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Epithermal Vein Deposit
The epithermal vein deposit (EVP) is a type of Ore, mineral deposit that forms in the shallow subsurface, typically at depths of less than 1,500 meters below the Earth's surface. These deposits are formed by hot, Hydrothermal circulation, mineral-rich fluids that circulate through Fracture (geology), fractures and Crack (geology), cracks in rocks. As the fluids cool, they deposit minerals, such as gold, silver, copper, lead, and zinc, into the Vein (geology), veins. EVP are typically small in size, but they can be very high-grade, meaning that they contain a high concentration of valuable minerals. This makes them attractive targets for mining, despite the challenges of their small size and depth. Types of deposits High sulfidation deposit ''High-sulfide epithermal'' (HSE) deposits, or also known, ''high sulfidation deposit'', are notable for their high concentrations of sulfide minerals such as pyrite, galena, and sphalerite. Low sulfidation deposit ''Low-sulfide epitherm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Circulation
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press. and θέρμη, ''heat'' ). Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's Crust (geology), crust. In general, this occurs near volcanic activity, but can occur in the shallow to mid crust along deeply penetrating fault irregularities or in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. Hydrothermal circulation often results in Hydrothermal mineral deposit, hydrothermal mineral deposits. Seafloor hydrothermal circulation Hydrothermal circulation in the ocean, oceans is the passage of the water through mid-oceanic ridge systems. The term includes both the circulation of the well- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada
Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, the 32nd-most populous, and the ninth-least densely populated U.S. state. Nearly three-quarters of Nevada's population live in Clark County, which contains the Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City. Las Vegas is the largest city in the state. Nevada is officially known as the "Silver State" because of the importance of silver to its history and economy. It is also known as the "Battle Born State" because it achieved statehood during the Civil War (the words "Battle Born" also appear on its state flag); due to the presidency of Abraham Lincoln, the Union benefited immensely from the support of newly awarded statehood by the infusion of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baguio
Baguio ( , , ), officially the City of Baguio (; ; ), is a Cities of the Philippines#Legal classification, highly urbanized city in the Cordillera Administrative Region, Philippines. It is known as the "Summer Capital of the Philippines", owing to its cool climate since the city is located approximately above mean sea level, often cited as in the Luzon tropical pine forests ecoregion, which also makes it conducive for the growth of mossy plants, orchids and pine trees, to which it attributes its other moniker as the "City of Pines". Baguio was established as a hill station by the United States in 1900 at the site of an Ibaloi people, Ibaloi village known as ''Kafagway''. It was the United States' only hill station in Asia. Baguio is classified as a Cities of the Philippines#Classification, highly urbanized city (HUC). It is the largest city in Benguet, serving as the provincial capital from 1901 to 1916, but has since been administered independently from the province fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundary, maritime boundaries with the Pacific Ocean to the west, the Caribbean Sea to the southeast, and the Gulf of Mexico to the east. Mexico covers 1,972,550 km2 (761,610 sq mi), and is the List of countries by area, thirteenth-largest country in the world by land area. With a population exceeding 130 million, Mexico is the List of countries by population, tenth-most populous country in the world and is home to the Hispanophone#Countries, largest number of native Spanish speakers. Mexico City is the capital and List of cities in Mexico, largest city, which ranks among the List of cities by population, most populous metropolitan areas in the world. Human presence in Mexico dates back to at least 8,000 BC. Mesoamerica, considered a cradle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanajuato
Guanajuato, officially the Free and Sovereign State of Guanajuato, is one of the 32 states that make up the Political divisions of Mexico, Federal Entities of Mexico. It is divided into Municipalities of Guanajuato, 46 municipalities and its capital city is Guanajuato, Guanajuato, Guanajuato. It is located in central Mexico and is bordered by the states of Jalisco to the west, Zacatecas to the northwest, San Luis Potosí to the north, Querétaro to the east, and Michoacán to the south. It covers an area of . The state is home to several historically important cities, especially those along the "Bicentennial Route", which retraces the path of Miguel Hidalgo y Costilla's insurgent army at the beginning of the Mexican War of Independence. This route begins at Dolores Hidalgo, and passes through the Sanctuary of Atotonilco, San Miguel de Allende, Celaya, and the capital of Guanajuato City, Guanajuato. Other important cities in the state include León, Guanajuato, León, the state' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martha Mine
The Martha Mine is a gold mine in the New Zealand town of Waihi. Since July 2015 it has been owned by OceanaGold. History William Nicholl marked out a claim, calling it "Martha" after a family member. Several smaller claims were later merged to form the Martha Company. By 1882 the first battery to break gold-bearing rock was in operation. The Martha Mine eventually grew into one of the world's most important gold and silver mines, after industrial cyanide processes made recovering gold from the low-grade ores easier. Waihi prospered with the mine, by 1908 being the fastest-growing town in the Auckland Province, three times the size of Hamilton.Waihi and Gold (from the 'History & Heritage' section of the 'Waihi.org' website) In 1935 New Zealand gold output peaked during the depression, with two-thirds by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of island countries, sixth-largest island country by area and lies east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The Geography of New Zealand, country's varied topography and sharp mountain peaks, including the Southern Alps (), owe much to tectonic uplift and volcanic eruptions. Capital of New Zealand, New Zealand's capital city is Wellington, and its most populous city is Auckland. The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and subsequently developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waihi
Waihi is a town in Hauraki District in the North Island of New Zealand, especially notable for its history as a gold mine town. The town is at the foot of the Coromandel Peninsula, close to the western end of the Bay of Plenty. The nearby resort town of Waihi Beach, ten kilometres to the east, is often regarded as the westernmost point of the Bay of Plenty region. To the west are the hills of the Kaimai Ranges. Road access from this direction is through the winding Karangahake Gorge road. Waihi has a warm and temperate climate but unusually high rainfall for New Zealand's east coast with an average annual rainfall of 2147 mm. Demographics Stats NZ describes Waihī as a small urban area. It covers and had an estimated population of as of with a population density of people per km2. Waihī had a population of 5,682 in the 2023 New Zealand census, an increase of 273 people (5.0%) since the 2018 New Zealand census, 2018 census, and an increase of 1,011 people (21.6%) si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Rock
Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks. For these reasons, in geology, volcanics and shallow hypabyssal rocks are not always treated as distinct. In the context of Precambrian shield geology, the term "volcanic" is often applied to what are strictly metavolcanic rocks. Volcanic rocks and sediment that form from magma erupted into the air are called "pyroclastics," and these are also technically sedimentary rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate boundaries and in flood basalt provinces. It has been estimated that volcanic rocks cover about 8% of the Earth's current land surface. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comstock Lode
The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada (then western Utah Territory), which was the first major discovery of silver ore in the United States and named after American miner Henry Comstock. After the discovery was made public in 1859, it sparked a silver rush of prospectors to the area, scrambling to stake their claims. The discovery caused considerable excitement in California and throughout the United States, the greatest since the California Gold Rush in 1849. Mining camps soon thrived in the vicinity, which became bustling commercial centers, including Virginia City and Gold Hill. The Comstock Lode is notable not just for the immense fortunes it generated and the large role those fortunes had in the growth of Nevada and San Francisco, but also for the advances in mining technology that it spurred, such as square set timbering and the Washoe process for ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture (geology)
A fracture is any separation in a geologic formation, such as a Joint (geology), ''joint'' or a Fault (geology), ''fault'' that divides the Rock (geology), rock into two or more pieces. A fracture will sometimes form a deep fissure or crevice in the rock. Fractures are commonly caused by Stress (physics), stress exceeding the rock strength, causing the rock to lose cohesion along its weakest plane. Fractures can provide Permeability (fluid), permeability for fluid movement, such as water or hydrocarbons. Highly fractured rocks can make good aquifers or Oil reservoir, hydrocarbon reservoirs, since they may possess both significant Permeability (fluid), permeability and fracture porosity. Brittle deformation Fractures are forms of brittle deformation. There are two types of primary brittle deformation processes. Tensile fracturing results in ''joints''. ''Shear fractures'' are the first initial breaks resulting from shear forces exceeding the cohesive strength in that plane. Aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
