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Benton Fault
The Benton Fault is a geological fault in southern Pembrokeshire in Wales that was active as a normal fault during the deposition of the Old Red Sandstone during the Devonian period, forming a thick half graben. During the 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 ..., the Benton Fault was strongly inverted as part of the Variscan Orogeny. See also * List of geological faults of Wales References Geology of Wales {{Wales-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
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 forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A '' fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pembrokeshire
Pembrokeshire ( ; cy, Sir Benfro ) is a county in the south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and the rest by sea. The county is home to Pembrokeshire Coast National Park. The Park occupies more than a third of the area of the county and includes the Preseli Hills in the north as well as the Pembrokeshire Coast Path. Historically, mining and fishing were important activities, while industry nowadays is focused on agriculture (86 per cent of land use), oil and gas, and tourism; Pembrokeshire's beaches have won many awards. The county has a diverse geography with a wide range of geological features, habitats and wildlife. Its prehistory and modern history have been extensively studied, from tribal occupation, through Roman times, to Welsh, Irish, Norman, English, Scandinavian and Flemish influences. Pembrokeshire County Council's headquarters are in the county town of Haverfordwest. The council has a majority of Independ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in 2021 of 3,107,500 and has a total area of . Wales has over of coastline and is largely mountainous with its higher peaks in the north and central areas, including Snowdon (), its highest summit. The country lies within the Temperateness, north temperate zone and has a changeable, maritime climate. The capital and largest city is Cardiff. Welsh national identity emerged among the Celtic Britons after the Roman withdrawal from Britain in the 5th century, and Wales was formed as a Kingdom of Wales, kingdom under Gruffydd ap Llywelyn in 1055. Wales is regarded as one of the Celtic nations. The Conquest of Wales by Edward I, conquest of Wales by Edward I of England was completed by 1283, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Red Sandstone
The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the ancient continent of Euramerica/Laurussia. In Britain it is a lithostratigraphic unit (a sequence of rock strata) to which stratigraphers accord supergroup status and which is of considerable importance to early paleontology. For convenience the short version of the term, ORS is often used in literature on the subject. The term was coined to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain. Sedimentology The Old Red Sandstone describes a suite of sedimentary rocks deposited in a variety of environments during the Devonian but extending back into the late Silurian and on into the earliest part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began domina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half Graben
A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults. Rift and fault structure A rift is a region where the lithosphere extends as two parts of the Earth's crust pull apart. Often a rift will form in an area of the crust that is already weakened by earlier geological activity. Extensional faults form parallel to the axis of the rift. An extensional fault may be seen as a crack in the crust that extends down at an angle to the vertical. As the two sides pull apart, the hanging wall ("hanging over" the sloping fault) will move downward relative to the footwall. The crust thins and sinks, forming a rift basin. Warm mantle material wells up, melting the crust and often causing volcanoes to emerge in the rift basin. Extensional basins may appear to be caused by a graben, or depressed block of land, sinking between parallel normal faults that dip towards th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' (" coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inversion (geology)
In structural geology inversion or basin inversion relates to the relative uplift of a sedimentary basin or similar structure as a result of crustal shortening. This normally excludes uplift developed in the footwalls of later extensional faults, or uplift caused by mantle plumes. "Inversion" can also refer to individual faults, where an extensional fault is reactivated in the opposite direction to its original movement. The term ''negative inversion'' is also occasionally used to describe the reactivation of reverse faults and thrusts during extension. The term "inversion" simply refers to the fact that a relatively low-lying area is uplifted – the rock sequence itself is not normally inverted. Formation Many inversion structures are caused by the direct reactivation of pre-existing extensional faults. In some cases only the deeper parts of the fault are reactivated and the shortening is accommodated over a much broader area in the shallow part of the section. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variscan Orogeny
The Variscan or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Variscan'', comes from the Medieval Latin name for the district '' Variscia'', the home of a Germanic tribe, the Varisci; Eduard Suess, professor of geology at the University of Vienna, coined the term in 1880. ( Variscite, a rare green mineral first discovered in the Vogtland district of Saxony in Germany, which is in the Variscan belt, has the same etymology.) ''Hercynian'', on the other hand, derives from the Hercynian Forest. Both words were descriptive terms of strike directions observed by geologists in the field, ''variscan'' for southwest to northeast, ''hercynian'' for northwest to southeast. The ''variscan'' direction reflected the direction of ancient fold belts cropping out throughout Germany and adjacent countries and the meaning shifted f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Geological Faults Of Wales
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. Key to tables *Column 1 indicates the name of the fault. Note that different authors may use different names for the sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
