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Pantasma is a region in the north of Nicaragua. In the Miskito language the word ''Pantasma'' means ''small humans'' or ''flat head''. The Spanish word ''Fantasma'' (Galego: ''(Pantasma )'') origins from the Greek ''Phantasma'' and means ''ghost''. The (Valle de Pantasma ), also called the "Crater of Pantasma", is a circular valley over 12 km in diameter situated in Nicaragua. It is passed by the Rio Pantasma, a tributary of the Rio Coco (also called Rio Segovia). In its center lies the village of Las Praderas, the principal place of the community of (Santa Maria de Pantasma ) with about 40,000 inhabitants in the province of Jinotega. In the poor, but fertile and agricultural intensely used valley corn, grain, fruit, and coffee are cultivated and cattle is bred. The town is the site of one of the most famous actions of the civil war between the Sandinista government and the rebel Contras. On October 18, 1983, the Nicaraguan Democratic Force's Task Force Diriangén, under Comandante "Mike Lima," launched a (surprise attack ) on the town, overrunning a battalion headquarters, detonating a munitions depot, robbing a state bank, and destroying a police station, a school, and all other government offices and facilities, leaving 47 defenders and residents dead. Though a military success, politically the Sandinistas depicted the assault as a "massacre" and a symbol of rebel atrocities. ==Impact crater hypothesis== Some have speculated that the Crater of Pantasma was formed when an over 500 m large meteorite struck into the Tertiary effusive layers of the volcanic mountains in the north of Nicaragua. The circular shape of the crater, the skew of its floor according to the spacious mountain slope and its apparently arbitrary situation supports the thesis of a meteorite impact. A central uplift is missing or may already be covered with sediments. An ejection ring is not recognizable clearly in the rough landscape. The size and the shape of the crater remind at the 10 km large and about one million years old crater of Lake Bosumtwi in Ghana. Its embedding into the landscape is nearly identical to the impact crater of Goat Paddock in Australia (5 km, up to 50 million years). The volcanic history of the whole region and the neighbourhood of an active volcanic zone suggest a volcanic origin, but don't prove it conclusively. A search for typical impact material (shatter cones, suevites, tektites), that could prove an impact event, has yet to take place. Based on available observations and data, this site is listed as improbable, or unlikely to be an impact site. But in spite of this an expedition by the Nicaraguan Scientific Association of Astronomers and Astrophysicists (Astronic) to the Pantasma Valley in July 2009 has confirmed the impact hypothesis. Note: The Pantasma valley can not be "triassic" (250 to 200 million years B.C.) because it lies on the caribbean platter, that was formed between 140 and 70 B.C. The fresh look of the crater suggests an age of only up to 1 million years. In 2010, the Geologist Jean H. Cornec from Denver/Col. reportet the detection of a new tektite strewn field (about 800,000 years old!) in western Belize, 300 miles north-west, which could be strongly related to the Pantasma crater. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pantasma」の詳細全文を読む スポンサード リンク
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