | ||
| Penterry Fault | Monmouthshire | Mem E&W 233/250 | ||
| Pentre Clwydau Fault | E&W 231 | |||
| Pentre Llanharan Thrust | Glamorganshire | E&W 248 | ||
| Pentremawr Lag Fault | Carmarthenshire | E&W 229 | ||
| Pentwyn Fault (Mons) | Monmouthshire | E&W 249 | ||
| Pentwyn Fault (Glams) | Glamorganshire | E&W 249 | ||
| Pen-y-castell Fault | Glamorganshire | E&W 231, 248 | ||
| Penydarren Fault | E&W 231 | |||
| Pen-y-Fan Fault | Monmouthshire | E&W 232 | ||
| Pen-y-llan Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Pen-y-parc Fault | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
| Plas Isaf Fault | Glamorganshire | E&W 247 | ||
| Pont Morlais Fault | E&W 230 | |||
| Pontarsais Fault | E&W 212 | |||
| Pontypool Road Fault | Monmouthshire | E&W 232 | ||
| Port Eynon Thrust | Glamorganshire | E&W 246 | ||
| Portskewett Hill Fault | Mem E&W 233/250 | |||
| Prestatyn Fault | E&W 95 | |||
| Pwllau Bach Fault | E&W 231 | |||
| Pwllmawr Fault | Glamorganshire | E&W 247 | ||
| Pwll-meyric Fault | Monmouthshire | Mem E&W 233/250 | ||
R
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Ramsey Fault | Pembrokeshire | E&W 209 | ||
| Reservoir Fault | Monmouthshire | Mem E&W 233/250 | ||
| Rhadyr Fault | Monmouthshire | Usk-Cwm:25K | ||
| Rhaiadr Fault | E&W 137 | |||
| Rhiw Fault | Glamorganshire | E&W 249 | ||
| Rhiw Gwraidd Fault | E&W 179 | |||
| Rhobell Fracture | Brenchley & Rawson 2006 | |||
| Rhos Fault | Glamorganshire | E&W 231; 232; 249 | ||
| Rhuallt Fault | Flintshire | E&W 95 | ||
| Rhydding Fault | Glamorganshire | E&W 230; 247 | ||
| Ritec Fault | Pembrokeshire | Brenchley & Rawson 2006 | ||
| Road Uchaf Fault? | Brenchley & Rawson 2006 | |||
| Rock Park Fault | E&W 196 | |||
| Rockfield Fault | Monmouthshire | Mem E&W 233/250 | ||
S
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Sarn-Abersoch Thrust | Gwynedd | E&W 134 | ||
| Sawdde Fault | E&W 212 | |||
| Severn Valley Fault Belt | E&W 151 | Toghill P. 2006 | ||
| Siamber Wen Fault | Denbighshire | E&W 95; 107 | ||
| Sirhowy Fault | Monmouthshire | E&W 232 | ||
| Six Pit Fault | Glamorganshire | E&W 247 | ||
| Soflen Fault | E&W 107 | |||
| Soughton Fault | E&W 108 | |||
| St Arvans Fault | Monmouthshire | Mem E&W 233/250 | ||
| St Brides Fault | Monmouthshire | Mem E&W 233/250 | ||
| Stradey Fault | Carmarthenshire | E&W 229 | ||
| Strumble Head Fault | Pembrokeshire | E&W 210 | ||
| Swansea Fault | Glamorganshire | E&W 247 | ||
| Swansea Valley Fault | E&W 213 | |||
| Syddyn Fault | Carmarthenshire | E&W 229 | ||
T
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Talgarth Fault | Monmouthshire | Mem E&W 233/250 | ||
| Tal-y-coed Fault | Monmouthshire | Mem E&W 233/250 | ||
| Tal-y-llyn Fault | E&W 149 | |||
| Tanant Fault | E&W 137 | |||
| Teifi Fault | E&W 212 | |||
| Tintern Fault | Monmouthshire | Mem E&W 233/250 | ||
| Tirdonkin Fault | Glamorganshire | E&W 247 | ||
| Tonfannau Fault | E&W 149 | |||
| Trafle Fault | Glamorganshire | E&W 247 | ||
| Trawsfynydd - Cwm Bowyd Fault | Brenchley & Rawson 2006 | |||
| Trawsfynydd Fault | MW&M:250K, E&W 135 | |||
| Tredegar Fault | Monmouthshire | E&W 231; 232 | ||
| Tre-fal-du Fault | Monmouthshire | Mem E&W 233/250 | ||
| Trelleck Common Fault | Monmouthshire | Mem E&W 233/250 | ||
| Trelleck Fault | Monmouthshire | Mem E&W 233/250 | ||
| Tremadog Thrust Zone | Brenchley & Rawson 2006 | |||
| Tre-'r-ddol Fault | E&W 163 | |||
| Trevethin Fault | Glamorganshire, Monmouthshire | E&W 232; 249 | ||
| Trinant Fault | Glamorganshire | E&W 249 | ||
| Tumble Fault | E&W 230 | |||
| Tweedle Fault | E&W 231 | |||
| Twrch Fechan Fault | E&W 230 | |||
| Twyn Sych Fault | E&W 231 | |||
| Ty Llwyd Fault | E&W 230 | |||
| Tyn-y-caeau Fault (Denb) | Denbighshire | E&W 95 | ||
| Ty'n-y-caeau Fault (Mons) | Monmouthshire | E&W 249; Usk-Cwm:25K | ||
U,V
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Upper Artro Fault | Merionethshire | E&W 135 | ||
| Usk Fault | Monmouthshire | Mem E&W 233/250 | ||
| Vale of Clwyd Fault | Denbighshire | E&W 121; 95 | ||
| Van Fault | E&W 164 | |||
W,X,Y,Z
| Fault name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Warren Fault | E&W 230 | |||
| Welsh Borderland Fault Welsh Borderland Fault System The Welsh Borderland Fault System is a zone of faulting and associated folding which runs northeastwards through Wales from Pembrokeshire through Carmarthenshire and Powys into Shropshire in England... |
Smith et al. 2005 | |||
| Welsh Borderland Fault System Welsh Borderland Fault System The Welsh Borderland Fault System is a zone of faulting and associated folding which runs northeastwards through Wales from Pembrokeshire through Carmarthenshire and Powys into Shropshire in England... |
UK (south) 625K | Brenchley & Rawson 2006 | ||
| Wenallt Fault | E&W 164 | |||
| Werf Fault | E&W 231 | |||
| West Llangerniew Fault | E&W 107 | |||
| Weston Madoc Fault | E&W 165 | |||
| Wonastow Fault | Monmouthshire | Mem E&W 233/250 | ||
| Wrexham Fault | E&W 121 | |||
| Yspytty Ifan Fault | E&W 120 | |||
| Ystwyth Fault | E&W 179 | |||
List of Disturbances
The following named features comprise both faulting and folding;| Disturbance name | OS map ref | County | BGS map sheet | book reference/s |
|---|---|---|---|---|
| Caerbryn Disturbance | Carmarthenshire | 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... |
Carmarthenshire | E&W 230 | ||
| Clun Forest Disturbance | ||||
| 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... |
Powys | E&W 230, 231 | ||
| Llandyfaelog Disturbance | Carmarthenshire | E&W 231 | ||
| Llannon (or Llanon) Disturbance | Carmarthenshire | 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... |
E&W 231 | |||
| Pontyclerc Disturbance | Carmarthenshire | E&W 230 | ||
| Saron Disturbance | Carmarthenshire | E&W 230 | ||
| Trimsaran Disturbance | ||||
Maps
- 1:625,000 scale geological map 2007, Bedrock Geology UK South, British Geological Survey, Keyworth, Notts (UK (south) 625K)
- 1:250,000 scale geological map Mid Wales and the Marches, British Geological Survey, Keyworth, Notts (MW & M 250K)
- various of 1:50,000 scale geological maps of England and Wales, British Geological Survey, Keyworth, Notts (E & W no.)
- 1:25,000 scale sheet Usk - Cwmbran in Classic Areas of British Geology series, British Geological Survey, Keyworth, Notts (Usk-Cwm: 25K)
Books
- Brenchley, PJ & Rawson, PF (eds) 2006. The Geology of England and Wales, (2nd edn) The Geological Society, London (Brenchley & Rawson 2006)
- Smith et al. 2005 Structure & Evolution of the south-west Pennine Basin and adjacent area. Subsurface memoir of the British Geological Survey. (Smith et al. 2005)
- Toghill, P 2006 Geology of Shropshire (2nd edn) Crowood Press, Wilts (Toghill P 2006)
- Welch, FBA & Trotter, FM 1961 Geology of the Country around Monmouth and Chepstow, HMSO (explanation of 1" geol. sheets 233 & 250 (England and Wales) (Welch, FBA & Trotter, FM 1961)
See also
- List of geological faults of England
- List of geological faults of Northern Ireland
- List of geological faults of Scotland
- List of geological folds in Great Britain
- Geological structure of Great BritainGeological structure of Great BritainThe geological structure of Great Britain is complex, resulting as it does from a long and varied geological history spanning more than two billion years...