|
Moine Supergroup
The Moinian or just the Moine, formerly the Moine Supergroup, is a sequence of Neoproterozoic metasediments that outcrop in the Northwest Highlands of Scotland between the Moine Thrust Belt to the northwest and the Great Glen Fault to the southeast and one part of the Grampian Highlands to the southeast of the fault. It takes its name from ''A' Mhòine'', a peat bog in northern Sutherland. History of research The metamorphic rocks that are now known informally as "the Moine" were originally interpreted as of Silurian age, as they lie in sequence with Cambrian to lower Silurian sedimentary rocks (now known to be lower Ordovician at the youngest and part of the Ardvreck Group). This view, espoused particularly by Roderick Murchison, a geologist known as the "Master of the Silurian", was opposed by James Nicol, who thought that the contact (or "zone of complication" as he called it) was tectonic in nature and that the metamorphic rocks were older and not in stratigraphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roderick Murchison
Sir Roderick Impey Murchison, 1st Baronet (19 February 1792 – 22 October 1871) was a Scottish geologist who served as director-general of the British Geological Survey from 1855 until his death in 1871. He is noted for investigating and describing the Silurian, Devonian and Permian systems. Early life and work Murchison was born at Tarradale House, Muir of Ord, Ross-shire, the son of Barbara and Kenneth Murchison. His wealthy father died in 1796, when Roderick was four years old, and he was sent to Durham School three years later and then to the Royal Military College, Great Marlow, to be trained for the army. In 1808, under Wellesley, he landed in Portugal, and was present at the actions of Roliça and Vimeiro in the Peninsular War as an ensign in the 36th Regt of Foot. Subsequently, under Sir John Moore, he took part in the retreat to Corunna and the final battle there. After eight years of service Murchison left the army and married Charlotte Hugonin (1788–1869 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaannus
A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) are more exact. The modern calendar year, as reckoned according to the Gregorian calendar, approximates the tropical year by using a system of leap years. The term 'year' is also used to indicate other periods of roughly similar duration, such as the lunar year (a roughly 354-day cycle of twelve of the Moon's phasessee lunar calendar), as well as periods loosely associated with the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recogn ... [...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 believe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained ( phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detrital Zircon Geochronology
Detrital zircon geochronology is the science of geochronology, analyzing the age of zircons deposited within a specific sedimentary rock, sedimentary unit by examining their inherent radioisotopes, most commonly the uranium–lead dating, uranium–lead ratio. Zircon is a common Accessory mineral, accessory or trace mineral constituent of most granite and felsic igneous rocks. Due to its hardness, durability and chemical inertness, zircon persists in sedimentary deposits and is a common constituent of most sands. Zircons contain trace amounts of uranium and thorium and can be dated using several modern analytical techniques. Detrital zircon geochronology has become increasingly popular in geological studies from the 2000s mainly due to the advancement in radiometric dating techniques. Detrital zircon age data can be used to constrain the maximum depositional age, determine provenance (geology), provenance, and reconstruct the tectonic setting on a regional scale. Detrital zirco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross Of Mull
The Ross of Mull (Scottish Gaelic: ''An Ros Mhuileach'') is the largest peninsula of the Isle of Mull, about long, and makes up the south-western part of the island. It is bounded to the north by Loch Scridain and to the south by the Firth of Lorne. The main villages are Bunessan and Fionnphort, with smaller settlements including Ardtun, Camas, Carsaig, Knockan, Pennyghael and Uisken. Knocknafenaig, Suidhe, and Shiaba are three of the many cleared settlements on the Ross. Historically the area's main industries consisted of crofting, fishing, kelp, and granite quarries. By 2011 this had shifted with tourism becoming the greatest employer accounting for 29% of employment, while between them farming and fishing made up 15%. The 1886 novel ''Kidnapped'' by Robert Louis Stevenson is partially set on the island of Erraid, a tidal island to the south west of the Ross of Mull. The 1945 film '' I Know Where I'm Going!'', directed by Michael Powell and Emeric Pressburger, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formation) and the changes that may occur in those attributes over a geographic area. A facies encompasses all the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock. The term "facies" was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy, which replaced the earlier notions of '' Neptunism''. Walther's law Walther's law of facies, or simply Walther's law, named after the geologist Johannes Walther, states that the vertical succession of facies reflects lateral changes in environment. Conversely, it states that when a depositional environment "migrates" laterally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithology
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone. Lithology is the basis of subdividing rock sequences into individual lithostratigraphic units for the purposes of mapping and correlation between areas. In certain applications, such as site investigations, lithology is described using a standard terminology such as in the European geotechnical standard Eurocode 7. Rock type The naming of a lithology is based on the rock type. The three major rock types are igneous, sedimentary, and metamorphic. Igneous rocks are formed directly from magma, which is a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caledonian Orogeny
The Caledonian orogeny was a mountain-building cycle recorded in the northern parts of the British Isles, the Scandinavian Caledonides, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly 490–390 million years ago ( Ma). It was caused by the closure of the Iapetus Ocean when the Laurentia and Baltica continents and the Avalonia microcontinent collided. The orogeny is named for Caledonia, the Latin name for Scotland. The term was first used in 1885 by Austrian geologist Eduard Suess for an episode of mountain building in northern Europe that predated the Devonian period. Geologists like Émile Haug and Hans Stille saw the Caledonian event as one of several episodic phases of mountain building that had occurred during Earth's history.McKerrow ''et al.'' (2002) Current understanding has it that the Caledonian orogeny encompasses a number of tectonic phases th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sgurr Beag Thrust
The Sgurr Beag Thrust is an important tectonic structure within the Neoproterozoic metasedimentary rock sequences of the Scottish Highlands. The thrust, or similar structures correlated with it, form the boundary between rocks of the Glennfinnan Group and the underlying Morar Group. It divides the Wester Ross Supergroup from the Loch Ness Supergroup. The history of this structure remains poorly understood although it is thought to be at least partly of Caledonian age. Extent The Sgurr Beag Thrust was identified as a zone of high strain in the western part of the Highlands and was originally called the "Sgurr Beag Slide". It is currently interpreted to extend from the Morvern peninsula in the southwest (with a possible extension onto the Isle of Mull), to the Dornoch Firth where it disappears beneath the Old Red Sandstone. It is often marked by the presence of inliers of Lewisian basement, which are found in its hanging-wall (structurally above the fault plane). In eastern Suthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Red Sandstone
Old Red Sandstone, abbreviated ORS, 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 eastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the paleocontinent 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. The presence of ''Old'' in the name is to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain. Sedimentology The Old Red Sandstone describes a group of sedimentary rocks deposited in a variety of environments in the late Silurian, through the Devonian and into the earliest part of the Carboniferous. The body of rock, or facies, is dominated by terrigenous deposits and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
