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Harlech Dome
The Harlech Dome is a geological dome in southern Snowdonia in north Wales. It extends approximately from Blaenau Ffestiniog in the north to Tywyn in the south, and includes Harlech, The Rhinogydd, Barmouth and Cadair Idris. The geological layer structure comprises Cambrian sedimentary, volcanic and intrusive rocks from the lower Paleozoic age approximately 4.5 km thick. The geology contains the Harlech Grits Group, Mawddach Group, Rhobell Volcanic Group and Aran Volcanic Group. The area contains a wide range of metallic minerals and has been mined for (copper, silver, zinc, manganese, gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...) in the past. References Rock formations of Gwynedd {{UK-geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dome (geology)
A dome is a feature in structural geology consisting of symmetrical anticlines that intersect each other at their respective apices. Intact, domes are distinct, rounded, spherical-to- ellipsoidal-shaped protrusions on the Earth's surface. However, a transect parallel to Earth's surface of a dome features concentric rings of strata. Consequently, if the top of a dome has been eroded flat, the resulting structure in plan view appears as a bullseye, with the youngest rock layers at the outside, and each ring growing progressively older moving inwards. These strata would have been horizontal at the time of deposition, then later deformed by the uplift associated with dome formation. Formation mechanisms There are many possible mechanisms responsible for the formation of domes, the foremost of which are post-impact uplift, refolding, and diapirism. Post-impact uplift A complex crater, caused by collision of a hypervelocity body with another larger than itself, is typified by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Intrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent; as a rubber additive; and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese was first isolated in 1774. It is familiar in the laboratory in the form of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aran Volcanic Group
The Aran Volcanic Group is a geologic group in Wales. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in Wales This is a list of fossiliferous stratigraphic units in Wales. See also *Lists of fossiliferous stratigraphic units in Europe *Lists of fossiliferous stratigraphic units in the United Kingdom References * {{DEFAULTSORT:Fossiliferous stra ... References * * https://data.bgs.ac.uk/id/Lexicon/NamedRockUnit/AVG.html Geologic formations of Wales Ordovician System of Europe Ordovician Wales {{Wales-stub Fossiliferous stratigraphic units in Wales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhobell Fawr
Rhobell Fawr is the site of an ancient volcano that was active during the Early Ordovician period in the Arenig range within the Snowdonia National Park. Despite its modest height of 734 m (2,408 feet), it is a mountain with views of higher peaks all around, including the north face of Cadair Idris and distant Snowdon. The paths are not well trodden, but there is a distinct path up from Bwlch Goriwared, a couple of miles north-north-east of the small village of Llanfachreth Llanfachreth is a settlement approximately three miles north-east of Dolgellau, Gwynedd, in the community of Brithdir and Llanfachreth within the historic boundaries of Merionethshire ( cy, Meirionnydd, Sir Feirionnydd), Wales. History Llan .... References {{reflist External links www.geograph.co.uk : photos of Rhobell Fawr and surrounding area Mountains and hills of Snowdonia Marilyns of Wales Nuttalls Hewitts of Wales Volcanoes of Wales Ordovician volcanoes Brithdir and Llan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mawddach Group
The Mawddach Group is a middle to upper Cambrian lithostratigraphy, lithostratigraphic group (stratigraphy), group (a sequence of rock strata) in Gwynedd, Wales. The name is derived from the river known as the Afon Mawddach. Outcrops The rocks are exposed across the Rhinogydd, Harlech Dome and southern Snowdonia. Lithology and stratigraphy The Group comprises around 2400m thickness of mudstones, sandstones and siltstones laid down in the marine Welsh Basin during the middle to late Cambrian period. The Group comprises (in descending order i.e. oldest last) the Dol-cyn-Afon Formation, the Dolgellau Formation, the Ffestiniog Flags Formation, the Maentwrog Formation and the Clogau Formation.http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=MWG (BGS on-line lexicon of rock units) References {{Reflist Cambrian System of Europe Geology of Wales Fossiliferous stratigraphic units in Wales Geologic formations of the United Kingdom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harlech Grits Group
The Harlech Grits Group is a lower to middle Cambrian lithostratigraphic group (a sequence of rock strata) in northwest Wales. The name is derived from the town of Harlech in Gwynedd. Outcrops The rocks are exposed beneath Harlech and across the Harlech Dome to its east; a broad anticlinal structure which encompasses the Rhinogydd range. Lithology and stratigraphy The group comprises about 2000m thickness of sandstone, mudstones, siltstones and greywackes laid down in the marine Welsh Basin The Welsh Basin was a northeast-southwest aligned back-arc depositional basin during the Cambrian, Ordovician and Silurian periods during which a considerable thickness of marine sediments was laid down in the area. To the southeast lay the Midlan ... during the early to mid Cambrian period. The group comprises (in descending order i.e., oldest last) the Gamlan Formation, the Barmouth Formation, the Hafotty Formation, the Rhinog Formation, the Llanbedr Formation and the Dolwen Formation.htt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Rock
Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks. For these reasons, in geology, volcanics and shallow hypabyssal rocks are not always treated as distinct. In the context of Precambrian shield geology, the term "volcanic" is often applied to what are strictly metavolcanic rocks. Volcanic rocks and sediment that form from magma erupted into the air are called "volcaniclastics," and these are technically sedimentary rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate boundaries and in flood basalt provinces. It has been estimated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
