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Société Des Mines Et Fonderies De Pontgibaud
The Société des mines et fonderies de Pontgibaud (Pontgibaud Mine & Foundry Company) was a French silver and lead mining and smelting company based in Pontgibaud, Puy-de-Dôme. It mined lead-silver ore deposits that had been exploited since Roman times. Later it opened another factory in Couëron in the Loire estuary, and then closed down the Pontgibaud mines and foundry. The Pontgibaud factory in Couëron diversified into other non-ferrous metal products using imported ore. After being sold and resold it finally closed in 1988. Location Pontgibaud is in the Massif Central on the banks of the Sioule river. The belts of ore extend for about north-south parallel to the course of the Sioule on both sides of Pontgibaud. The silver galena veins are embedded in gneissic rock. The different veins of ore at Pranal, Barbecot, Roure, Les Rosiers, La Miouse and Villevieille are mainly oriented in a north-south direction. The ores are encased in migmatites from the base of the Combrailles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
City
A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agreed definition of the lower boundary for their size. In a narrower sense, a city can be defined as a permanent and Urban density, densely populated place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for housing, transportation, sanitation, Public utilities, utilities, land use, Manufacturing, production of goods, and communication. Their density facilitates interaction between people, government organisations, government organizations, and businesses, sometimes benefiting different parties in the process, such as improving the efficiency of goods and service distribution. Historically, city dwellers have been a small proportion of humanity overall, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalcopyrite
Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a Mohs scale, hardness of 3.5 to 4 on the Mohs scale. Its Streak (mineralogy), streak is diagnostic as green-tinged black. On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). It is rarely found in association with native copper. Chalcopyrite is a conductor of electricity. Copper can be extracted from chalcopyrite ore using various methods. The two predominant methods are pyrometallurgy and hydrometallurgy, the former being the most commercially viable. Etymology The name chalcopyrite comes from the Greek words , which means cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puy De Dôme
Puy de Dôme (, ) is a lava dome and one of the youngest volcanoes in the region of Massif Central in central France. This chain of volcanoes including numerous cinder cones, lava domes and maars is far from the edge of any tectonic plate. Puy de Dôme was created by a Peléan eruption, some 10,700 years ago. It is approximately from Clermont-Ferrand. The Puy-de-Dôme is named after the volcano. History In pre-Christian Europe, Puy de Dôme was an assembly place for spiritual ceremonies. Temples were built at the summit, including a Gallo-Roman temple of Mercury, the ruins of which were discovered in 1872. In 1648, , at the urging of his brother-in-law Blaise Pascal, confirmed Evangelista Torricelli's theory that barometric observations were caused by the weight of air by measuring the height of a column of mercury at three elevations on Puy de Dôme. In 1875, a physics laboratory was built at the summit. Since 1956, a TDF () antenna is also located there. On th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
