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Placer Mining
Placer mining () is the mining of stream bed deposits for minerals. This may be done by open-pit mining or by various surface excavating equipment or tunneling equipment. Placer mining is frequently used for precious metal deposits (particularly gold) and gemstones, both of which are often found in alluvial deposits—deposits of sand and gravel in modern or ancient stream beds, or occasionally glacial deposits. The metal or gemstones, having been moved by stream flow from an original source such as a vein, are typically only a minuscule portion of the total deposit. Since gems and heavy metals like gold are considerably denser than sand, they tend to accumulate at the base of placer deposits. Placer deposits can be as young as a few years old, such as the Canadian Queen Charlotte beach gold placer deposits, or billions of years old like the Elliot Lake uranium paleoplacer within the Huronian Supergroup in Canada. The containing material in an alluvial placer mine may be too lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Sandham - The Cradle
Henry may refer to: People and fictional characters * Henry (given name), including lists of people and fictional characters * Henry (surname) * Henry, a stage name of François-Louis Henry (1786–1855), French baritone Arts and entertainment * ''Henry'' (2011 film), a Canadian short film * ''Henry'' (2015 film), a virtual reality film * '' Henry: Portrait of a Serial Killer'', a 1986 American crime film * ''Henry'' (comics), an American comic strip created in 1932 by Carl Anderson * "Henry", a song by New Riders of the Purple Sage Places Antarctica * Henry Bay, Wilkes Land Australia *Henry River (New South Wales) *Henry River (Western Australia) Canada * Henry Lake (Vancouver Island), British Columbia * Henry Lake (Halifax County), Nova Scotia * Henry Lake (District of Chester), Nova Scotia New Zealand * Lake Henry (New Zealand) * Henry River (New Zealand) United States * Henry, Illinois * Henry, Indiana * Henry, Nebraska * Henry, South Dakota * Henry County (disambigu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Language
Spanish () or Castilian () is a Romance languages, Romance language of the Indo-European languages, Indo-European language family that evolved from the Vulgar Latin spoken on the Iberian Peninsula of Europe. Today, it is a world language, global language with 483 million native speakers, mainly in the Americas and Spain, and about 558 million speakers total, including second-language speakers. Spanish is the official language of List of countries where Spanish is an official language, 20 countries, as well as one of the Official languages of the United Nations, six official languages of the United Nations. Spanish is the world's list of languages by number of native speakers, second-most spoken native language after Mandarin Chinese; the world's list of languages by total number of speakers, fourth-most spoken language overall after English language, English, Mandarin Chinese, and Hindustani language, Hindustani (Hindi-Urdu); and the world's most widely spoken Romance language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum-group
The platinum-group metals (PGMs) are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 and 6). The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum. They have similar physical and chemical properties, and tend to occur together in the same mineral deposits. However, they can be further subdivided into the ''iridium-group platinum-group elements'' (IPGEs: Os, Ir, Ru) and the ''palladium-group platinum-group elements'' (PPGEs: Rh, Pt, Pd) based on their behaviour in geological systems. The three elements above the platinum group in the periodic table (iron, nickel and cobalt) are all ferromagnetic; these, together with the lanthanide element gadolinium (at temperatures below 20 °C), are the only known transition metals that display ferromagnetism near room temperature. History Naturally occurring platinum an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aqueduct (water Supply)
An aqueduct is a watercourse constructed to carry water from a source to a distribution point far away. In modern engineering, the term ''aqueduct'' is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose. The term ''aqueduct'' also often refers specifically to aqueduct (bridge), a bridge carrying an artificial watercourse. Aqueducts were used in ancient Greece, the ancient Near East, Roman aqueduct, ancient Rome, Chapultepec aqueduct, ancient Aztec, and Inca aqueducts, ancient Inca. The simplest aqueducts are small ditches cut into the earth. Much larger channels may be used in modern aqueducts. Aqueducts sometimes run for some or all of their path through tunnels constructed underground. Modern aqueducts may also use pipelines. Historically, agricultural societies have constructed aqueducts to irrigate crops and supply large cities with drinking water. Etymology The word ''aqueduct'' is derived from the Latin words (''water'') a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Las Médulas
Las Médulas () is a historic gold-mining site near the town of Ponferrada in the comarca of El Bierzo (León (province), province of León, Castile and León, Spain). It was the most important gold gold mining, mine, as well as the largest open-pit mining, open-pit gold mine, in the entire Roman Empire. Las Médulas Cultural Landscape is listed by UNESCO as a World Heritage Site. Advanced aerial surveys conducted in 2014 using LIDAR have confirmed the wide extent of the Roman-era works. The spectacular landscape of Las Médulas resulted from the (wrecking of the mountains), a Roman mining technique described by Pliny the Elder in 77 AD. The technique employed was a type of hydraulic mining which involved undermining a mountain with large quantities of water. The water was supplied by interbasin transfer. At least seven long Roman aqueducts, aqueducts tapped the streams of the Cabreira, La Cabrera district (where the rainfall in the mountains is relatively high) at a range of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Augustus
Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in AD 14. The reign of Augustus initiated an Roman imperial cult, imperial cult and an era of regional hegemony, imperial peace (the or ) in which the Roman world was largely free of armed conflict. The Principate system of government was established during his reign and lasted until the Crisis of the Third Century. Octavian was born into an equites, equestrian branch of the plebeian Octavia gens, Octavia. Following his maternal great-uncle Julius Caesar's assassination of Julius Caesar, assassination in 44 BC, Octavian was named in Caesar's will as his Adoption in ancient Rome, adopted son and heir, and inherited Caesar's name, estate, and the loyalty of his legions. He, Mark Antony, and Marcus Lepidus formed the Second Triumvirat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spain
Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Europe and the fourth-most populous European Union member state. Spanning across the majority of the Iberian Peninsula, its territory also includes the Canary Islands, in the Eastern Atlantic Ocean, the Balearic Islands, in the Western Mediterranean Sea, and the Autonomous communities of Spain#Autonomous cities, autonomous cities of Ceuta and Melilla, in mainland Africa. Peninsular Spain is bordered to the north by France, Andorra, and the Bay of Biscay; to the east and south by the Mediterranean Sea and Gibraltar; and to the west by Portugal and the Atlantic Ocean. Spain's capital and List of largest cities in Spain, largest city is Madrid, and other major List of metropolitan areas in Spain, urban areas include Barcelona, Valencia, Seville, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hushing
Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to discover the ore veins. A flood of water is very effective in moving soil as well as working the ore deposits when combined with other methods such as fire-setting. Hushing was used during the formation and expansion of the Roman Empire from the 1st century BC on to the end of the empire. It was also widely used later, and apparently survived until modern times where the cost of explosives was prohibitive. It was widely used in the United States, where it was known as "booming". A variant known as hydraulic mining where jets or streams of water are used to break down deposits, especially of alluvial gold and alluvial tin, is commonly used. History The method is well described by Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portuguese Language
Portuguese ( or ) is a Western Romance language of the Indo-European language family originating from the Iberian Peninsula of Europe. It is the official language of Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique, Portugal and São Tomé and Príncipe, and has co-official language status in East Timor, Equatorial Guinea and Macau. Portuguese-speaking people or nations are known as Lusophone (). As the result of expansion during colonial times, a cultural presence of Portuguese speakers is also found around the world. Portuguese is part of the Iberian Romance languages, Ibero-Romance group that evolved from several dialects of Vulgar Latin in the medieval Kingdom of Galicia and the County of Portugal, and has kept some Gallaecian language, Celtic phonology. With approximately 250 million native speakers and 17 million second language speakers, Portuguese has approximately 267 million total speakers. It is usually listed as the List of languages by number of native speaker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Language In The Americas
The different dialects of the Spanish language spoken in the Americas are distinct from each other, as well as from those varieties spoken in the Iberian Peninsula and the Spanish Mediterranean islands—collectively known as Peninsular Spanish—and Spanish spoken elsewhere, such as in Equatorial Guinea, Western Sahara, or in the Philippines. There is great diversity among the various Hispanic American vernaculars, as there are no common traits shared by all of them which are not also in existence in one or more of the variants of Iberian Spanish. A general Hispanic American "standard" does, however, vary from the Castilian "standard" register used in television, music and, notably, in the dubbing industry. Of the more than 498 million people who speak Spanish as their native language, more than 455 million are in Latin America, the United States and Canada, as of 2022. The total amount of native and non-native speakers of Spanish as of October 2022 well-exceeds 595 million. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
