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Dreiser Weiher
The Dreiser Weiher near Dreis-Brück in the vicinity of Daun in the German state of Rhineland-Palatinate is a tub-shaped maar in the Eifel mountains. It is up to 1,360 metres long and 1,160 metres wide. It is the second largest maar in the Eifel. Formation The dry maar is located on a hillside and belongs to the Quaternary volcanoes of the West Eifel. It is surrounded by a crater rim of between 36 and 120 metres high. From the analysis of volcanic tufff, which were ejected from the maar during an eruption, and from geomagnetic measurements, five tuff fields and four volcanic centres on the edge of the bowl were identified. In the centre of the maar an eruption site was identified, hence the maar is probably an eruption funnel. The tuffs of the Dreiser Weiher lies above the depositions of the surrounding volcanoes, the maar is thus younger than the others. An exact date for the formation of the maars using pollen analysis could not be done for the Dreiser Weiher since there is no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dreiser Weiher 001x
Theodore Herman Albert Dreiser (; August 27, 1871 – December 28, 1945) was an American novelist and journalist of the naturalism (literature), naturalist school. His novels often featured main characters who succeeded at their objectives despite a lack of a firm moral code, and literary situations that more closely resemble studies of nature than tales of choice and agency (philosophy), agency. Dreiser's best known novels include ''Sister Carrie'' (1900) and ''An American Tragedy'' (1925). Early life Dreiser was born in Terre Haute, Indiana, to John Paul Dreiser and Sarah Maria (née Schanab).Finding aid to thTheodore Dreiser papersat thUniversity of Pennsylvania Libraries/ref> John Dreiser was a Germans, German immigrant from Mayen in the Rhine Province of Prussia, and Sarah was from the Mennonite farming community near Dayton, Ohio. Her family disowned her for converting to Catholic Church, Roman Catholicism in order to marry John Dreiser. Theodore was the twelfth of thirteen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomagnetic
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo. The magnitude of Earth's magnetic field at its surface ranges from . As an approximation, it is represented by a field of a magnetic dipole currently tilted at an angle of about 11° with respect to Earth's rotational axis, as if there were an enormous bar magnet placed at that angle through the center of Earth. The North geomagnetic pole actually represents the South pole of Earth's magnetic field, and conversely the South geomagnetic pole corresponds to the north pole of Earth's magnetic f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraglider
Paragliding is the recreational and competitive adventure sport of flying paragliders: lightweight, free-flying, foot-launched glider aircraft with no rigid primary structure. The pilot sits in a harness or lies supine in a cocoon-like 'pod' suspended below a fabric wing. Wing shape is maintained by the suspension lines, the pressure of air entering vents in the front of the wing, and the aerodynamic forces of the air flowing over the outside. Despite not using an engine, paraglider flights can last many hours and cover many hundreds of kilometres, though flights of one to two hours and covering some tens of kilometres are more the norm. By skillful exploitation of sources of lift, the pilot may gain height, often climbing to altitudes of a few thousand metres. History In 1966, Canadian Domina Jalbert was granted a patent for a ''multi-cell wing type aerial device—''"a wing having a flexible canopy constituting an upper skin and with a plurality of longitudinally exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nürburg Spring
Nürburg () is a town in the German district of Ahrweiler, in the state of Rhineland-Palatinate. It is also the name of the local castle, Nürburg Castle, which was built in the High Middle Ages. The name is derived from Latin ''niger'', meaning "black", and High German ''burg'', meaning "castle". The castle is made of basalt which usually has black color. The well-known racing track Nürburgring is nearby. Location The Nürburg rises above the village of the same name on the second-highest hill in the Eifel (). The castle and hill are regarded as a characteristic feature of the Eifel. Even though it is one of the most significant castles in the Eifel, it nevertheless still needs to be researched in full. There are almost no written sources relating to the history of the castle's construction in the Middle Ages. The hill is referred to in documentary evidence in 954 by the name ''mone nore'', which means black hill. In descriptions of boundaries which served to clarify which pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Spring
Mineral springs are naturally occurring springs that produces hard water, water that contains dissolved minerals. Salts, sulfur compounds, and gases are among the substances that can be dissolved in the spring water during its passage underground. In this they are unlike sweet springs, which produce soft water with no noticeable dissolved gasses. The dissolved minerals may alter the water's taste. Mineral water obtained from mineral springs, and the precipitated salts such as Epsom salt have long been important commercial products. Some mineral springs may contain significant amounts of harmful dissolved minerals, such as arsenic, and should not be drunk. Sulfur springs smell of rotten eggs due to hydrogen sulfide (H2S), which is hazardous and sometimes deadly. It is a gas, and it usually enters the body when it is breathed in. The quantities ingested in drinking water are much lower and are not considered likely to cause harm, but few studies on long-term, low-level e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maar Lake
A maar is a broad, low- relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow crater lake which may also be called a maar. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany. Notes: * According to German Wikipedia's ''"Maar"'' article, in 1544 in his book ''Cosmographia'', Sebastian Münster (1488–1552) first applied the word "maar" (as ''Marh'') to the Ulmener Maar and the Laacher See. See: Sebastian Münster, ''Cosmographia'' (Basel, Switzerland: Heinrich Petri, 1544)p. 341. From p. 341: ''"Item zwen namhafftiger seen seind in der Eyfel / einer bey de schloß Ulmen / und ein ander bey dem Closter züm Laich / die seind sere tieff / habe kein ynflüß aber vil außflüß / die nennet man Marh unnd seind fischreich."'' (Also two noteworthy lakes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magmatic Differentiation
In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. The sequence of (usually increasingly silicic) magmas produced by igneous differentiation is known as a magma series. Definitions Primary melts When a rock melts to form a liquid, the liquid is known as a ''primary melt''. Primary melts have not undergone any differentiation and represent the starting composition of a magma. In nature, primary melts are rarely seen. Some leucosomes of migmatites are examples of primary melts. Primary melts derived from the mantle are especially important and are known as ''primitive melts'' or primitive magmas. By finding the primitive magma composition of a magma series, it is possible to model the composition of the rock from which a melt was formed, which is important because we have little direct evidence of the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Mantle
Earth's mantle is a layer of silicate rock between the crust and the outer core. It has a mass of 4.01 × 1024 kg and thus makes up 67% of the mass of Earth. It has a thickness of making up about 84% of Earth's volume. It is predominantly solid but, on geologic time scales, it behaves as a viscous fluid, sometimes described as having the consistency of caramel. Partial melting of the mantle at mid-ocean ridges produces oceanic crust, and partial melting of the mantle at subduction zones produces continental crust. Structure Rheology Earth's mantle is divided into two major rheological layers: the rigid lithosphere comprising the uppermost mantle, and the more ductile asthenosphere, separated by the lithosphere-asthenosphere boundary. Lithosphere underlying ocean crust has a thickness of around 100 km, whereas lithosphere underlying continental crust generally has a thickness of 150–200 km. The lithosphere and overlying crust make up tectonic plates, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunite
Dunite (), also known as olivinite (not to be confused with the mineral olivenite), is an intrusive igneous rock of ultramafic composition and with phaneritic (coarse-grained) texture. The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite, magnetite, and pyrope. Dunite is the olivine-rich endmember of the peridotite group of mantle-derived rocks. Dunite and other peridotite rocks are considered the major constituents of the Earth's mantle above a depth of about . Dunite is rarely found within continental rocks, but where it is found, it typically occurs at the base of ophiolite sequences where slabs of mantle rock from a subduction zone have been thrust onto continental crust by obduction during continental or island arc collisions ( orogeny). It is also found in alpine peridotite massifs that represent slivers of sub-continental mantle exposed during collisional orogeny. Dunite typically undergoes retr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen Analysis
Palynology is the "study of dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and ''-logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposits including sediments of any age. The condition and identification of those particles, organic and inorganic, give the palynologist clues to the life, environment, and energetic conditions that produced them. The term is commonly used to refer to a subset of the discipline, which is defined as "the study of microscopic objects of macromolecular organic composition (i.e., compounds of carbon, hydrogen, nitrogen and oxygen), not capable of dissolution in hydrochloric or hydrofluoric acids". It is the science that studies contemporary and fossil palynomorphs (paleopalynology), including pollen, spores, orbicules, dinocysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter (POM) and kerogen found in sedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, ''tuffaceous sandstone''). Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa in guidebooks and in television programmes. Volcanic ash The material that is expelled in a vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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