The territory of Nicaragua is part of one of the most geologically unstable and “youngest” areas on Earth, the Central American isthmus, whose structure began to take shape in the Miocene allowing the union of the two American subcontinents thanks above all to the intense volcanic activity connected with the great orogeny that led to the formation of the mighty mountain ranges along the entire edge of the Pacific. Nicaragua actually hosts the most characteristic structural element of the isthmus, the “great depression”, a wide tectonic groove that can be considered as the authentic physical border between the North American and South American worlds; it also represents a fundamental dividing element for Nicaragua, which separates it into two very different areas in terms of extension, geomorphology and population. Over 2/3 of the entire territory of Nicaragua, the region located between the rift valley and the Caribbean coast is part of the so-called Antillan area,it extends, through a large ridge under the Antillean Sea, to form the backbone of the reliefs of Jamaica, Haiti and Puerto Rico; it is mainly made up of granite and metamorphic Precambrian formations, partially covered by Mesozoic sediments and Cenozoic effusive rocks, in particular basalts and andesites. Neozoic alluvial deposits make up the vast coastal plain, known as Costa de Mosquitos, which overlooks the Sea of ​​the Antilles, with a monotonous course, presenting low, importuous coasts bordered by lagoons. Towards the interior, beyond a band of low hills, the territory presents a series of plateaus deeply engraved by erosion and dominated by some ridges (Cordillera Isabelia, Serranías Huapí, Cordillera Chontalena, etc.), arranged in a fan shape from W to E, according to the typical trend of the Antillean region; some peaks (Kilambé, Penas Blancas) exceed 1700 m and Cerro Mogotón reaches 2107 meters. Completely different is the environment of western Nicaragua, between the great depression and the Pacific coasts, clear evidence of the violent and prolonged volcanic activity that accompanied the birth of the American mountain ranges and which still persists, albeit to a lesser extent: the connection between the two continental blocks (until the beginning of the Neozoic era North and South America were divided by the sea as the entire Nicaraguan depression was submerged by water) was precisely due to the enormous mass of lava erupted especially in the course of the Miocene and the powerful debris layers fed by the meteoric degradation of the newly emerged reliefs. The Great Nicaraguan Depression, ca. 600 km and partially occupied by the lake basins huge mass of lava erupted especially during the Miocene and the powerful debris layers fed by the meteoric degradation of the newly emerged reliefs. The Great Nicaraguan Depression, ca. 600 km and partially occupied by the lake basins huge mass of lava erupted especially during the Miocene and the powerful debris layers fed by the meteoric degradation of the newly emerged reliefs. According to simplyyellowpages, Nicaragua is a country in Central America. The Great Nicaraguan Depression, ca. 600 km and partially occupied by the lake basins Managua and Nicaragua, was formed with the concurrence of different and contrasting phenomena, tectonic, volcanic, seismic, erosive and constructive; delineated in the Pleistocene with the formation of subparallel fault systems and the consequent sinking of the intervening plates, diagonally cuts the isthmus from NW to SE, from the Gulf of Fonseca on the Pacific (submerged portion of the same depression, once joined directly to Lake Managua) at the furrow of the San Juan River, on the Sea of ​​the Antilles. The so-called Marrabios line up between the extremely narrow Pacific coastal selvedge and the rift valley, about twenty volcanoes that arose during the Neozoic era in relation to the formation of the great depression; the most recent, Cerro Negro (350 m), dates back to just 1850. From Lake Nicaragua rise the twin cones of the Concepción and Maderas volcanoes which, joined by an isthmus, form the island of Ometepe, the largest in Nicaragua, and that of Zapatera, in the homonymous island; on the northwestern shore of the same lake rises the volcanic edifice of Mombacho above Granada. The best known volcano in Nicaragua, Momotombo, responsible for violent eruptions such as those of 1870 and 1886 which reduced it from the previous over 1600 m to the current 1280 m, rises to the N of Lake Managua, flanked by the smaller Momotombito emerging from the waters of the lake. Other notable volcanoes are the Chonco, San Cristóbal (or El Viejo or Chinandega; 1745m, the highest volcano in Nicaragua), Rota, Hoyo, etc. The vast caldera, with a diameter of approx. 1 km, eloquent testimony of the terrifying explosion that in 1835 tore apart the building of the Cosigüina volcano: the shock was felt thousands of kilometers away and showers of ashes fell within a radius of 1200 km. In Nicaragua, earthquakes are frequent and often disastrous, such as those that hit the capital in 1931 and 1972, practically reducing it to a heap of ruins. eloquent testimony of the terrifying explosion that in 1835 tore apart the building of the Cosigüina volcano: the shock was felt thousands of kilometers away and showers of ashes fell within a radius of 1200 km. In Nicaragua, earthquakes are frequent and often disastrous, such as those that hit the capital in 1931 and 1972, practically reducing it to a heap of ruins. eloquent testimony of the terrifying explosion that in 1835 tore apart the building of the Cosigüina volcano: the shock was felt thousands of kilometers away and showers of ashes fell within a radius of 1200 km. In Nicaragua, earthquakes are frequent and often disastrous, such as those that hit the capital in 1931 and 1972, practically reducing it to a heap of ruins.