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Holzmaar01
The Holzmaar lies in the Volcanic Eifel in the German state of Rhineland-Palatinate almost halfway between Gillenfeld (2.5 km away to the southwest) and Eckfeld. The maar has an area of about , a diameter of and a depth of and lies within a nature reserve, almost completely surrounded by woods. It is one of the two maars making up the Gillenfeld Maars, the other being the Pulvermaar. The Holzmaar is fed by a headstream of the Sammetbach which crosses the maar. In the immediate vicinity is another maar, the Dürres Maar. On its south and southwest shores, the maar has silted up with sediments, core samples from which give a comprehensive picture of the climate going back to the last cold period. The sediments of the Holzmaar go back 23,200 years. This assessment was made possible by comparing the sequence and radiometric dating obtained in the maar basin with that of the Meerfelder Maar. The time of the maximum of the last glaciation derived from varve chronology is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holzmaar01
The Holzmaar lies in the Volcanic Eifel in the German state of Rhineland-Palatinate almost halfway between Gillenfeld (2.5 km away to the southwest) and Eckfeld. The maar has an area of about , a diameter of and a depth of and lies within a nature reserve, almost completely surrounded by woods. It is one of the two maars making up the Gillenfeld Maars, the other being the Pulvermaar. The Holzmaar is fed by a headstream of the Sammetbach which crosses the maar. In the immediate vicinity is another maar, the Dürres Maar. On its south and southwest shores, the maar has silted up with sediments, core samples from which give a comprehensive picture of the climate going back to the last cold period. The sediments of the Holzmaar go back 23,200 years. This assessment was made possible by comparing the sequence and radiometric dating obtained in the maar basin with that of the Meerfelder Maar. The time of the maximum of the last glaciation derived from varve chronology is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitsche Maar
The Hitsche Maar lies in the Eifel Mountains between Bitburg and Ulmen. The maar has a diameter of 60 metres and a crater depth of 5 metres. Known as the "smallest maar in the Eifel", the Hitsche has silted up to form a sedge marsh. Name The name of the maar, which is often shortened to ''Die Hitsche'' but also called the ''Hetsche'', ''Hättsche'', or ''Hütsche'', probably derives from the local dialect word for "toad". Formation The Hitsche Maar is a dry maar and lies west of the Alf valley in a group of volcanoes and two other maars: the Holzmaar and the Dürres Maar. Like the other two, it lies along the geological fault line running from northwest to southeast caused by volcanic activity during the Weichselian glaciation and, with an age of over 20,000 years, is the oldest of these maars. The 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 soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core Sample
A core sample is a cylindrical section of (usually) a naturally-occurring substance. Most core samples are obtained by drilling with special drills into the substance, such as sediment or rock, with a hollow steel tube, called a core drill. The hole made for the core sample is called the "core hole". A variety of core samplers exist to sample different media under different conditions. More continue to be invented on a regular basis. In the coring process, the sample is pushed more or less intact into the tube. Removed from the tube in the laboratory, it is inspected and analyzed by different techniques and equipment depending on the type of data desired. Core samples can be taken to test the properties of manmade materials, such as concrete, ceramics, some metals and alloys, especially the softer ones. Core samples can also be taken of living things, including human beings, especially of a person's bones for microscopic examination to help diagnose diseases. Methods The compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maars Of The Eifel
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 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bogs Of Rhineland-Palatinate
A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; alkaline mires are called fens. A baygall is another type of bog found in the forest of the Gulf Coast states in the United States.Watson, Geraldine Ellis (2000) ''Big Thicket Plant Ecology: An Introduction'', Third Edition (Temple Big Thicket Series #5). University of North Texas Press. Denton, Texas. 152 pp. Texas Parks and Wildlife. Ecological Mapping systems of Texas: West Gulf Coastal Plain Seepage Swamp and Baygall'. Retrieved 7 July 2020 They are often covered in heath or heather shrubs rooted in the sphagnum moss and peat. The gradual accumulation of decayed plant material in a bog functions as a carbon sink. Bogs occur where the water at the ground surface is acidic and low in nutrients. In contrast to fens, they derive most of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland Ice Core Project
The Greenland Ice Core Project (GRIP) was a research project organised through the European Science Foundation (ESF). The project ran from 1989 to 1995, with drilling seasons from 1990 to 1992. In 1988, the project was accepted as an ESF-associated program, and in the summer of 1989, the fieldwork was started in Greenland. GRIP aimed to collect and investigate 3000-metre-long ice cores drilled at the apex of the Greenland ice sheet, also known as Summit Camp. The Greenland ice sheet comprises more than 90% of the total ice sheet and glacier ice outside Antarctica. The project was managed by a Steering Committee of the University of Bern's Physics Institute, chaired by Professor Bernhard Stauffer. Funding came from eight European nations (Belgium, Denmark, France, Germany, Iceland, Italy, Switzerland, and United Kingdom), and from the European Union. Studies of nuclear isotopes and various atmospheric constituents provided by the cores allowed the team to construct detailed rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland Ice Sheet Project
The Greenland Ice Sheet Project (GISP) was a decade-long project to drill ice cores in Greenland that involved scientists and funding agencies from Denmark, Switzerland and the United States. Besides the U.S. National Science Foundation (NSF), funding was provided by the Swiss National Science Foundation and the Danish Commission for Scientific Research in Greenland. The ice cores provide a proxy archive of temperature and atmospheric constituents that help to understand past climate variations. The preliminary GISP field work started in 1971 at Dye 3 (), where a 372 meter deep, 10.2 cm diameter core was recovered. After this, annual field expeditions were carried out to drill intermediate depth cores at various locations on the ice sheet. The first was a 398 m core at Milcent and another was a 405 m core at the Crete station in 1974. After working out various logistical and engineering problems related to the development of a more sophisticated drilling rig, drilling to bed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varve
A varve is an annual layer of sediment or sedimentary rock. The word 'varve' derives from the Swedish word ''varv'' whose meanings and connotations include 'revolution', 'in layers', and 'circle'. The term first appeared as ''Hvarfig lera'' (varved clay) on the first map produced by the Geological Survey of Sweden in 1862. Initially, "varve" referred to each of the separate components comprising a single annual layer in glacial lake sediments, but at the 1910 Geological Congress, the Swedish geologist Gerard De Geer (1858–1943) proposed a new formal definition, where varve means the whole of any annual sedimentary layer. More recently introduced terms such as 'annually laminated' are synonymous with varve. Of the many rhythmites in the geological record, varves are one of the most important and illuminating in studies of past climate change. Varves are amongst the smallest-scale events recognised in stratigraphy. An annual layer can be highly visible because the particles wash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meerfelder Maar
The Meerfelder Maar is a maar by the village of Meerfeld not far from the town of Manderscheid in the Eifel in the German state of Rhineland-Palatinate. Formation The maar is at least 30,000 years old and, according to the more recent information, is probably even 40,000 years old. In 1978 the lake deposits were investigated in order to determine its exact age. Numerous borings have been carried out in the Meerfelder Maar right up to the present day. It was formed by a huge underground phreatomagmatic explosion that happened when hot magma rose and struck a water-laden layer of rock. The explosive evaporation of the water crushed the surrounding rock and threw some of it upwards. The resulting hollow filled up again with rock and a funnel-shaped sink-hole formed at the surface. The magma chamber, from which the magma rose, lies about 2,000 to 6,000 metres below the Meerfelder Maar. Structure The whole crater has a diameter of 1,400 metres from east to west and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric Dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of Earth itself, and can also be used to date a wide range of natural and man-made materials. Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale. Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating. By al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weichselian Glaciation
The Weichselian glaciation was the last glacial period and its associated glaciation in northern parts of Europe. In the Alpine region it corresponds to the Würm glaciation. It was characterized by a large ice sheet (the Fenno-Scandian ice sheet) that spread out from the Scandinavian Mountains and extended as far as the east coast of Schleswig-Holstein, northern Poland and Northwest Russia. This glaciation is also known as the Weichselian ice age (german: Weichsel-Eiszeit), Vistulian glaciation, Weichsel or, less commonly, the Weichsel glaciation, Weichselian cold period (''Weichsel-Kaltzeit''), Weichselian glacial (''Weichsel-Glazial''), ''Weichselian Stage'' or, rarely, the Weichselian complex (''Weichsel-Komplex''). In Northern Europe it was the youngest of the glacials of the Pleistocene ice age. The preceding warm period in this region was the Eemian interglacial. The last cold period began about 115,000 years ago and ended 11,700 years ago. Its end corresponds with the end o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulvermaar
The Pulvermaar is a water-filled maar that lies southeast of Daun in the German state of Rhineland-Palatinate. Together with the Holzmaar it is one of the Gillenfeld maars. Description A tuff site in the bog formations of the neighbouring Strohner Maar is ascribed to the Pulvermaar and is therefore older than the Pulvermaar. Early pollen analyses of the bogs gave an age for the tuff site – and thus the Pulvermaar – of about 10,050 years. More recent studies show, however, underwater terraces at greater depth as well as ice wedges inside the tephra deposits, both of which suggest that the maar was formed during the last ice age, 20,000 to 30,000 years ago. Vulcanologists from the Smithsonian Institution estimate the last eruption of the Strohner Maar and Pulvermaar in 8,300 BC. The almost circular maar has steep funnel-shaped sides. The maar lake lies at a height of and, with a maximum depth of , is the deepest in the Volcanic Eifel. It has a diameter of about and surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
