|
Geology Of The Cairngorms National Park
This article describes the geology of the Cairngorms National Park, an area in the Highlands of Scotland designated as a national park in 2003 and extended in 2010. The Cairngorms National Park extends across a much wider area than the Cairngorms massif itself and hence displays rather more varied geology. The majority of the rocks within the National Park belong to the Dalradian Supergroup, a thick sequence of sands, muds and limestones that were deposited between about 800 and 600 million years ago on the margins of the former continent of Laurentia. Rocks now ascribed to the Moine Supergroup occur along the northwestern edge of the Park. The Dalradian and Moine successions were intensely faulted, folded and metamorphosed during the Caledonian Orogeny between about 490 and 430 million years ago Geologists recognize a ‘Grampian event’, centred around 470 million years ago, which was responsible for the initial deformation of the Dalradian and relates to the collision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scottish Highlands
The Highlands ( sco, the Hielands; gd, a’ Ghàidhealtachd , 'the place of the Gaels') is a historical region of Scotland. Culturally, the Highlands and the Lowlands diverged from the Late Middle Ages into the modern period, when Lowland Scots replaced Scottish Gaelic throughout most of the Lowlands. The term is also used for the area north and west of the Highland Boundary Fault, although the exact boundaries are not clearly defined, particularly to the east. The Great Glen divides the Grampian Mountains to the southeast from the Northwest Highlands. The Scottish Gaelic name of ' literally means "the place of the Gaels" and traditionally, from a Gaelic-speaking point of view, includes both the Western Isles and the Highlands. The area is very sparsely populated, with many mountain ranges dominating the region, and includes the highest mountain in the British Isles, Ben Nevis. During the 18th and early 19th centuries the population of the Highlands rose to around 300,000, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is nearly alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grantown-on-Spey
Grantown-on-Spey ( gd, Baile nan Granndach) is a town in the Highland Council Area, Counties of Scotland, historically within the county of Moray. It is located on a low plateau at Freuchie beside the river Spey at the northern edge of the Cairngorms, Cairngorm mountains, about south-east of Inverness ( by road). The town was founded in 1765 as a New town, planned settlement and was originally called simply Grantown after Sir James Grant, 8th Baronet, Sir James Grant. The addition 'on Spey' was added by the burgh council in 1898. The town has several listed 18th and 19th century buildings, including several large hotels and serves as a regional centre for tourism and services in the Strathspey, Scotland, Strathspey region. The town is twinned with Notre-Dame-de-Monts in the Vendée, Pays de la Loire, France. History The burgh was founded in 1765 during the early stages of the Industrial Revolution to encourage both agricultural marketing and handicrafts, as well as to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migmatite
Migmatite is a composite rock found in medium and high-grade metamorphic environments, commonly within Precambrian cratonic blocks. It consists of two or more constituents often layered repetitively: one layer is an older metamorphic rock that was reconstituted subsequently by partial melting ("paleosome"), while the alternate layer has a pegmatitic, aplitic, granitic or generally plutonic appearance ("neosome"). Commonly, migmatites occur below deformed metamorphic rocks that represent the base of eroded mountain chains. Migmatites form under extreme temperature and pressure conditions during prograde metamorphism, when partial melting occurs in metamorphic paleosome. Components exsolved by partial melting are called neosome (meaning ‘new body’), which may or may not be heterogeneous at the microscopic to macroscopic scale. Migmatites often appear as tightly, incoherently folded veins ( ptygmatic folds).Recommendations by the IUGS Subcommission on the Systematics of M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semipelite
A pelite (Greek: ''pelos'', "clay") or metapelite is a metamorphosed fine-grained sedimentary rock, i.e. mudstone or siltstone. The term was earlier used by geologists to describe a clay-rich, fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone, the metamorphosed version of which would technically have been a ''metapelite''. It was equivalent to the now little-used Latin-derived term lutite.Potter, P.E., J.B. Maynard, and P.J. Depetris (2005) ''Muds and Mudstones.'' New York, New York, Springer. 279 pp. Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. A semipelite is defined in part as having similar chemical composition but being of a crystalloblastic nature. Pettijohn (1975) gives the following descriptive terms based on grain size, avoiding the use of terms such as clay or argillaceous which carry an implication of chemical composition. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psammite
Psammite (Greek: ''psammitēs'' "(made) from sand", from ''psammos'' "sand") is a general term for sandstone. It is equivalent to the Latin-derived term areniteU.S. Bureau of Mines Staff (1996) ''Dictionary of Mining, Mineral, & Related Terms.'' Report SP-96-1, U.S. Department of Interior, U.S. Bureau of Mines, Washington, D.C.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute, Washington, DC 779 pp. and is commonly used in various publications to describe a metamorphosed sedimentary rock with a dominantly sandstone protolith A protolith () is the original, unmetamorphosed rock from which a given metamorphic rock is formed. For example, the protolith of a slate is a shale or mudstone. Metamorphic rocks can be derived from any other kind of non-metamorphic rock and ....Tyrell, G. W. (1921) ''Some points in petrographic nomenclature.'' Geological Magazine. v. 58, no. 11, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Badenoch Group
The Badenoch Group is a sequence of metamorphosed Tonian age sedimentary rocks that outcrop across the Central Highlands of Scotland, east of the Great Glen. This rock sequence has formerly been referred to as the Central Highland Migmatite Complex and the Central Highland Division. Badenoch Group rocks extend across the Monadhliath Mountains and some surrounding areas largely between the Great Glen and Ericht-Laidon fault belts though their margins are hidden beneath younger strata; Old Red Sandstone to the north and west and Grampian Group rocks elsewhere. The succession is divided into two subgroups; the Dava Subgroup (previously referred to as the Dava Succession) and the Glen Banchor Subgroup. The former, named from the locality of Dava between Inverness and Grantown-on-Spey includes the Slochd Psammite and Flichity Semipelite formations. The latter is named for Glen Banchor, west of Newtonmore, the type area being from here to Laggan. The Glen Banchor sequence is be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tonian
The Tonian (from grc, τόνος, tónos, meaning "stretch") is the first geologic period of the Neoproterozoic era (geology), Era. It lasted from to Mya (million years ago). Instead of being based on stratigraphy, these dates are defined by the International Commission on Stratigraphy, ICS based on radiometric dating, radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic Era and followed by the Cryogenian. Rifting leading to the breakup of supercontinent Rodinia, which had formed in the mid-Stenian, occurred during this period, starting from 900 to 850 Mya. Biology The first putative metazoan (animal) fossils are dated to the middle to late Tonian ( 890-800 Mya). The fossils of ''Otavia antiqua'', which has been described as a sponge by its discoverers and numerous other scholars, date back to about 800 mya. Even earlier sponge-like fossils have been reported in reefs dating back to 890 million years before the present, but their ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoproterozoic
The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. It is preceded by the Mesoproterozoic Era and succeeded by the Paleozoic Era of the Phanerozoic Eon. The most severe glaciation known in the geologic record occurred during the Cryogenian, when ice sheets may have reached the equator and formed a " Snowball Earth". The earliest fossils of complex multicellular life are found in the Ediacaran Period. These organisms make up the Ediacaran biota, including the oldest definitive animals in the fossil record. According to Rino and co-workers, the sum of the continental crust formed in the Pan-African orogeny and the Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust. Geology At the onset of the Neoproterozoic the supercontine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landslip
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides. Gravity is the primary driving force for a landslide to occur, but there are other factors affecting slope stability that produce specific conditions that make a slope prone to failure. In many cases, the landslide is triggered by a specific event (such as a heavy rainfall, an earthquake, a slope cut to build a road, and many others), although this is not always identifiable. Causes Landslides occur when the slope (or a portion of it) undergoes some processes that change its condition from stable to unstable. This is essentially due to a decrease in the shea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficient carbon sink on the planet, because peatland plants capture carbon dioxide (CO2) naturally released from the peat, maintaining an equilibrium. In natural peatlands, the "annual rate of biomass production is greater than the rate of decomposition", but it takes "thousands of years for peatlands to develop the deposits of , which is the average depth of the boreal orthernpeatlands", which store around 415 gigatonnes (Gt) of carbon (about 46 times 2019 global CO2 emissions). Globally, peat stores up to 550 Gt of carbon, 42% of all soil carbon, which exceeds the carbon stored in all other vegetation types, including the world's forests, although it covers just 3% of the land's surface. ''Sphagnum'' moss, also called peat moss, is one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciation
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago. The Holocene is the current interglacial. A time with no glaciers on Earth is considered a greenhouse climate state. Quaternary Period Within the Quaternary, which started about 2.6 million years before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone. Penultimate Glacial Period The Penultimate Glacial Period (PGP) is the glacial period that occurred before the Last Glacial Period. It began about 194,000 years ago and ended 135,000 years ago, with the beginning of the Eemian interglacial. Last Glacial Period The last glacial period was the most recent glacial period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Peat")
