|
Laacher See
Laacher See (), also known as Lake Laach or Laach Lake, is a volcanic caldera lake with a diameter of in Rhineland-Palatinate, Germany, about northwest of Koblenz, south of Bonn, and west of Andernach. It is in the Eifel mountain range, and is part of the East Eifel volcanic field within the larger Volcanic Eifel. The lake was formed by a Plinian eruption approximately 13,000 years BP with a Volcanic Explosivity Index (VEI) of 6, on the same scale as the Pinatubo eruption of 1991. Description The lake is oval in shape and surrounded by high banks. The lava was quarried for millstones from the Roman period until the introduction of iron rollers for grinding grain. On the western side lies the Benedictine Maria Laach Abbey ('), founded in 1093 by Henry II of Laach of the House of Luxembourg, first Count Palatine of the Rhine, who had his castle opposite to the monastery above the eastern lakeside. The lake has no natural outlet but is drained by a tunnel dug before 1170 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ahrweiler (district)
Ahrweiler () is a district in the north of Rhineland-Palatinate, Germany. It is bounded by (from the north and clockwise) the districts of Euskirchen, Rhein-Sieg and the city of Bonn in the state of North Rhine-Westphalia, and the districts of Neuwied, Mayen-Koblenz and Vulkaneifel. History The region was conquered by the Romans under Julius Caesar about 50 BC. Some hundred years later the Roman fort of Rigomagus (Gaulish for "king's field") was founded, later to become the city of Remagen. The Vinxtbach, a narrow brook and an affluent of the Rhine, was defined as the borderline between the Roman provinces of Germania superior and Germania inferior. There was originally a Roman villa here; the German suffix, "weiler", is from the Latin term "villare", meaning "land attached to a Roman villa, farm". Portions of a Roman aqueduct have also been found nearby. Many towns were first mentioned in the 9th century, among them Sinzig and the eponymous village of Ahrweiler (since 1969 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich II Of Laach
Henry of Laach (in German: ''Heinrich von Laach'') was the first count palatine of the Rhine (1085/1087–1095). Henry was the son of Herman I, count of Gleiberg. Henry was a follower of Henry IV, Holy Roman Emperor. He had lands in the southeastern Eifel and on the Moselle River. Most of the holdings of Hermann II, Count Palatine fell back to the emperor, when Hermann died without successor. The emperor named Henry count palatine of the Rhine and during the emperor's trip to Italy tasked Henry to hold interim judicial councils. Henry married Herman's widow, Adelaide of Weimar-Orlamünde (d. 1100). From this marriage, Henry may have taken control over some of her holdings along the Moselle. As a consequence, the geographic center of the palatinate moved towards the south. With his wife, Adelaide, Henry founded the Maria Laach Abbey. He was succeeded by his stepson, Siegfried of Ballenstedt Siegfried I of Ballenstedt ( – 9 March 1113), was the son of Adalbert II of Ballensted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromme Culture
The Bromme culture ( da, Brommekultur) is a late Upper Paleolithic culture dated to c. 11,600 to 9,800 cal BC, which corresponds to the second half of the Allerød Oscillation. At this time, reindeer was the most important prey, but the Bromme people also hunted moose/elk, wolverine and beaver. The landscape was a combination of taiga and tundra. The culture is named after a settlement at Bromme on western Zealand, and it is known from several settlements in Denmark and Schleswig-Holstein. In Sweden, it is known from the country's earliest known settlement at Segebro, near Malmö. It is characterized by sturdy lithic flakes that were used for all tools, primarily awls (''{{lang, sv, sticklar''), scrapers, stone axes and tanged points The Bromme culture and the Ahrensburg culture are so similar that it has been proposed that they should be classed as one and the same, under the label Lyngby culture, with the Bromme culture being recognized as an older northern branch of the sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thuringian Basin
The Thuringian Basin (german: Thüringer Becken) is a depression in the central and northwest part of Thuringia in Germany which is crossed by several rivers, the longest of which is the Unstrut. It stretches about from north to south and around from east to west. Its height varies from about 150 to . The Basin is surrounded by a wide outer girdle of limestone (Muschelkalk) ridges (including Hainich, Dün, Hainleite, Hohe Schrecke, Schmücke, Finne), and to the southwest by the Thuringian Forest and to the southeast by sharply divided terraces (the Ilm-Saale and Ohrdruf Muschelkalk plateaus, and the Saale-Elster Bunter sandstone plateau). The Thuringian Basin belongs to the triassic period, during which horizontal beds of Bunter sandstone, Muschelkalk and Keuper were laid down. Below those lie the salt and gypsum layers of Magnesian Limestone (Zechstein). In the Cenozoic era the surrounding ridges were uplifted, whilst the Thuringian Basin sank to form a saucer-shaped depressio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federmesser Culture
''Federmesser'' group is an archaeological umbrella term including the late Upper Paleolithic to Mesolithic cultures of the Northern European Plain, dating to between 14,000 and 12,800 years ago (the late Magdalenian). It is closely related to the Tjongerian culture, as both have been suggested.J.-G. Rozoy, trans. L.G. Strauss, "The (Re-)Population of Northern France between 13,000 and 8000 BP", ''Quaternary International'', Vol. 49j/50 (1998), 69–86, 1998. It includes the ''Tjongerian'' sites at Lochtenrek in the Frisian part of the Netherland, spanning the area of Belgium, the Netherlands, northern France, northern Germany, southern Denmark, and Poland ('' Tarnowian'' and ''Witowian'' cultures). It is also closely related to the Creswellian culture to the west and the Azilian to the south. The name is derived from the characteristic small backed flint blades, in German termed ''Federmesser'' ("quill knife"). It is succeeded by the Ahrensburg culture after 12,800 BP. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they remain as tephra unless hot enough to fuse into pyroclastic rock or tuff. Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. When a volcano explodes, it releases a variety of tephra including ash, cinders, and blocks. These layers settle on the land and, over time, sedimentation occurs incorporating these tephra layers into the geologic record. Often, when a volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Flow
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of but is capable of reaching speeds up to . The gases and tephra can reach temperatures of about . Pyroclastic flows are the most deadly of all volcanic hazards and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Origin of term The word ''pyroclast'' is derived from the Greek (''pýr''), meaning "fire", and (''klastós''), meaning "broken in pieces". A name for pyroclastic flows which glow red in the dark is (French, "burning cloud"); this was notably used to describe the disastrous 1902 eruption of Mount Pelée on Martinique, a French ... [...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] |
Tectonic Plate
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurasian Plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and the area east of the Chersky Range in eastern Siberia. It also includes oceanic crust extending westward to the Mid-Atlantic Ridge and northward to the Gakkel Ridge. The eastern edge is a boundary with the North American Plate to the north and a boundary with the Philippine Sea Plate to the south and possibly with the Okhotsk Plate and the Amurian Plate. The southern edge is a boundary with the African Plate to the west, the Arabian Plate in the middle and the Indo-Australian Plate to the east. The western edge is a divergent boundary with the North American Plate forming the northernmost part of the Mid-Atlantic Ridge, which is straddled by Iceland. All volcanic eruptions in Iceland, such as the 1973 eruption of Eldfell, the 1783 eruptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Plate
The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plate to the west (separated by the Mid-Atlantic Ridge); the Arabian Plate and Somali Plate to the east; the Eurasian Plate, Aegean Sea Plate and Anatolian Plate to the north; and the Antarctic Plate to the south. Between and , the Somali Plate began rifting from the African Plate along the East African Rift. Since the continent of Africa consists of crust from both the African and the Somali plates, some literature refers to the African Plate as the Nubian Plate to distinguish it from the continent as a whole. Boundaries The western edge of the African Plate is a divergent boundary with the North American Plate to the north and the South American Plate to the south which forms the central and southern part of the Mid-Atlantic Ridge. The A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
