Phú Lương is a rural district of Thái Nguyên province in the Northeast region of Vietnam . As of 2003, the district had a population of 106,834. The district covers an area of 369 km. The district capital lies at Đu .
99-446: Đu , Giang Tiên , Cổ Lũng, Động Đạt, Hợp Thành, Ôn Lương, Phấn Mễ, Phú Đô, Phủ Lý, Sơn Cẩm, Tức Tranh, Vô Tranh, Yên Đổ, Yên Lạc, Yên Ninh, Yên Trạch 21°40′01″N 105°45′00″E / 21.667°N 105.750°E / 21.667; 105.750 This article about a location in Thái Nguyên Province , Vietnam is a stub . You can help Misplaced Pages by expanding it . Th%C3%A1i Nguy%C3%AAn Province Thái Nguyên
198-452: A combination of these processes. Other mechanisms, such as melting from a meteorite impact , are less important today, but impacts during the accretion of the Earth led to extensive melting, and the outer several hundred kilometers of the early Earth was probably a magma ocean . Impacts of large meteorites in the last few hundred million years have been proposed as one mechanism responsible for
297-420: A depth of 2,488 m (8,163 ft). The temperature of this magma was estimated at 1,050 °C (1,920 °F). Temperatures of deeper magmas must be inferred from theoretical computations and the geothermal gradient. Most magmas contain some solid crystals suspended in the liquid phase. This indicates that the temperature of the magma lies between the solidus , which is defined as the temperature at which
396-427: A dissolved water content in excess of 10%. Water is somewhat less soluble in low-silica magma than high-silica magma, so that at 1,100 °C and 0.5 GPa , a basaltic magma can dissolve 8% H 2 O while a granite pegmatite magma can dissolve 11% H 2 O . However, magmas are not necessarily saturated under typical conditions. Carbon dioxide is much less soluble in magmas than water, and frequently separates into
495-406: A distinct fluid phase even at great depth. This explains the presence of carbon dioxide fluid inclusions in crystals formed in magmas at great depth. Viscosity is a key melt property in understanding the behaviour of magmas. Whereas temperatures in common silicate lavas range from about 800 °C (1,470 °F) for felsic lavas to 1,200 °C (2,190 °F) for mafic lavas, the viscosity of
594-435: A high charge (the high-field-strength elements, or HSFEs), which include such elements as zirconium , niobium , hafnium , tantalum , the rare-earth elements , and the actinides . Potassium can become so enriched in melt produced by a very low degree of partial melting that, when the magma subsequently cools and solidifies, it forms unusual potassic rock such as lamprophyre , lamproite , or kimberlite . When enough rock
693-546: A hypothetical magma formed entirely from melted silica, NBO/T would be 0, while in a hypothetical magma so low in network formers that no polymerization takes place, NBO/T would be 4. Neither extreme is common in nature, but basalt magmas typically have NBO/T between 0.6 and 0.9, andesitic magmas have NBO/T of 0.3 to 0.5, and rhyolitic magmas have NBO/T of 0.02 to 0.2. Water acts as a network modifier, and dissolved water drastically reduces melt viscosity. Carbon dioxide neutralizes network modifiers, so dissolved carbon dioxide increases
792-474: A layer that appears to contain silicate melt and that stretches for at least 1,000 kilometers within the middle crust along the southern margin of the Tibetan Plateau. Granite and rhyolite are types of igneous rock commonly interpreted as products of the melting of continental crust because of increases in temperature. Temperature increases also may contribute to the melting of lithosphere dragged down in
891-420: A magma. In practice, it is difficult to unambiguously identify primary magmas, though it has been suggested that boninite is a variety of andesite crystallized from a primary magma. The Great Dyke of Zimbabwe has also been interpreted as rock crystallized from a primary magma. The interpretation of leucosomes of migmatites as primary magmas is contradicted by zircon data, which suggests leucosomes are
990-564: A one lump sum payment. Consequently, these efforts led to the collection of US$ 65 million to develop industrial parks. The Diem Thuy Industrial Park is one such example and features 77 projects with combined investment exceeding US$ 1.1 billion. This park's projects are modern, eco-friendly, and employ over 20,000 locals. Núi Cốc reservoir is 25 km west of Thái Nguyên city. It covers an area of 2,500 hectares (6,200 acres) with 23 metres (75 ft) deep waters that can store 175 million cubic metres. The lake waters feeds an irrigation canal and
1089-425: A rock type commonly enriched in incompatible elements. Bowen's reaction series is important for understanding the idealised sequence of fractional crystallisation of a magma. Magma composition can be determined by processes other than partial melting and fractional crystallization. For instance, magmas commonly interact with rocks they intrude, both by melting those rocks and by reacting with them. Assimilation near
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#17328724260111188-492: A second plant in Thai Nguyen. This funding should raise its regional production per month from 20 million to 35 million units. For enhancing its overall competitiveness, Thai Nguyen is actively encouraging the private and high-tech sectors to develop production clusters and connect value chains. Thai Nguyen's six industrial parks are spread over 1400 hectares of land area, five of which have already received funding. The province
1287-458: A small hydroelectric power station with three units of 630 KW capacity each, for a total output of about 2 GWh. The irrigation system was built in 1977. However, the power plant construction on the irrigation canal was started in Jan 2008 and the plant commissioned in Jan 2010. A 22 kV transmission line carries the power to a nearby grid. Two railway lines serve Thái Nguyên Province, and particularly
1386-567: A solidified crust. Most basalt lavas are of ʻAʻā or pāhoehoe types, rather than block lavas. Underwater, they can form pillow lavas , which are rather similar to entrail-type pahoehoe lavas on land. Ultramafic magmas, such as picritic basalt, komatiite , and highly magnesian magmas that form boninite , take the composition and temperatures to the extreme. All have a silica content under 45%. Komatiites contain over 18% magnesium oxide, and are thought to have erupted at temperatures of 1,600 °C (2,910 °F). At this temperature there
1485-407: A subduction zone. When rocks melt, they do so over a range of temperature, because most rocks are made of several minerals , which all have different melting points. The temperature at which the first melt appears (the solidus) is lower than the melting temperature of any one of the pure minerals. This is similar to the lowering of the melting point of ice when it is mixed with salt. The first melt
1584-440: A ten-fold increase to over US$ 23 billion in the 2013 – 2017 period. The province hosted nearly 7,200 businesses in 2020 with a combined capital value approaching US$ 5.4 billion. As per Thai Nguyen's Department of Industry and Trade, for the first three quarters of 2020, the province's total industrial gross output exceeded US$ 27 billion, while the domestic economic sector achieved US$ 1.8 billion. Both of these were over 70 percent of
1683-439: A tetrahedral arrangement around the much smaller silicon ion. This is called a silica tetrahedron . In a magma that is low in silicon, these silica tetrahedra are isolated, but as the silicon content increases, silica tetrahedra begin to partially polymerize, forming chains, sheets, and clumps of silica tetrahedra linked by bridging oxygen ions. These greatly increase the viscosity of the magma. The tendency towards polymerization
1782-638: A typical viscosity of 3.5 × 10 cP (3,500 Pa⋅s) at 1,200 °C (2,190 °F). This is slightly greater than the viscosity of smooth peanut butter . Intermediate magmas show a greater tendency to form phenocrysts . Higher iron and magnesium tends to manifest as a darker groundmass , including amphibole or pyroxene phenocrysts. Mafic or basaltic magmas have a silica content of 52% to 45%. They are typified by their high ferromagnesian content, and generally erupt at temperatures of 1,100 to 1,200 °C (2,010 to 2,190 °F). Viscosities can be relatively low, around 10 to 10 cP (10 to 100 Pa⋅s), although this
1881-633: A viscosity of about 1 cP (0.001 Pa⋅s). Because of this very high viscosity, felsic lavas usually erupt explosively to produce pyroclastic (fragmental) deposits. However, rhyolite lavas occasionally erupt effusively to form lava spines , lava domes or "coulees" (which are thick, short lava flows). The lavas typically fragment as they extrude, producing block lava flows . These often contain obsidian . Felsic lavas can erupt at temperatures as low as 800 °C (1,470 °F). Unusually hot (>950 °C; >1,740 °F) rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in
1980-474: Is Bánh chưng from Bờ Đậu village about 10 km north of Thái Nguyên City in Phú Lương District , where both sides of the road are lined with shops selling the local specialty made from glutinous rice cake, mung bean puree, and pork wrapped in aromatic leaves (usually Stachyphrynium placentarium , sometimes banana ) and tied up with string made from a kind of bamboo, which can be used to slice
2079-531: Is 120 to 200 metres high and more with a sloping gradient of 5° to 20° and is an ideal place for planting industrial crops and perennial fruit trees. Field land accounts 12.4%, a part of which is scattered along streams and can be easily exposed to severe meteorological conditions (such as sudden floods and droughts) and is difficult to harvest. Of the total land area, 2,207.89 km (65.22% of natural area) are used and 1,096.69 km (30.78% of natural area) are unused. Of unused land area, only 17.14 km area
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#17328724260112178-544: Is 50 km from Noi Bai international airport, 200 km from the Chinese border, 75 km from the center of Hanoi and 200 km from Hai Phong. The exchange is carried out via road, rail and waterways in the province Main water features include the Công River and Núi Cốc Lake . Thái Nguyên has many mountain ranges running from south to north. Their structure is made of strongly decayed rocks with many caves and valleys. In
2277-571: Is a province in the Northeast region of Vietnam . It is a mountainous, midland province with a land area of 3,521.96 km (1,359.84 sq mi) and a population of 1,350,345 as of 2023, with 445,505 people in urban areas and 904,849 people in rural areas. Its multi-ethnic society is composed of eight ethnic groups. With its rich mineral resources and salubrious climate, the province offers significant opportunities for industrial development for both domestic and foreign investors. Thái Nguyên
2376-409: Is added to the rock, the temperature remains at 1274 °C until either the anorthite or diopside is fully melted. The temperature then rises as the remaining mineral continues to melt, which shifts the melt composition away from the eutectic. For example, if the content of anorthite is greater than 43%, the entire supply of diopside will melt at 1274 °C., along with enough of the anorthite to keep
2475-418: Is also known as an educational centre and ranks 3rd nationwide, having 21 universities and colleges. The province is also the centre of tea industry in the country with an area of 16,000 ha. (second only to Lâm Đồng ) with a production of 100,000 tonnes (98,000 long tons; 110,000 short tons) per year. Its dried tea production is 25,000 tonnes (25,000 long tons; 28,000 short tons) per year. The tea produced here
2574-444: Is called the eutectic and has a composition that depends on the combination of minerals present. For example, a mixture of anorthite and diopside , which are two of the predominant minerals in basalt , begins to melt at about 1274 °C. This is well below the melting temperatures of 1392 °C for pure diopside and 1553 °C for pure anorthite. The resulting melt is composed of about 43 wt% anorthite. As additional heat
2673-410: Is concentrated in a thin layer in the toothpaste next to the tube, and only here does the toothpaste behave as a fluid. Thixotropic behavior also hinders crystals from settling out of the magma. Once the crystal content reaches about 60%, the magma ceases to behave like a fluid and begins to behave like a solid. Such a mixture of crystals with melted rock is sometimes described as crystal mush . Magma
2772-589: Is considered to have the finest quality throughout Vietnam. The province's name derives from the Sino-Vietnamese 太原 . According to the General Statistics Office of the Government of Vietnam, the population of Thái Nguyên province as of 2019 was 1,286,751 with a density of 364 people per km over a total land area of 3,526.64 km (1,361.64 sq mi). The male population during this period
2871-402: Is cultivable; bare land and deserted hills occupy 412.5 km . A major problem faced by Thái Nguyên province is to recover deserted areas. Farming, aquaculture and industries are some of the important economic activities of the province. In 2008, as against the national figure of 7,592 cooperatives of Agriculture, Forestry and Fishery cooperatives, there are only 83 agriculture cooperatives in
2970-456: Is driven out of the oceanic lithosphere in subduction zones , and it causes melting in the overlying mantle. Hydrous magmas with the composition of basalt or andesite are produced directly and indirectly as results of dehydration during the subduction process. Such magmas, and those derived from them, build up island arcs such as those in the Pacific Ring of Fire . These magmas form rocks of
3069-504: Is expected to generate a revenue of US$ 110 million annually, employing over 10,000 workers. In the same month, China's Trina Solar received Thai Nguyen's approval to produce photovoltaic cells and solar power. With investment exceeding US$ 200 million, this facility has a planned capacity of over 250 million products a year. The plant is expected to begin operations from June 2021 and add over 1,800 jobs. In November 2020, South Korean touchscreen manufacturer Samju Vina, injected capital to add
Phú Lương district - Misplaced Pages Continue
3168-417: Is expressed as NBO/T, where NBO is the number of non-bridging oxygen ions and T is the number of network-forming ions. Silicon is the main network-forming ion, but in magmas high in sodium, aluminium also acts as a network former, and ferric iron can act as a network former when other network formers are lacking. Most other metallic ions reduce the tendency to polymerize and are described as network modifiers. In
3267-529: Is famous for its tree plantations. Its historical importance is due to the fact that Ho Chi Minh resided here in the Phu Dinh village of Dinh Hoa district when he planned Dien Bien Phu . Before he moved to Hanoi, he came here from Tan Trao and declared independence. The city is also the centre of heavy industries of northern Vietnam. Thái Nguyên Iron and Steel Company ( TISCO ), which is located in Thái Nguyên city,
3366-433: Is favourable for developing agriculture and forestry. The total land area is 3,534.45 square kilometres (1,364.66 sq mi) and can be divided into three classes. Mountainous land accounts for 48.4% area and is formed from the decaying of magma , rocks and sedimentary rock . Hilly land accounts for 31.4% area and is made of condensed sand, clay and ancient alluvia . Hill land in some places such as Đại Từ, Phú Lương
3465-466: Is magma extruded onto the surface, are almost all in the range 700 to 1,400 °C (1,300 to 2,600 °F), but very rare carbonatite magmas may be as cool as 490 °C (910 °F), and komatiite magmas may have been as hot as 1,600 °C (2,900 °F). Magma has occasionally been encountered during drilling in geothermal fields, including drilling in Hawaii that penetrated a dacitic magma body at
3564-647: Is melted before the heat supply is exhausted. Pegmatite may be produced by low degrees of partial melting of the crust. Some granite -composition magmas are eutectic (or cotectic) melts, and they may be produced by low to high degrees of partial melting of the crust, as well as by fractional crystallization . Most magmas are fully melted only for small parts of their histories. More typically, they are mixes of melt and crystals, and sometimes also of gas bubbles. Melt, crystals, and bubbles usually have different densities, and so they can separate as magmas evolve. As magma cools, minerals typically crystallize from
3663-416: Is melted, the small globules of melt (generally occurring between mineral grains) link up and soften the rock. Under pressure within the earth, as little as a fraction of a percent of partial melting may be sufficient to cause melt to be squeezed from its source. Melt rapidly separates from its source rock once the degree of partial melting exceeds 30%. However, usually much less than 30% of a magma source rock
3762-526: Is one of Vietnam's top 20 state-owned companies, and has made a sizable contribution to Vietnam's economy. The city is located on the bank of the Cầu River has a geographical area of approximately 17,707 hectares (43,750 acres) and its population was 228,064 in 2005. Samsung Electronics has their largest mobile phone factory in Thai Nguyen, employing over 60,000 people. The factory has operated since 2014 and has an area of 100 ha. Thai Nguyen's export experienced
3861-615: Is practically no polymerization of the mineral compounds, creating a highly mobile liquid. Viscosities of komatiite magmas are thought to have been as low as 100 to 1000 cP (0.1 to 1 Pa⋅s), similar to that of light motor oil. Most ultramafic lavas are no younger than the Proterozoic , with a few ultramafic magmas known from the Phanerozoic in Central America that are attributed to a hot mantle plume . No modern komatiite lavas are known, as
3960-545: Is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones , continental rift zones , mid-ocean ridges and hotspots . Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization , contamination with crustal melts, magma mixing, and degassing. Following its ascent through
4059-447: Is promoting infrastructure investment in its 105-hectare Quyet Thang Hi-Tech Industrial Park that is situated eight kilometers away from Thai Nguyen city center. The province's plans include 35 industrial clusters with an area of nearly 1,260 hectares. The province has called for investment in 11 of these clusters, which have a planned area of over 280 hectares. The province aims to attract investment in secondary industries that complement
Phú Lương district - Misplaced Pages Continue
4158-448: Is still many orders of magnitude higher than water. This viscosity is similar to that of ketchup . Basalt lavas tend to produce low-profile shield volcanoes or flood basalts , because the fluidal lava flows for long distances from the vent. The thickness of a basalt lava, particularly on a low slope, may be much greater than the thickness of the moving lava flow at any one time, because basalt lavas may "inflate" by supply of lava beneath
4257-413: Is typically also viscoelastic , meaning it flows like a liquid under low stresses, but once the applied stress exceeds a critical value, the melt cannot dissipate the stress fast enough through relaxation alone, resulting in transient fracture propagation. Once stresses are reduced below the critical threshold, the melt viscously relaxes once more and heals the fracture. Temperatures of molten lava, which
4356-408: Is typically the most abundant magmatic gas, followed by carbon dioxide and sulfur dioxide . Other principal magmatic gases include hydrogen sulfide , hydrogen chloride , and hydrogen fluoride . The solubility of magmatic gases in magma depends on pressure, magma composition, and temperature. Magma that is extruded as lava is extremely dry, but magma at depth and under great pressure can contain
4455-666: The Snake River Plain of the northwestern United States. Intermediate or andesitic magmas contain 52% to 63% silica, and are lower in aluminium and usually somewhat richer in magnesium and iron than felsic magmas. Intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes , such as in the Andes . They are also commonly hotter, in the range of 850 to 1,100 °C (1,560 to 2,010 °F)). Because of their lower silica content and higher eruptive temperatures, they tend to be much less viscous, with
4554-458: The calc-alkaline series, an important part of the continental crust . With low density and viscosity, hydrous magmas are highly buoyant and will move upwards in Earth's mantle. The addition of carbon dioxide is relatively a much less important cause of magma formation than the addition of water, but genesis of some silica-undersaturated magmas has been attributed to the dominance of carbon dioxide over water in their mantle source regions. In
4653-453: The convection of solid mantle, it will cool slightly as it expands in an adiabatic process , but the cooling is only about 0.3 °C per kilometer. Experimental studies of appropriate peridotite samples document that the solidus temperatures increase by 3 °C to 4 °C per kilometer. If the rock rises far enough, it will begin to melt. Melt droplets can coalesce into larger volumes and be intruded upwards. This process of melting from
4752-523: The 163 km (101 mi) Luu Xa–Hạ Long line was built at standard gauge , and the 75 km (47 mi) Hanoi–Quán Triều line was built at mixed gauge . The rail spur connecting Luu Xa and Kép was a strategic line constructed between October 1965 and December 1966 by a railroad engineering division of the Chinese People's Liberation Army , who operated in North Vietnam repairing railway lines at
4851-537: The 2015–2020 period. As per the Foreign Investment Agency (FIA), in August 2020, the province hosted over 172 foreign-invested projects. Together these enterprises added over US$ 8 billion in registered capital. This made Thai Nguyen among the country's top 10 localities in terms of international investment inflow. In a bid to attract investors with industrial expertise, the province is concentrating on improving
4950-472: The Earth's mantle has cooled too much to produce highly magnesian magmas. Some silicic magmas have an elevated content of alkali metal oxides (sodium and potassium), particularly in regions of continental rifting , areas overlying deeply subducted plates , or at intraplate hotspots . Their silica content can range from ultramafic ( nephelinites , basanites and tephrites ) to felsic ( trachytes ). They are more likely to be generated at greater depths in
5049-465: The Earth's upper crust, but this varies widely by region, from a low of 5–10 °C/km within oceanic trenches and subduction zones to 30–80 °C/km along mid-ocean ridges or near mantle plumes . The gradient becomes less steep with depth, dropping to just 0.25 to 0.3 °C/km in the mantle, where slow convection efficiently transports heat. The average geothermal gradient is not normally steep enough to bring rocks to their melting point anywhere in
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#17328724260115148-631: The Samsung group and increase its localization degree. Specifically, industries in electronics, electric, software, high precision mechanical, and textile are favored. The investment locations promoted by Thai Nguyen include the industrial zones in Yen Binh, Diem Thuy, and Song Cong. These, along with the province-wide industrial clusters, are equipped with appropriate technical infrastructure to establish enterprises. To raise funds, Thai Nguyen provincial authorities encouraged investors to lease land for 50 years for
5247-476: The anorthite is melted. If the anorthite content of the mixture is less than 43%, then all the anorthite will melt at the eutectic temperature, along with part of the diopside, and the remaining diopside will then gradually melt as the temperature continues to rise. Because of eutectic melting, the composition of the melt can be quite different from the source rock. For example, a mixture of 10% anorthite with diopside could experience about 23% partial melting before
5346-582: The city of Thái Nguyên . The first line connects Hanoi Railway Station to Quán Triều Railway Station (Quán Triều Ward), and the second connects Lưu Xá Railway Station (Phú Xá Ward) to Hạ Long Railway Station , Hạ Long , via a railway junction at Kép in Bắc Giang province . Both lines were built after the First Indochina War ; unlike most railway lines in Vietnam, which were established in metre gauge ,
5445-481: The country. There are over 20 peaks with the park area, others of note include Thien Thi at 1,375 m, Thach Ban at 1,388 m and Phu Nghia at 1,300 m. Sharp peaks with sloping sides and numerous, deep partitions are characteristic of the topology. The boundary of the national park is located at an altitude of 100 m around the Tam Đảo range. There is a larger buffer zone (which has area of approximately 535 km ) which surrounds
5544-458: The crust or upper mantle, so magma is produced only where the geothermal gradient is unusually steep or the melting point of the rock is unusually low. However, the ascent of magma towards the surface in such settings is the most important process for transporting heat through the crust of the Earth. Rocks may melt in response to a decrease in pressure, to a change in composition (such as an addition of water), to an increase in temperature, or to
5643-603: The crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion , such as a dike , a sill , a laccolith , a pluton , or a batholith . While the study of magma has relied on observing magma after its transition into a lava flow , magma has been encountered in situ three times during geothermal drilling projects , twice in Iceland (see Use in energy production ) and once in Hawaii. Magma consists of liquid rock that usually contains suspended solid crystals. As magma approaches
5742-455: The crystallization process would not change the overall composition of the melt plus solid minerals. This situation is described as equillibrium crystallization . However, in a series of experiments culminating in his 1915 paper, Crystallization-differentiation in silicate liquids , Norman L. Bowen demonstrated that crystals of olivine and diopside that crystallized out of a cooling melt of forsterite , diopside, and silica would sink through
5841-399: The eutectic temperature of 1274 °C. This shifts the remaining melt towards its eutectic composition of 43% diopside. The eutectic is reached at 1274 °C, the temperature at which diopside and anorthite begin crystallizing together. If the melt was 90% diopside, the diopside would begin crystallizing first until the eutectic was reached. If the crystals remained suspended in the melt,
5940-559: The extensive basalt magmatism of several large igneous provinces. Decompression melting occurs because of a decrease in pressure. It is the most important mechanism for producing magma from the upper mantle. The solidus temperatures of most rocks (the temperatures below which they are completely solid) increase with increasing pressure in the absence of water. Peridotite at depth in the Earth's mantle may be hotter than its solidus temperature at some shallower level. If such rock rises during
6039-460: The first three quarters of 2020, industry and construction covered nearly 60 percent of the province's economy while the services sector accounted for roughly one-third of the economy. In the same period, the province's GDP per capita reached US$ 4,260, while industrial production rose by over 16 percent, and local exports grew by over 13 percent. Thai Nguyen has also experienced significant development in infrastructure and labor productivity. Recently,
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#17328724260116138-468: The highlands and mountainous regions is low, while that of urban areas is very high. Vo Nhai District has lowest population density with 72 inhabitants/km and Thái Nguyên city has the highest with 1,260 inhabitants/km . Thái Nguyên borders six provinces: Bắc Kạn , Vĩnh Phúc , Tuyên Quang , Lạng Sơn , Bắc Giang , Hanoi . Thái Nguyên is the gateway for socio-economic exchange with the Red River delta. It
6237-594: The hottest and the coldest months are 28.9 °C in June and 15.2 °C in January. The lowest recorded is 13.7 °C. Total number of sunny hours in a year is ranges between 1,300 and 1,750, which is equally distributed for months in a year. The climate is divided into 4 distinct seasons: Spring - Summer - Autumn - Winter. The average rainfall per annum lies in the range of 2,000 to 2,500 mm; it rains most in August and least in January. Generally speaking, Thái Nguyên's climate
6336-420: The importance of each mechanism being a topic of continuing research. The change of rock composition most responsible for the creation of magma is the addition of water. Water lowers the solidus temperature of rocks at a given pressure. For example, at a depth of about 100 kilometers, peridotite begins to melt near 800 °C in the presence of excess water, but near 1,500 °C in the absence of water. Water
6435-509: The local investment climate. Thai Nguyen has prioritized timely issuance of government policies, guidance, and support for financiers. Local authorities have also shown a keen interest in high technology industries and ancillaries. In December 2020, Hong Kong's electronic firm, DBG Technology, was awarded an investment certificate by provincial authorities to set up a US$ 80 million manufacturing facility. This facility will manufacture laptops, cameras, phones, audio equipment, and home appliances. It
6534-476: The magma completely solidifies, and the liquidus , defined as the temperature at which the magma is completely liquid. Calculations of solidus temperatures at likely depths suggests that magma generated beneath areas of rifting starts at a temperature of about 1,300 to 1,500 °C (2,400 to 2,700 °F). Magma generated from mantle plumes may be as hot as 1,600 °C (2,900 °F). The temperature of magma generated in subduction zones, where water vapor lowers
6633-408: The magma. Gabbro may have a liquidus temperature near 1,200 °C, and the derivative granite-composition melt may have a liquidus temperature as low as about 700 °C. Incompatible elements are concentrated in the last residues of magma during fractional crystallization and in the first melts produced during partial melting: either process can form the magma that crystallizes to pegmatite ,
6732-419: The mantle than subalkaline magmas. Olivine nephelinite magmas are both ultramafic and highly alkaline, and are thought to have come from much deeper in the mantle of the Earth than other magmas. Tholeiitic basalt magma Rhyolite magma Some lavas of unusual composition have erupted onto the surface of the Earth. These include: The concentrations of different gases can vary considerably. Water vapor
6831-424: The melt at different temperatures. This resembles the original melting process in reverse. However, because the melt has usually separated from its original source rock and moved to a shallower depth, the reverse process of crystallization is not precisely identical. For example, if a melt was 50% each of diopside and anorthite, then anorthite would begin crystallizing from the melt at a temperature somewhat higher than
6930-438: The melt at the eutectic composition. Further heating causes the temperature to slowly rise as the remaining anorthite gradually melts and the melt becomes increasingly rich in anorthite liquid. If the mixture has only a slight excess of anorthite, this will melt before the temperature rises much above 1274 °C. If the mixture is almost all anorthite, the temperature will reach nearly the melting point of pure anorthite before all
7029-449: The melt deviated from the eutectic, which has the composition of about 43% anorthite. This effect of partial melting is reflected in the compositions of different magmas. A low degree of partial melting of the upper mantle (2% to 4%) can produce highly alkaline magmas such as melilitites , while a greater degree of partial melting (8% to 11%) can produce alkali olivine basalt. Oceanic magmas likely result from partial melting of 3% to 15% of
7128-402: The melt on geologically relevant time scales. Geologists subsequently found considerable field evidence of such fractional crystallization . When crystals separate from a magma, then the residual magma will differ in composition from the parent magma. For instance, a magma of gabbroic composition can produce a residual melt of granitic composition if early formed crystals are separated from
7227-429: The melting temperature, may be as low as 1,060 °C (1,940 °F). Magma densities depend mostly on composition, iron content being the most important parameter. Magma expands slightly at lower pressure or higher temperature. When magma approaches the surface, its dissolved gases begin to bubble out of the liquid. These bubbles had significantly reduced the density of the magma at depth and helped drive it toward
7326-481: The more abundant elements in the source rock. The ions of these elements fit rather poorly in the structure of the minerals making up the source rock, and readily leave the solid minerals to become highly concentrated in melts produced by a low degree of partial melting. Incompatible elements commonly include potassium , barium , caesium , and rubidium , which are large and weakly charged (the large-ion lithophile elements, or LILEs), as well as elements whose ions carry
7425-415: The most abundant chemical elements in the Earth's crust, with smaller quantities of aluminium , calcium , magnesium , iron , sodium , and potassium , and minor amounts of many other elements. Petrologists routinely express the composition of a silicate magma in terms of the weight or molar mass fraction of the oxides of the major elements (other than oxygen) present in the magma. Because many of
7524-565: The mountains of Thái Nguyên province provide shelter for a considerable part from monsoon winds. With terrain sloping from high mountains to the low zones and midlands, in terms temperature in winter, Thái Nguyên has three climatic sub-zones. A cold sub-zone in Võ Nhai District, a temperate subzone including Định Hóa, Phú Lương and southern Võ Nhai districts and a warm subzone which includes Đại Từ, Đồng Hỷ, Phú Bình, Phổ Yên City, Thái Nguyên City and Sông Công City. The average temperatures in
7623-525: The national park which has an altitude below 100 m. Seventy per cent of the area of the park is covered by natural and artificial forest. The natural forest is about 220 km and the human altered forest is about 30 km There are two other mountain ranges in the province, both running in a northwest–southeast direction; the Ngan Son range running from Bắc Kạn to Võ Nhai District and the Bac Son range. Many of
7722-439: The presence of carbon dioxide, experiments document that the peridotite solidus temperature decreases by about 200 °C in a narrow pressure interval at pressures corresponding to a depth of about 70 km. At greater depths, carbon dioxide can have more effect: at depths to about 200 km, the temperatures of initial melting of a carbonated peridotite composition were determined to be 450 °C to 600 °C lower than for
7821-630: The properties of a magma (such as its viscosity and temperature) are observed to correlate with silica content, silicate magmas are divided into four chemical types based on silica content: felsic , intermediate , mafic , and ultramafic . Felsic or silicic magmas have a silica content greater than 63%. They include rhyolite and dacite magmas. With such a high silica content, these magmas are extremely viscous, ranging from 10 cP (10 Pa⋅s) for hot rhyolite magma at 1,200 °C (2,190 °F) to 10 cP (10 Pa⋅s) for cool rhyolite magma at 800 °C (1,470 °F). For comparison, water has
7920-508: The province experienced an influx of sustainable ventures. In 2020, over ten investment certificates were granted to eco-friendly and energy-efficient ventures, with a combined worth of over US$ 30 million. Over the past decade, Thai Nguyen attracted a considerable amount of foreign direct investment. Samsung's establishment of a mobile phone manufacturing complex in the province has dramatically boosted Thai Nguyen's FDI. The province achieved over 13 percent compound annual growth rate (CAGR) during
8019-402: The province was 356.9 kg as against the national figure of 501.9 kg in 2007. In 2007, the industrial output of the province was a meagre 11,987.5 Bhilldongs against the national output of 1.47 million Bhilldongs. The economy of the province is largely dictated by its capital city, Thái Nguyên, which is the fastest growing city of North Vietnam. The city is the gateway to northwest Vietnam . It
8118-459: The province's annual target. In the same period, foreign-invested enterprises generated close to US$ 23 billion, an increase of 2.3 percent over the previous year. Among the province's industries, the electronics and high-tech domains delivered the best results. Their production increased by over 16 percent year-on-year for laptops, while earphone manufacturing grew by five percent. The socioeconomics of Thai Nguyen has seen remarkable development. In
8217-399: The province. There were 638 farms as against the national number of 120,699 in 2008. The output value of agriculture produce at constant 1994 prices in the province was 1667.1 billion đồngs against the national value of 156681.9 billion đồngs. The province produced 410,400 tonnes of cereals as against the national production of 43.68 million tonnes. The per capita production of cereals in
8316-411: The rate of flow is proportional to the shear stress . Instead, a typical magma is a Bingham fluid , which shows considerable resistance to flow until a stress threshold, called the yield stress, is crossed. This results in plug flow of partially crystalline magma. A familiar example of plug flow is toothpaste squeezed out of a toothpaste tube. The toothpaste comes out as a semisolid plug, because shear
8415-526: The request of Ho Chi Minh . Thái Nguyên is subdivided into 9 district-level sub-divisions and 178 commune-level sub-divisions: There are several tourist attractions in the province. Some of the ones outside the capital city are listed below. Núi Cốc Lake is the most popular attraction. Tour boats circle the lake, recounting local legends and visiting some of the 89 islands within it. Several islands feature historic remains, protected breeding sites for birds, or feral goats. In March 2007, an eco-tourism park
8514-606: The rice cake into portions for sharing. Tết is the village's busiest season. Magma Magma (from Ancient Greek μάγμα ( mágma ) 'thick unguent ') is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as lava ) is found beneath the surface of the Earth , and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites . Besides molten rock, magma may also contain suspended crystals and gas bubbles . Magma
8613-588: The right angle. Otherwise, artificial light is required to see the Hisinterior. Historical Safe Zone (An toàn khu – ATK) locates in Định Hóa district. This was the place where president Ho Chi Minh had lived for several years in The Resistance War against France (1945 -1954) Besides its famous tea, the province is known for such local culinary specialties as bún chả and phở noodle dishes, Định Hóa rice, Dầy cake, and hill chicken. But its most famous food
8712-405: The roof of a magma chamber and fractional crystallization near its base can even take place simultaneously. Magmas of different compositions can mix with one another. In rare cases, melts can separate into two immiscible melts of contrasting compositions. When rock melts, the liquid is a primary magma . Primary magmas have not undergone any differentiation and represent the starting composition of
8811-405: The same composition with no carbon dioxide. Magmas of rock types such as nephelinite , carbonatite , and kimberlite are among those that may be generated following an influx of carbon dioxide into mantle at depths greater than about 70 km. Increase in temperature is the most typical mechanism for formation of magma within continental crust. Such temperature increases can occur because of
8910-442: The same lavas ranges over seven orders of magnitude, from 10 cP (10 Pa⋅s) for mafic lava to 10 cP (10 Pa⋅s) for felsic magmas. The viscosity is mostly determined by composition but is also dependent on temperature. The tendency of felsic lava to be cooler than mafic lava increases the viscosity difference. The silicon ion is small and highly charged, and so it has a strong tendency to coordinate with four oxygen ions, which form
9009-404: The source rock. Some calk-alkaline granitoids may be produced by a high degree of partial melting, as much as 15% to 30%. High-magnesium magmas, such as komatiite and picrite , may also be the products of a high degree of partial melting of mantle rock. Certain chemical elements, called incompatible elements , have a combination of ionic radius and ionic charge that is unlike that of
9108-521: The southwest is the Tam Đảo mountain range, located on the northern fringe of the Red River Delta. The range spans some 80 kilometres, with its highest peak of 1,529 metres (note other sources state 1,590 or 1,592 metres) and many cliffs running from northwest to southeast. The Tam Đảo mountain region is protected by the Tam Đảo National Park , established in 1996, which is one of the largest national parks in
9207-468: The surface and the overburden pressure drops, dissolved gases bubble out of the liquid, so that magma near the surface consists of materials in solid, liquid, and gas phases . Most magma is rich in silica . Rare nonsilicate magma can form by local melting of nonsilicate mineral deposits or by separation of a magma into separate immiscible silicate and nonsilicate liquid phases. Silicate magmas are molten mixtures dominated by oxygen and silicon ,
9306-401: The surface in the first place. The temperature within the interior of the earth is described by the geothermal gradient , which is the rate of temperature change with depth. The geothermal gradient is established by the balance between heating through radioactive decay in the Earth's interior and heat loss from the surface of the earth. The geothermal gradient averages about 25 °C/km in
9405-613: The upward intrusion of magma from the mantle. Temperatures can also exceed the solidus of a crustal rock in continental crust thickened by compression at a plate boundary . The plate boundary between the Indian and Asian continental masses provides a well-studied example, as the Tibetan Plateau just north of the boundary has crust about 80 kilometers thick, roughly twice the thickness of normal continental crust. Studies of electrical resistivity deduced from magnetotelluric data have detected
9504-462: The upward movement of solid mantle is critical in the evolution of the Earth. Decompression melting creates the ocean crust at mid-ocean ridges , making it by far the most important source of magma on Earth. It also causes volcanism in intraplate regions, such as Europe, Africa and the Pacific sea floor. Intraplate volcanism is attributed to the rise of mantle plumes or to intraplate extension, with
9603-467: The viscosity. Higher-temperature melts are less viscous, since more thermal energy is available to break bonds between oxygen and network formers. Most magmas contain solid crystals of various minerals, fragments of exotic rocks known as xenoliths and fragments of previously solidified magma. The crystal content of most magmas gives them thixotropic and shear thinning properties. In other words, most magmas do not behave like Newtonian fluids, in which
9702-544: Was 629,197 while the female population was 657,554. The rural population was 876,484 against an urban population of 410,267 (about 47% of the rural population). There are about 50 ethnic groups in Thái Nguyên recognized by the Vietnamese government. Each ethnicity has their own language, traditions, and subculture. The largest ethnic groups are: Vietnamese (70.13%), followed by Tày , Nùng , Sán Dìu and Sán Chay Demographic distribution varies greatly: population density in
9801-403: Was developed beside the lake. It features musical fountains, an animal park, and a Fairy Tale House Underworld and Water park. Phuong Hoang (Phoenix) cave is one of the largest caves in Vietnam, located at a distance of 40 km from Thái Nguyên city. The cave has four chambers where stalagmite and stalactite formations can be seen. Two of the caves admit some sunlight when the sun is at
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