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Moraines
A moraine is any accumulation of unconsolidated debris ( regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet. It may consist of partly rounded particles ranging in size from boulders (in which case it is often referred to as boulder clay) down to gravel and sand, in a groundmass of finely-divided clayey material sometimes called glacial flour. Lateral moraines are those formed at the side of the ice flow, and terminal moraines are those formed at the foot, marking the maximum advance of the glacier. Other types of moraine include ground moraines (till-covered areas forming sheets on flat or irregular topography) and medial moraines (moraines formed where two glaciers meet). Etymology The word ''moraine'' is borrowed from French , which in turn is derived from the Savoyard Italian ('mound of earth'). in this case was derived from Proven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Moraine
A terminal moraine, also called an end moraine, is a type of moraine that forms at the terminal (edge) of a glacier, marking its maximum advance. At this point, debris that has accumulated by plucking and abrasion, has been pushed by the front edge of the ice, is driven no further and instead is deposited in an unsorted pile of sediment. Because the glacier acts very much like a conveyor belt, the longer it stays in one place, the greater the amount of material that will be deposited. The moraine is left as the marking point of the terminal extent of the ice. Formation As a glacier moves along its path, the surrounding area is continuously eroding. Loose rock and pieces of bedrock are constantly being picked up and transported with the glacier. Fine sediment and particles are also incorporated into the glacial ice. The accumulation of these rocks and sediment together form what is called glacial till when deposited. Push moraines are formed when a glacier retreats from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Till
image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is diagnostic of till. image:Glacial till exposed in roadcut-750px.jpg, Glacial till with tufts of grass Till or glacial till is unsorted glacier, glacial sediment. Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines. Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes. Description Till is a form of '' glacial drift'', which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice. It is distinguished from other forms of drift in that it is dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacier
A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land“Glacier, N., Pronunciation.” Oxford English Dictionary, Oxford UP, June 2024, https://doi.org/10.1093/OED/7553486115. Accessed 25 Jan. 2025. and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water. On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions, but glaciers may be found in mountain ranges on ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murrain
The word "murrain" (like an archaic use of the word "distemper") is an antiquated term covering various infectious diseases affecting cattle and sheep. The word originates from Middle English ''moreine'' or ''moryne'', in parallel to Late Latin ("plague"), a probable derivative of Latin ("to die"). The word "murrain", much like the word "pestilence", did not refer to a specific disease but rather served as an umbrella term for what veterinary science now recognizes as a number of different diseases with high morbidity and mortality, such as rinderpest, erysipelas, foot-and-mouth disease, anthrax, and streptococcus infections. Some of these livestock diseases can also affect humans. The term "murrain" also referred to an epidemic of such a disease. There were major sheep- and cattle-murrains in Europe during the 14th century, which, combined with the Little Ice Age, resulted in the Great Famine of 1315–1317, weakening the population of Europe before the onset of the Blac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andean Geology
''Andean Geology'' (formerly ''Revista Geológica de Chile'') is a peer-reviewed scientific journal published three times per year by the National Geology and Mining Service, Chile's geology and mining agency. The journal covers the field of geology and related earth sciences, primarily on issues that are relevant to South America, Central America, and Antarctica with a particular focus on the Andes. The journal was established in 1974 and articles are published in English and Spanish. The editor-in-chief is Daniel Bertin (National Geology and Mining Service). Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 2.368. Reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth-Science Reviews
''Earth-Science Reviews'' is a monthly peer-reviewed scientific journal published by Elsevier. It covers all aspects of Earth sciences. The editors-in-chief for this journal are A. Chin, C. Doglioni, J.L. Florsheim, M.F.J. Flower, G.R. Foulger, A. Gómez-Tuena, S. Khan, S. Marriott, A.D. Miall, G.F. Panza, J.A. Sanchez-Cabeza, M. Strecker, E.S. Takle, M. Widdowson, and P.B. Wignall. Abstracting and indexing This journal is abstracted and indexed by: According to the ''Journal Citation Reports'', the journal has a 2012 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 7.339. References External links {{Authority control Earth and atmospheric sciences journals Elsevier academic journals English-language journals Monthly journals Academic journals esta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placer Deposit
In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish language, Spanish word ''placer'', meaning "alluvium, alluvial sand". Placer mining is an important source of gold, and was the main technique used in the early years of many gold rushes, including the California Gold Rush. Types of placer deposits include alluvium, eluvium, beach placers, aeolian placers and paleo-placers. Placer materials must be both dense and resistant to weathering processes. To accumulate in placers, mineral particles must have a specific gravity above 2.58. Placer environments typically contain black sand, a conspicuous shiny black mixture of iron oxides, mostly magnetite with variable amounts of ilmenite and hematite. Valuable mineral components often occurring with black sands are monazite, rutile, zircon, chromite, wolframite, and cassiterite. Early mining opera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactivity (chemistry), reactive chemical elements, being the second-lowest in the reactivity series. It is solid under standard temperature and pressure, standard conditions. Gold often occurs in free elemental (native state (metallurgy), native state), as gold nugget, nuggets or grains, in rock (geology), rocks, vein (geology), veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as in electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magallanes Region
The Magallanes Region (), officially the Magallanes y la Antártica Chilena Region () or Magallanes and the Chilean Antarctica Region in English, is one of Chile's 16 first order administrative divisions. It is the southernmost, largest, and second least populated Regions of Chile, region of Chile. It comprises four provinces of Chile, provinces: Última Esperanza Province, Última Esperanza, Magallanes Province, Magallanes, Tierra del Fuego Province, Chile, Tierra del Fuego, and Antártica Chilena. The region takes its name from the Strait of Magellan which runs through it, which was in turn named after Ferdinand Magellan, the leader of the European expedition that discovered it. Magallanes's geographical features include Torres del Paine, Cape Horn, Tierra del Fuego island, and the Strait of Magellan. It also includes the Chilean Antarctic Territory, Antarctic territory claimed by Chile. Despite its large area, much of the land in the region is rugged or closed off for sheep f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musala
Musala ( ); from Arabic through Ottoman Turkish: from '' Musalla'', "near God" or "place for prayer" is the highest peak in the Rila Mountains, as well as in Bulgaria and the entire Balkan Peninsula, standing at . With a topographic prominence of , Musala is also the 6th highest peak by topographic prominence in mainland Europe. It is also the 3rd most topographically isolated major peak in Continental Europe. Musala is situated within the Rila National Park, which is noted for its rich flora, including species such as Macedonian Pine and Bulgarian Fir in the forests on its middle slopes, and fauna; it is one of the easiest places in Europe to see the wallcreeper. All major mountain ranges of Bulgaria can be seen from the top; these include Vitosha to the northwest, Sredna Gora towards the northeast, the Balkan Mountains along most of the northern horizon behind Vitosha and Sredna Gora, the Rhodope Mountains to the southeast, Pirin to the south, Osogovo and Ruy Mountai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocky Mountain National Park
Rocky Mountain National Park is a List of national parks of the United States, national park of the United States located approximately northwest of Denver in north-central Colorado, within the Front Range of the Rocky Mountains. The park is situated between the towns of Estes Park, Colorado, Estes Park to the east and Grand Lake, Colorado, Grand Lake to the west. The eastern and western slopes of the Continental Divide of the Americas, Continental Divide run directly through the center of the park with the headwaters of the Colorado River located in the park's northwestern region. The main features of the park include mountains, alpine lakes and a wide variety of wildlife within various climates and environments, from wooded forests to mountain tundra. The Rocky Mountain National Park Act was signed by President Woodrow Wilson on January 26, 1915, establishing the park boundaries and protecting the area for future generations. The Civilian Conservation Corps built the main aut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
