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Barra Do Macaé
Barra (; or ; ) is an island in the Outer Hebrides, Scotland, and the second southernmost inhabited island there, after the adjacent island of Vatersay to which it is connected by the Vatersay Causeway. In 2011, the population was 1,174. English and Gaelic are widely spoken, and at the 2011 Census, there were 761 Gaelic speakers (62% of the population, falling from 76% in the 1991 census). Geology In common with the rest of the Western Isles, Barra is formed from the oldest rocks in Britain, the Lewisian gneiss, which dates from the Archaean eon. Some of the gneiss in the east of the island is noted as being pyroxene-bearing. Layered textures or foliation in this metamorphic rock is typically around 30° to the east or northeast. Palaeoproterozoic age metadiorites and metatonalites forming a part of the East Barra Meta-igneous Complex occur around Castlebay as they do on the neighbouring islands of Vatersay and Flodday. A few metabasic dykes intrude the gneiss in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heaval
Heaval is the highest hill on the Outer Hebridean island of Barra, Scotland. The highest point is 383 metres high above sea level and it is located 1.5 km northeast of Castlebay. It is most easily ascended from the south east, from the summit of a 102 m high road pass on the A888 about 1 km east of Castlebay. There is a signposted car park nearby. About halfway up the ridge, there is a white statue of the Virgin and Child. Near the top, the ridge becomes steep, but any difficulties can be bypassed on the south side. The two other hills on Barra with Marilyn (hill), more than 150 metres of topographic prominence, reascent are Ben Tangaval (333 m) in the west, and Ben Cliad (202 m) in the north. Another hill, Theisabhal Mor (190 m) is on Vatersay, which is linked to Barra by the Vatersay Causeway. Five of the Barra Isles, uninhabited islands to the south have summits higher than 150 m. Weather permitting, these islands can be visited, with time for summit ascents, by ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tonalite
Tonalite is an igneous rock, igneous, plutonic (Intrusive rock, intrusive) rock (geology), rock, of felsic composition, with phaneritic (coarse-grained) texture. Feldspar is present as plagioclase (typically oligoclase or andesine) with alkali feldspar making up less than 10% of the total feldspar content. Quartz (SiO2) is present as more than 20% of the total quartz-alkali feldspar-plagioclase-feldspathoid (QAPF classification, QAPF) content of the rock. Amphiboles and biotite are common in lesser quantities, while accessory minerals include apatite, magnetite and zircon. In older references tonalite is sometimes used as a synonym for quartz diorite. However the current IUGS QAPF diagram, classification defines tonalite as having greater than 20% quartz, while quartz diorite varies its quartz content from 5 to 20%. The name is derived from the type locality of tonalites, adjacent to the Tonale Line, a major structural lineament and mountain pass, Tonale Pass, in the Italy, Itali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze Age
The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of the three-age system, following the Stone Age and preceding the Iron Age. Conceived as a global era, the Bronze Age follows the Neolithic, with a transition period between the two known as the Chalcolithic. The final decades of the Bronze Age in the Mediterranean basin are often characterised as a period of widespread societal collapse known as the Late Bronze Age collapse (), although its severity and scope are debated among scholars. An ancient civilisation is deemed to be part of the Bronze Age if it either produced bronze by smelting its own copper and alloying it with tin, arsenic, or other metals, or traded other items for bronze from producing areas elsewhere. Bronze Age cultures were the first to History of writing, develop writin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chambered Cairn
A chambered cairn is a burial monument, usually constructed during the Neolithic, consisting of a sizeable (usually stone) chamber around and over which a cairn of stones was constructed. Some chambered cairns are also passage-graves. They are found throughout Britain and Ireland, with the largest number in Scotland. Typically, the chamber is larger than a cist, and will contain a larger number of interments, which are either excarnated bones or inhumations (cremations). Most were situated near a settlement, and served as that community's "graveyard". Scotland Background During the early Neolithic (4000–3300 BC) architectural forms are highly regionalised with timber and earth monuments predominating in the east and stone-chambered cairns in the west. During the later Neolithic (3300–2500 BC) massive circular enclosures and the use of grooved ware and Unstan ware pottery emerge. Scotland has a particularly large number of chambered cairns; they are found in various diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standing Stone
A menhir (; from Brittonic languages: ''maen'' or ''men'', "stone" and ''hir'' or ''hîr'', "long"), standing stone, orthostat, or lith is a large upright rock (geology), stone, emplaced in the ground by humans, typically dating from the European middle Bronze Age. They can be found individually as monoliths, or as part of a group of similar stones. Menhirs' size can vary considerably, but they often taper toward the top. Menhirs are found across Europe, Africa, and Asia, with a concentration in Western Europe, notably in Ireland, Great Britain, and Brittany. Theories concerning their purpose remain speculative, with hypotheses ranging from Ancient Celtic religion, druidic rituals to territorial markers or elements of an ideological system. Some menhirs feature Engraving, engravings, including anthropomorphic figures and symbols, and are often associated with ancient religious ceremonies and Chamber tomb, burial chambers. Etymology The word ''menhir'' was adopted from F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neolithic Era
The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the History of agriculture, introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of sedentism, settlement. The term 'Neolithic' was coined by John Lubbock, 1st Baron Avebury, Sir John Lubbock in 1865 as a refinement of the three-age system. The Neolithic began about 12,000 years ago, when farming appeared in the Epipalaeolithic Near East and Mesopotamia, and later in other parts of the world. It lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BCE), marked by the development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peat
Peat is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. ''Sphagnum'' moss, also called peat moss, is one of the most common components in peat, although many other plants can contribute. The biological features of sphagnum mosses act to create a habitat aiding peat formation, a phenomenon termed 'habitat manipulation'. Soils consisting primarily of peat are known as histosols. Peat forms in wetland conditions, where flooding or stagnant water obstructs the flow of oxygen from the atmosphere, slowing the rate of decomposition. Peat properties such as organic matter content and saturated hydraulic conductivity can exhibit high spatial heterogeneity. Peatlands, particularly bogs, are the primary source of peat; although less common, other wetlands, including fens, pocosins and peat swamp forests, also deposit peat. Landscapes covered in peat are home to sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borve, Barra
Borve () is a village on the west coast of the island of Barra in the Outer Hebrides, Scotland. Borve is within the parish of Barra, and is situated on the A888 which is the island's circular main road. History There are a number of Neolithic remains nearby, including a burial cairn, and standing stones. A rich Viking burial was unearthed in the vicinity of Borve at a site called Ardvouray in 1862, the contents of which can be found in the British Museum The British Museum is a Museum, public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is the largest in the world. It documents the story of human cu .... The grave included amongst other things a pair of oval brooches, a comb, fragments of a drinking horn, a spear, a pair of shears, a weaving sword and a whetstone. References External links Canmore - Barra, Borve site record [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machair
A machair (; sometimes machar in English) is a fertile low-lying grassy plain found on part of the northwestern coastlines of Ireland and Scotland, particularly the Outer Hebrides. The best examples are found on North and South Uist, Harris and Lewis. Etymology ''Machair'' is a Gaelic word meaning "fertile plain", but the word is now also used in scientific literature to describe the dune grasslands unique to western Scotland and northwest Ireland. It had been used by naturalists since 1926, but the term was not adopted by scientists until the 1940s. The word is used in a number of Irish, Scottish and Manx place names to refer to low-lying fertile ground or fields, even in areas where no machair has ever been supported. In Scotland, some Gaelic speakers use ''machair'' as a general term for the entire dune system, including the dune ridge, while others restrict its use to the extensive flat grasslands inland of the dune ridge. In Ireland, the word has only been used in pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nappe
In geology, a nappe or thrust sheet is a large sheetlike body of rock that has been moved more than or above a thrust fault from its original position. Nappes form in compressional tectonic settings like continental collision zones or on the overriding plate in active subduction zones. Nappes form when a mass of rock is forced (or "thrust") over another rock mass, typically on a low angle fault plane. The resulting structure may include large-scale recumbent folds, shearing along the fault plane,Twiss, Robert J. and Eldridge M. Moores, ''Structural Geology,'' W. H. Freeman, 1992, p. 236 imbricate thrust stacks, fensters and klippes. The term stems from the French word for ''tablecloth'' in allusion to a rumpled tablecloth being pushed across a table. History Nappes or nappe belts are a major feature of the European Alps, Dinarides, Carpathians and Balkans. Since the 19th century many geologists have uncovered areas with large-scale overthrusts. Some of these were su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular '' klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is called a ''blind thrust'' fault. Because of the lack of surface evidence, blind thrust fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Fault
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 geological 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 blur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
