Related Research Articles
Kimberlite, an igneous rock and a rare variant of peridotite, is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat diamond called the Star of South Africa in 1869 spawned a diamond rush and led to the excavation of the open-pit mine called the Big Hole. Previously, the term kimberlite has been applied to olivine lamproites as Kimberlite II, however this has been in error.
In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish word placer, meaning "alluvial sand". Placer mining is an important source of gold, and was the main technique used in the early years of many gold rushes, including the California Gold Rush. Types of placer deposits include alluvium, eluvium, beach placers, aeolian placers and paleo-placers.
Volcanic pipes or volcanic conduits are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of diatreme. Volcanic pipes are composed of a deep, narrow cone of solidified magma, and are usually largely composed of one of two characteristic rock types — kimberlite or lamproite. These rocks reflect the composition of the volcanoes' deep magma sources, where the Earth is rich in magnesium. They are well known as the primary source of diamonds, and are mined for this purpose. Volcanic pipes are relatively rare by this definition based on minerals and depth of the magma source, but on the other hand volcanic diatremes are common, indeed the second commonest form of volcanic extrusion.
Canadian diamonds are diamonds which have been mined in any one of the provinces and territories of Canada. Diamond-rich areas were not commercially extracted in Canada until the early 1990s. For the first 60 years of the 20th century, diamonds originated from kimberlite pipes and alluvial deposits in places such as Africa and some from South America. Later, diamond discoveries were made in the Soviet Union. Since the 1990s, major diamond discoveries were made and mining operations began. Canadian diamonds play a large role in the world market of diamonds.
The mining of minerals in Nigeria accounts for only 0.3% of its gross domestic product, due to the influence of its vast oil resources. The domestic mining industry is underdeveloped, leading to Nigeria having to import minerals that it could produce domestically, such as salt or iron ore. The rights to ownership of mineral resources is held by the Federal Government of Nigeria, which grants titles to organizations to explore, mine, and sell mineral resources. Organized mining began in 1903, when the Mineral Survey of the Northern Protectorates was created by the British colonial government. A year later, the Mineral Survey of the Southern Protectorates was founded. By the 1940s, Nigeria was a major producer of tin, columbite, and coal. The discovery of oil in 1956 hurt the mineral extraction industries, as government and industry both began to focus on this new resource. The Nigerian Civil War in the late 1960s led many expatriate mining experts to leave the country. Mining regulation is handled by the Ministry of Solid Minerals Development, who are tasked with the responsibility of overseeing the management of all mineral resources in Nigeria. Mining law is codified in the Federal Minerals and Mining Act of 1999. Historically, Nigeria's mining industry was monopolized by state-owned public corporations. This led to a decline in productivity in almost all mineral industries. The Obasanjo administration began a process of selling off government-owned corporations to private investors in 1999. The Nigerian Mining Industry has picked up since the "Economic Diversification Agenda", from Oil & Gas, to Agriculture, Mining, etc., began in the country.
Gem Diamonds is a British-based global diamond mining business. It is headquartered in London and is listed on the London Stock Exchange. In 2017, the company generated a profit of $20.8 million.
The following outline is provided as an overview of and topical guide to mining:
The Central African Republic's mineral resource endowment includes copper, diamond, gold, graphite, ilmenite, iron ore, kaolin, kyanite, lignite, limestone, manganese, monazite, quartz, rutile, salt, tin, and uranium. Of these commodities, only diamond and gold were produced in 2006 - subsistence farming was the mainstay of the economy.
Mining in the United Kingdom produces a wide variety of fossil fuels, metals, and industrial minerals due to its complex geology. In 2013, there were over 2,000 active mines, quarries, and offshore drilling sites on the continental land mass of the United Kingdom producing £34bn of minerals and employing 36,000 people.
Artisanal and small-scale mining (ASM) is a blanket term for a type of subsistence mining involving a miner who may or may not be officially employed by a mining company but works independently, mining minerals using their own resources, usually by hand.
The geology of Burkina Faso is dominated by Precambrian rocks of the Guinea Rise, a dome of Archaean rocks, composed largely of migmatites, gneisses and amphibolites, over which lie the greenstone belts of the early Proterozoic age. The latter are metasediments and metavolcanics assigned largely to the Birimian Supergroup, a suite of rocks in which can also economically significant mineralization occurs. Pre-Birimian migmatites, gneisses, and amphibolites, located under the Birimian rocks, are the oldest rocks in the country. The Birimian deposits in the southwestern part of the country are typically divided between clastic and volcano-clastic formations.
The Dalnyaya diamond mine is a prominent diamond mining operation located in the Sakha Republic (Yakutia) of Russia, within the Yakutian Diamond Province. Situated amidst the rich diamond deposits of the region, the Dalnyaya mine plays a significant role in Russia's diamond industry and contributes to the country's status as one of the world's leading diamond producers.
Tanzania is a land rich in minerals. Mining makes up more than 50% of the country's total exports, of which a large part comes from gold. The country has gold reserves of 10 million ounces, generating revenue of over a billion USD. Diamonds are also found in significant amounts. Since it was opened in 1940, the Williamson diamond mine has produced 19 million carats (3,800 kg) of diamonds. Gemstones, nickel, copper, uranium, kaolin, titanium, cobalt and platinum are also mined in Tanzania. Illegal mining and corruption are ongoing problems. In 2017, the government passed a series of bills aimed at increasing revenue from minerals after a scandal which caused the dismissal of the Minister for Energy and Minerals.
The mining industry of Liberia has witnessed a revival after the civil war which ended in 2003. Gold, diamonds, and iron ore form the core minerals of the mining sector with a new Mineral Development Policy and Mining Code being put in place to attract foreign investments. In 2013, the mineral sector accounted for 11% of GDP in the country and the World Bank projected a further increase in the sector by 2017.
The mining industry of Malawi, includes a number of gemstones and other minerals.
The mining industry of Mali is dominated by gold extraction but also produces diamonds, rocksalt, phosphates, semi precious stones, bauxite, iron ore, and manganese. The importance of mining and production of raw minerals has changed throughout time and has involved many foreign stakeholders, most notably France, the former Soviet Union, and South Africa. Gold, followed by cotton, is the top export item, making it a large contributor to the country’s economy. Mineral extraction in the country is done both via industrial mining and artisanal mining, and both methods of production have had profound impacts on the economy, sociocultural landscape, and environment.
The mining industry of Senegal is mainly centred on the production of phosphates and industrial limestone. Senegal is one of the leading producers of phosphates in the world, accounting for about 6% of exports in 2006, and deposits are of a particularly high quality. In the coastal region of the country, titanium-bearing minerals have been found and the reserve is estimated at 10 million tons. The mineral sector's exports accounts for 20% of total exports of the country and constitutes 20% of the GDP.
The geology of Liberia is largely extremely ancient rock formed between 3.5 billion and 539 million years ago in the Archean and the Neoproterozoic, with some rocks from the past 145 million years near the coast. The country has rich iron resources as well as some diamonds, gold and other minerals in ancient sediment formations weathered to higher concentrations by tropical rainfall.
The geology of Lesotho is built on ancient crystalline basement rock up to 3.6 billion years old, belonging to the Kaapvaal Craton, a section of stable primordial crust. Most of the rocks in the country are sedimentary or volcanic units, belonging to the Karoo Supergroup. The country is notable for large fossil deposits and intense erosion due to high rainfall and a rare case of southern African glaciation during the last ice age. Lesotho has extensive diamonds and other natural resources and has the highest concentration of kimberlite pipes anywhere in the world.
The geology of Namibia encompasses rocks of Paleoproterozoic, Mesoproterozoic and Neoproterozoic and Paleozoic to Cenozoic age. About 46% of the countryʼs surface are bedrock exposure, while the remainder is covered by the young overburden sediments of the Kalahari and Namib deserts.
References
- 1 2 3 4 "2011 Minerals Yearbook" (PDF). U.S. Department of the Interior:U.S. Geological Survey. Retrieved 26 May 2015.
- 1 2 3 Survey 2011, p. 20.
- 1 2 3 4 https://www.centralbank.org.ls/images/Publications/Research/Reports/MonthlyEconomicReviews/2012/July%202012%20ER%20-%20final.pdf.
{{cite web}}: Missing or empty|title=(help)