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Moldavite
Moldavite ( cs, vltavín) is a forest green, olive green or blue greenish vitreous silica projectile glass formed by a meteorite impact in southern Germany (Nördlinger Ries Crater) that occurred about 15 million years ago. It is a type of tektite. Early studies Moldavite was introduced to the scientific public for the first time in 1786 as "chrysolites" from Týn nad Vltavou in a lecture by Josef Mayer of Prague University, read at a meeting of the Bohemian Scientific Society (Mayer 1788). Zippe (1836) first used the term "moldavite", derived from the Moldau (Vltava) river in Bohemia (the Czech Republic), from where the first described pieces came. Origin In 1900, Franz Eduard Suess pointed out that the gravel-size moldavites exhibited curious pittings and wrinkles on the surface, which could not be due to the action of water, but resembled the characteristic markings on many meteorites. He attributed the material to a cosmic origin and regarded moldavites as a special type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tektite
Tektites (from grc, τηκτός , meaning 'molten') are gravel-sized bodies composed of black, green, brown or grey natural glass formed from terrestrial debris ejected during meteorite impacts. The term was coined by Austrian geologist Franz Eduard Suess (1867–1941), son of Eduard Suess. They generally range in size from millimetres to centimetres. Millimetre-scale tektites are known as microtektites.French, B. M. (1998) ''Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures.'' LPI Contribution No. 954. Lunar and Planetary Institute, Houston, Texas. 120 pp.McCall, G. J. H. (2001) ''Tektites in the Geological Record: Showers of Glass from the Sky.'' The Geological Society Publishing House, Bath, United Kingdom. 256 pp. Montanari, A., and C. Koeberl (2000) ''Impact Stratigraphy. The Italian Record.'' Lecture Notes in Earth Sciences Series no. 93. Springer-Verlag, New York, New York. 364 pp. Tektites are characterized by: # ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moldau (river)
Vltava ( , ; german: Moldau ) is the longest river in the Czech Republic, running southeast along the Bohemian Forest and then north across Bohemia, through Český Krumlov, České Budějovice and Prague, and finally merging with the Labe at Mělník. It is commonly referred to as the "Czech national river". Both the Czech name ' and the German name ' are believed to originate from the old Germanic words ' 'wild water' (compare Latin '). In the ' (872 AD) it is called '; from 1113 AD it is attested as '. In the ' (1125 AD) it is attested for the first time in its Bohemian form, '. Course The Vltava River is long and drains an area of in size, over half of Bohemia and about a third of the Czech Republic's entire territory. As it runs through Prague, the river is crossed by 18 bridges (including the Charles Bridge) and covers within the city. The water from the river was used for drinking until 1912 when the Vinohrady Water Tower ceased pumping operations. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) due to different numbers of neutrons in their nuclei. While all isotopes of a given element have almost the same chemical properties, they have different atomic masses and physical properties. The term isotope is formed from the Greek roots isos ( ἴσος "equal") and topos ( τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table. It was coined by Scottish doctor and writer Margaret Todd in 1913 in a suggestion to the British chemist Frederick Soddy. The number of protons within the atom's nucleus is called its atomic number and is equal to the number of electrons in the neutral (non-ionized) atom. Each atomic numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beryllium-10
Beryllium-10 (10Be) is a radioactive isotope of beryllium. It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen. Beryllium-10 has a half-life of 1.39 × 106 years, and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV. It decays through the reaction 10Be→10B + e−. Light elements in the atmosphere react with high energy galactic cosmic ray particles. The spallation of the reaction products is the source of 10Be (t, u particles like n or p): :14N(t,5u)10Be; Example: 14N(n,p α)10Be :16O(t,7u)10Be Because beryllium tends to exist in solutions below about pH 5.5 (and rainwater above many industrialized areas can have a pH less than 5), it will dissolve and be transported to the Earth's surface via rainwater. As the precipitation quickly becomes more alkaline, beryllium drops out of solution. Cosmogenic 10Be thereby accumulates at the soil surface, where its relatively long half-life (1.387 million years) permi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australite
Australites are tektites found in Australia. They are mostly dark or black, and have shapes including discs and bowls that are not seen in other tektites. NASA used the shape of "flanged button" australites in designing re-entry modules for the Apollo program in the 1960s. History Indigenous Australians termed australites ''ooga'' ("staring eyes"), and they were used as sacred objects or as cutting tools. Europeans found out about australites in 1857, when explorer Thomas Mitchell gave naturalist Charles Darwin a mysteriously shaped piece of natural black glass. Darwin thought that australites were of volcanic origin due to their similarity to obsidian, volcanic glass. Later, australites were called ''blackfellows' buttons'' and ''obsidian bombs''. One of the first scientists to seriously study australites was Charles Fenner, who saw his first australite in 1907. He believed that australites were glass meteorites. Origin Early theories about the source of australites included v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
České Budějovice Basin
The České Budějovice Basin ( cs, Českobudějovická pánev) is a geomorphological mesoregion of the Czech Republic. It is located in the South Bohemian Region and it is named after the city of České Budějovice. It is known as a cultural landscape with numerous ponds. Geomorphology The České Budějovice Basin is one of the mesoregions of the South Bohemian Basins (the second being the Třeboň Basin) within the Bohemian Massif. It is further subdivided into the microregions of Putim Basin and Blata Basin. The basin is a tectonic depression limited mostly by distinctive fault slopes, filled with slightly undulating to flat relief at a height of 380–410 m above sea level, which is the result of erosion and denudation processes after the emptying of lakes in the Neogene. There are no significant peaks in the area. The highest hill is Vráže at above sea level, in the southern part of the territory. In the north there are the hills Skalský vrch at and Na Zámku at . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Třeboň Basin
The Třeboň Basin ( cs, Třeboňská pánev) is a geomorphological mesoregion of the Czech Republic. It is located in the South Bohemian Region and it is named after the town of Třeboň. It is known for its fishpond system. Geomorphology The Třeboň Basin is one of the mesoregions of the South Bohemian Basins (the second being the České Budějovice Basin) within the Bohemian Massif. It is further subdivided into the microregions of Lišov Threshold, Lomnice Basin and Kardašova Řečice Uplands. Relief varies across the territory. In the middle the relief is flat, in the east there is a flat hilly relief, and in the west there is an asymmetrical ridge with a rugged hilly relief. The highest part of the territory is the western part, in Lišov Threshold, where altitudes are above . There is also the highest peak of the territory, Baba at above sea level. Geology The Třeboň Basin was tectonically formed during the Cretaceous. It is filled with sediments from the Late Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domanín (Jindřichův Hradec District)
Domanín is a municipality and village in Jindřichův Hradec District in the South Bohemian Region of the Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The .... It has about 400 inhabitants. References External links * Villages in Jindřichův Hradec District {{SouthBohemia-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vrábče
Vrábče (german: Prabsch) is a municipality and village in České Budějovice District in the South Bohemian Region of the Czech Republic. It has about 800 inhabitants. Vrábče lies approximately south-west of České Budějovice and south of Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate .... Administrative parts Villages of Koroseky, Kroclov and Slavče are administrative parts of Vrábče. References Villages in České Budějovice District {{SouthBohemia-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lusatia
Lusatia (german: Lausitz, pl, Łużyce, hsb, Łužica, dsb, Łužyca, cs, Lužice, la, Lusatia, rarely also referred to as Sorbia) is a historical region in Central Europe, split between Germany and Poland. Lusatia stretches from the Bóbr and Kwisa rivers in the east to the Pulsnitz and Black Elster rivers in the west, and is located within the German states of Saxony and Brandenburg as well as in the Polish voivodeships of Lower Silesia and Lubusz. Lusatia's central rivers are the Spree and the Lusatian Neisse, which constitutes the border between Germany and Poland since 1945 (Oder–Neisse line). The Lusatian Mountains (part of the Sudetes), separate Lusatia from Bohemia (Czech Republic) in the south. Lusatia is traditionally divided into Upper Lusatia (the hilly southern part) and Lower Lusatia (the flat northern part). The areas east and west along the Spree in the German part of Lusatia are home to the Slavic Sorbs, one of Germany's four officially recognized indige ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
