102-669: The island of Taiwan was formed approximately 4 to 5 million years ago at a convergent boundary between the Philippine Sea Plate and the Eurasian Plate . In a boundary running the length of the island and continuing southwards, the Eurasian Plate is sliding under the Philippine Sea Plate. In the northeast of the island, the Philippine Sea Plate slides under the Eurasian Plate. Most of
204-469: A flood . The rock is enriched in titanium and poor in aluminium, rubidium and strontium. The alkaline basalt contains olivine and analcite . The tholeiite contains plagioclase and pyroxene. The magma originated in the upper mantle under tension conditions on the continental margin. The Philippine Sea Plate is converging with the continent at 7 cm per year in the west north west direction. It has compressed Cenozoic sediments by around 200 km in
306-614: A pelite . Slate can be made into roofing slate, a type of roof tile which are installed by a slater . Slate has two lines of breakability—cleavage and grain—which make it possible to split the stone into thin sheets. When broken, slate retains a natural appearance while remaining relatively flat and easy to stack. A series of "slate booms" occurred in Europe from the 1870s until the First World War following improvements in railway, road and waterway transportation systems. Slate
408-480: A boundary running the length of the island and continuing southwards in the Luzon Volcanic Arc (including Green Island and Orchid Island ), the Eurasian Plate is sliding under the Philippine Sea Plate. Most of the island comprises a huge fault block tilted to the west. The western part of the island, and much of the central range, consists of sedimentary deposits scraped from the descending edge of
510-585: A land bridge during glacial periods . Niushan Island in Nanlai village, Aoqian town, Pingtan County, Fuzhou, Fujian is the closest China (PRC)-administered island to the main island. To the south, the main island is separated from the Philippine island of Luzon by the 250 km (155 mi)-wide Luzon Strait . The South China Sea lies to the southwest, the East China Sea to the north, and
612-453: A light-green, spotted texture. These spheres are sometimes deformed by a subsequent applied stress field into ovoids, which appear as ellipses when viewed on a cleavage plane of the specimen. However, some evidence shows that reduced spots may also form after deformation and acquire an elliptical shape from preferential infiltration along the cleavage direction, so caution is required in using reduction ellipsoids to estimate deformation. Before
714-406: A long-lasting weathertight roof with a lifespan of around 60–125 years. Some mainland European slate suppliers suggest that using hook fixing means that: The metal hooks are, however, visible and may be unsuitable for historic properties. Slate tiles are often used for interior and exterior flooring, stairs, walkways and wall cladding. Tiles are installed and set on mortar and grouted along
816-410: A loss of up to 50% of the volume of the mudrock as it is compacted. Grains of platy minerals, such as clay minerals , are rotated to form parallel layers perpendicular to the direction of compaction, which begin to impart cleavage to the rock. Slaty cleavage is fully developed as the clay minerals begin to be converted to chlorite and mica. Organic carbon in the rock is converted to graphite . Slate
918-569: A magnitude 6.4 earthquake hit southern Taiwan. The seismic hazard map for Taiwan by the USGS shows 9/10 of the island as the highest rating (most hazardous). Island of Taiwan Taiwan , officially the Republic of China (ROC), is a country in East Asia . The island of Taiwan , also known as Formosa , has an area of 35,808 square kilometres (13,826 sq mi) and makes up 99% of
1020-570: A marble canyon, cliff, and fold mountains. Shei-Pa National Park has alpine ecosystems, geological terrain, and valley streams. Kinmen National Park has lakes, wetlands, coastal topography, flora and fauna-shaped island. Dongsha Atoll National Park has the Pratas reef atolls for integrity, a unique marine ecology, and biodiversity, and is a key habitat for the marine resources of the South China Sea and Taiwan Strait. Natural resources on
1122-603: A process which left the crust under Taiwan more buoyant. South of Taiwan, the Sunda Plate is subducting under the Philippine Sea Plate, forming the Luzon Volcanic Arc (including Green Island and Orchid Island ). The east and south of the island are a complex system of belts formed by, and part of the zone of, active collision between the North Luzon Trough portion of the Luzon Volcanic Arc and
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#17327760548141224-439: A property called fissility , forming smooth, flat sheets of stone which have long been used for roofing , floor tiles, and other purposes. Slate is frequently grey in color, especially when seen en masse covering roofs. However, slate occurs in a variety of colors even from a single locality; for example, slate from North Wales can be found in many shades of grey, from pale to dark, and may also be purple, green, or cyan. Slate
1326-570: A rudimentary damp-proof membrane . Small offcuts are used as shims to level floor joists. In areas where slate is plentiful it is also used in pieces of various sizes for building walls and hedges, sometimes combined with other kinds of stone. Because it is a good electrical insulator and fireproof, it was used to construct early-20th-century electric switchboards and relay controls for large electric motors . Because of its thermal stability and chemical inertness, slate has been used for laboratory bench tops and for billiard table tops. Slate
1428-547: Is Cretaceous in age and consists of black schist and some greenschist , glaucophane schist , and spotted slate . It is the easternmost part and extends from Chian southwards to the west of the Chihpen hot springs in a belt about 150 km long. Although the dark colour of the black schist is due to carbon, carbon is less than 2% of the content. The minerals found are quartz, mica , chlorite , albite , sphene , and graphite . The Changchun Schist being mostly greenschist
1530-410: Is 36,197 km (13,976 sq mi), slightly larger than Belgium . It has a coastline of 1,566.3 km (973.3 mi). The ROC claims an exclusive economic zone of 83,231 km (32,136 sq mi) with 200 nmi (370.4 km; 230.2 mi) and a territorial sea of 12 nmi (22.2 km; 13.8 mi). The island of Taiwan, the largest of the archipelago, was known in
1632-422: Is a fine-grained, metamorphic rock that shows no obvious compositional layering but can easily be split into thin slabs and plates. It is usually formed by low-grade regional metamorphism of mudrock . This mild degree of metamorphism produces a rock in which the individual mineral crystals remain microscopic in size, producing a characteristic slaty cleavage in which fresh cleavage surfaces appear dull. This
1734-467: Is a light bluish gray siltstone, with shale and fine grained sandstone. The Maanshan Formation is very similar. It is overlain by Hengchun Limestone and may interfinger. The Hengchun Limestone was formed after the Penglai movement in the third Pleistocene stage. Also at this time laterite (紅土) and gravel on river terraces was formed. Holocene mud sand and coral form a wide belt on the west side of
1836-528: Is also fire resistant and energy efficient. Slate roof tiles are usually fixed (fastened) either with nails or with hooks (as is common with Spanish slate). In the UK, fixing is typically with double nails onto timber battens (England and Wales) or nailed directly onto timber sarking boards (Scotland and Northern Ireland). Nails were traditionally of copper, although there are modern alloy and stainless steel alternatives. Both these methods, if used properly, provide
1938-695: Is between 80 and 400 m thick. The Zhuolan Formation or Cholan Formation (卓蘭層) starts in the Pliocene and extends into the first stage of the Pleistocene . It consists of fine grained sandstone. This is 1.5 to 2.5 km thick. At the same time on the southern tip of the island, the Kending Formation or Kenting Formation (墾丁組) was formed consisting of mudstone with ophiolite melange . The ophiolite melange contains pebbles and blocks of Miocene age consisting of basic and ultrabasic rock from
2040-694: Is divided into two parts: the flat to gently rolling plains in the west, where 90% of the population lives, and the mostly rugged forest-covered mountains in the eastern two-thirds. The eastern part of the island is dominated by five mountain ranges, each running from north-northeast to south-southwest, roughly parallel to the east coast of the island. As a group, they extend 330 km (210 mi) from north to south and average about 80 kilometres (50 mi) from east to west. They include more than two hundred peaks with elevations of over 3,000 m (9,800 ft). The Central Mountain Range extends from Su'ao in
2142-502: Is found on the western side and forms thick beds. It is found along with smaller amounts of chert , and black schist. The rock is foliated dark green rock containing chlorite, epidote , quartz, calcite, biotite, albite and actinolite . They are derived from mafic volcanic rocks . These rocks can host copper sulfide ores. Siliceous schists are coloured grey, they are metamorphosed sandstone, rich in quartz. Quartzite and chert bands can be found, and they are commonly associated with
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#17327760548142244-695: Is in Puli Township , Nantou County . The southernmost point on the island is Cape Eluanbi in Hengchun Township , Pingtung County . The main island is separated from the southeast coast of mainland China by the Taiwan Strait , which ranges from 220 km (140 mi) at its widest point to 130 km (81 mi) at its narrowest. Part of the continental shelf, the Strait is no more than 100 m (330 ft) deep, and has become
2346-442: Is in contrast to the silky cleaved surfaces of phyllite , which is the next-higher grade of metamorphic rock derived from mudstone. The direction of cleavage is independent of any sedimentary structures in the original mudrock, reflecting instead the direction of regional compression. Slaty cleavage is continuous, meaning that the individual cleavage planes are too closely spaced to be discernible in hand samples. The texture of
2448-668: Is made of mud containing blocks of other stone such as sandstone and ophiolite . It is found on the southern half of the west side of the Coastal range. When this erodes, badlands are formed. Because it is a mixture of stone, the Lichi Formation is hard to date, but is likely to be from Pliocene . The Pinanshan conglomerate is found on Pinanshan Hill and along the Pinantachi stream north of Taitung (台東). The constituents are 5–15 cm cobbles erodes by freshwater from
2550-462: Is mainly composed of the minerals quartz, illite , and chlorite, which account for up to 95% of its composition. The most important accessory minerals are iron oxides (such as hematite and magnetite ), iron sulfides (such as pyrite ), and carbonate minerals. Feldspar may be present as albite or, less commonly, orthoclase . Occasionally, as in the purple slates of North Wales , ferrous ( iron(II) ) reduction spheres form around iron nuclei, leaving
2652-486: Is not to be confused with shale, from which it may be formed, or schist . The word "slate" is also used for certain types of object made from slate rock. It may mean a single roofing tile made of slate, or a writing slate , which was traditionally a small, smooth piece of the rock, often framed in wood, used with chalk as a notepad or notice board, and especially for recording charges in pubs and inns. The phrases "clean slate" and " blank slate " come from this usage. Slate
2754-505: Is particularly suitable as a roofing material as it has an extremely low water absorption index of less than 0.4%, making the material resistant to frost damage. Natural slate, which requires only minimal processing, has an embodied energy that compares favorably with other roofing materials. Natural slate is used by building professionals as a result of its beauty and durability. Slate is incredibly durable and can last several hundred years, often with little or no maintenance. Natural slate
2856-401: Is rich in wind energy resources, with wind farms both onshore and offshore, though limited land area favours offshore wind resources. By promoting renewable energy, Taiwan's government hopes to also aid the nascent renewable energy manufacturing industry, and develop it into an export market. Taiwan has a population of over 23 million, the vast majority of whom live in the lowlands near
2958-495: Is up to 1000 m. Dajian Formation consists of sandstone from the upper Eocene, up to 2700 meters thick. Xichun Formation slate and phyllite is from the lower Oligocene. The thickness is from 0.6 to 3 km. Siling Formation coarse sandstone in thick beds is from the Oligocene. Shuichungliu Formation form the Oligocene contains argillaceous slate and graywacke . Bilushan Formation contains slate and phyllite from
3060-799: The Formosan clouded leopard is likely extinct and the otter restricted to Kinmen island . The largest carnivore is the Formosan black bear ( Selanarctos thibetanus formosanus ), a rare and endangered species. Nine national parks in Taiwan showcase the archipelago's diverse terrain, flora and fauna. Kenting National Park on the southern tip of Taiwan contains uplifted coral reefs , moist tropical forest and marine ecosystems. Yushan National Park has alpine terrain, mountain ecology, forest types that vary with altitude, and remains of ancient roads. Yangmingshan National Park has volcanic geology, hot springs, waterfalls, and forest. Taroko National Park has
3162-445: The Formosan landlocked salmon ( Oncorhynchus masou formosanus ). A few of these are now extinct , and many others have been designated endangered species . Taiwan has 65 species of fireflies, the third highest density after Jamaica and Costa Rica. Fireflies are protected and their numbers are increasing, but they are threatened by climate change in the long term. Taiwan had relatively few carnivores , 11 species in total, of which
Geology of Taiwan - Misplaced Pages Continue
3264-529: The Hualien River in the north to Taitung County in the south, and chiefly consist of sandstone and shale. It is separated from the Central Range by the narrow Huatung Valley , at an altitude of 120 m (390 ft). Although Hsinkangshan (新港山), the highest peak, reaches an elevation of 1,682 m (5,518 ft), most of the range is composed of large hills. Small streams have developed on
3366-712: The Linkou Plateau , the Taoyuan Plateau and the Dadu Plateau . About 23% of Taiwan's land area consists of fertile alluvial plains and basins watered by rivers running from the eastern mountains. Over half of this land lies in the Chianan Plain in southwest Taiwan, with lesser areas in the Pingtung Plain , Taichung Basin and Taipei Basin . The only sizable plain on the east coast is
3468-668: The Luzon Volcanic Arc (呂宋島火山弧), and is on the Philippine Sea Plate (菲律賓海板塊). West of this is the Longitudinal Valley or Huatung Valley , an active depositional zone in a rift valley. West of this is the Eastern Central Range terrane, part of the continental base that has been upturned. The western side of the range is the Western Central Range terrane, which is metamorphosed earlier Tertiary clastic sediments. The Lishan Fault separates
3570-684: The Mid North at Mintaro and Spalding . Slate is abundant in Brazil , the world's second-largest producer of slate, around Papagaios in Minas Gerais , which extracts 95 percent of Brazil's slate. However, not all "slate" products from Brazil are entitled to bear the CE mark . Most slate in Europe today comes from Spain , the world's largest producer and exporter of natural slate, and 90 percent of Europe's natural slate used for roofing originates from
3672-632: The Penghu archipelago in the Taiwan Strait, Kinmen and Matsu in Fuchien near the PRC's coast, as well as Pratas and Taiping in the South China Sea. Geologically, the main island comprises a tilted fault block , characterized by the contrast between the eastern two-thirds, consisting mostly of five rugged mountain ranges running parallel to the east coast, and the flat to gently rolling plains of
3774-643: The Philippine Sea to the east. Smaller islands of the archipelago include the Penghu islands in the Taiwan Strait 50 km (31 mi) west of the main island, with an area of 127 km (49 sq mi), the tiny islet of Xiaoliuqiu off the southwest coast, and Orchid Island and Green Island to the southeast, separated from the northernmost islands of the Philippines by the Bashi Channel . The islands of Kinmen and Matsu near
3876-551: The Sun Moon Lake Basin in the centre of the island. The Dadu and Zhuoshui Rivers flow from the western slopes of the Central Range through the basin to the west coast of the island. The Xueshan Range lies to the northwest of the Central Mountain Range, beginning at Sandiaojiao , the northeast tip of the island, and gaining elevation as it extends southwest towards Nantou County . Xueshan ,
3978-889: The World Trade Organization in 2002. Consequently, upon the decline of subsistence, Taiwan's agriculture now relies heavily on the marketing and export of specialty crops, such as bananas , guavas , lychees , bell fruits , and high-mountain tea . Taiwan has significant coal deposits and some insignificant petroleum and natural gas deposits. As of 2010 , oil accounts for 49.0% of the total energy consumption. Coal comes next with 32.1%, followed by nuclear energy with 8.3%, natural gas (indigenous and liquefied) with 10.2%, and energy from renewable sources with 0.5%. Taiwan has six nuclear reactors and two under construction. Nearly all oil and gas for transportation and power needs must be imported, making Taiwan particularly sensitive to fluctuations in energy prices. Taiwan
4080-642: The Yilan Plain in the northeast. The island of Taiwan lies across the Tropic of Cancer , and its climate is influenced by the East Asian Monsoon . Northern Taiwan has a humid subtropical climate , with substantial seasonal variation of temperatures, while parts of central and most of southern Taiwan have a tropical monsoon climate where seasonal temperature variations are less noticeable, with temperatures typically varying from warm to hot. During
4182-518: The 17th century. Camphor extraction and sugar refining played an important role in Taiwan's exports from the late 19th century through the first half of the 20th century. The importance of these industries declined mainly due to the reduction of international demand rather than the exhaustion of related natural resources. Domestic agriculture (rice being the dominant kind of crop) and fisheries retain some importance. Still, they have been greatly challenged by foreign imports since Taiwan's accession to
Geology of Taiwan - Misplaced Pages Continue
4284-409: The Central Mountain Range is the steepest mountain slope in Taiwan, with fault scarps ranging in height from 120 to 1,200 m (390 to 3,900 ft). Taroko National Park , on the steep eastern side of the range, has good examples of mountainous terrain, gorges and erosion caused by a swiftly flowing river. The East Coast Mountain Range extends down the east coast of the island from the mouth of
4386-520: The Central Range. It formed somewhere from middle to late Pleistocene, and indicates the plate collision had taken place. The Milun Conglomerate is to the north of Hualien. This has also gone under the names of Beiron Conglomerate Formation and Milunpi Conglomerate. It is tilted at 30°. It is undated but is likely from Pleistocene. Shibachongxi Formation is from the Eocene consisting of slate and then beds of metamorphosed sandstone. The total thickness
4488-672: The East Rift Valley (花東縱谷) and 1964 Baihe earthquake on the Chukou Fault. The 1946 Hsinhua earthquake ruptured the Hsinhua fault (新化斷層). The most lethal was 1935 Hsinchu-Taichung earthquake shifting on a fault at Emei Township , Hsinchu County . The second deadliest was a 7.3 quake that ruptured the Chelongpu Fault (車籠埔斷層) on 21 September 1999, known as the " 921 earthquake ". On 4 March 2010 at about 01:20 UTC,
4590-462: The Eocene. Lushan Formation from the Miocene contains shale slate and sandstone. Aodi Formation contemporary Sule Formation slate and sandstone from the later Miocene. The west part of the island exposes deformed and metamorphosed Cenozoic sediments, overlaid by Quaternary piedmont region in the flat plains on the west coast. Cretaceous , Paleocene and Eocene deposits are not exposed on
4692-689: The Eurasian Plate, where accreted portions of the Luzon Arc and Luzon forearc form the eastern Coastal Range and parallel inland Taitung Longitudinal Valley of Taiwan respectively. From the northeast of Taiwan and continuing eastwards in the Ryukyu Volcanic Arc, the Philippine Sea Plate is subducting under the Okinawa Plate, forming the Ryukyu Volcanic Arc . The Hai'an Range or Coastal Range terrane belongs to
4794-417: The Eurasian Plate. In the northeast of the island, and continuing eastwards in the Ryukyu Volcanic Arc, the Philippine Sea Plate slides under the Eurasian Plate. The tectonic boundary remains active, and Taiwan experiences 15,000 to 18,000 earthquakes each year, of which 800 to 1,000 are noticed by people. The most catastrophic recent earthquake was the magnitude-7.3 Chi-Chi earthquake , which occurred in
4896-590: The Hsuehshan Range terrane Eocene to Oligocene sandstone and shale. The Chukou Fault (觸口斷層) provides the boundary for the Western Foothills terrane, which is shallow marine detritus from Miocene to Pleistocene. A deformation front forms the boundary with the undeformed coastal plains alluvium, which is still depositing. The Eastern Central Range terrane can be divided into the Tailuko belt on
4998-648: The Miocene. The magma was formed under tension conditions on the continental margin from deep down in the mantle. Volcanoes on the Coastal Range and Green Island erupted tholeiite andesite, and volcanic explosive fragments. The volcanoes erupted from the Pliocene to Pleistocene period. It is part of the Luzon Volcanic Arc . Magma was formed from subducting oceanic crust under compression about 25 km deep. The andesite rock contains some visible crystals of pyroxene or amphibole . The geochemistry of
5100-564: The Ryukyu Volcanic Arc during the Pleistocene. The volcanoes on Chilungshan , Penshan, Caoshan, Chilung Island (Keelung Islet) and Gueishan Island date from the Pleistocene period and later. The eruption were explosive tholeiitic andesite and dacite . The main mineral is calcium rich plagioclase . The magma source is the western extremity of the Ryukyu Volcanic Arc formed when the subducting Philippine Sea Plate
5202-467: The Taiwan Straits. The climate ranges from tropical in the south to subtropical in the north, and is governed by the East Asian Monsoon . On average, four typhoons strike the main island each year. The heavily forested eastern mountains provide a habitat for a diverse range of wildlife, while human land use in the western and northern lowlands is intensive. The total land area of Taiwan
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#17327760548145304-723: The Tsenghuanshan block 10 km west of Juisui are significant ultramafic outcrops. Green serpentinite from near Yuli makes a good quality building stone. A band of ultramafic rocks extends for 25 km north of Litao, Taitung (離島). The area was subjected to the Nanao Orogeny around 85 Ma which involved the granite intrusion and regional metamorphism. Rifting that opened the South China Sea around 40 Ma may be connected with some dolerite intrusions. The Penglai Orogeny started about 10 Ma and continues at
5406-583: The West until after World War II as Formosa , from the Portuguese Ilha Formosa ( [ˌiʎɐ fuɾˈmɔzɐ] ), "beautiful island". It is 394 km (245 mi) long and 144 km (89 mi) wide, and has an area of 35,808 km (13,826 sq mi). The northernmost point of the island is Cape Fugui in New Taipei 's Shimen District . The central point of the island
5508-595: The Yushan Range, across the valley of the south-flowing Kaoping River . The range has major elevations between 1,000 and 2,000 m (3,300 and 6,600 ft). The main peak, Data Mountain (大塔山), towers 2,663 m (8,737 ft). Below the western foothills of the ranges, such as the Hsinchu Hills and the Miaoli Hills , lie raised terraces formed of material eroded from the ranges. These include
5610-401: The black schist. The Chiuchu Formation or Tailuge Marble forms a band from Tailuko in the north to a point between Wulu and Kuanshan in the south. The limestone is mined in quarries south of Suao for cement manufacture. Although the colour is usually a shade of grey, there are also black or white limestone, which is chopped into blocks for building purposes. dolomite is also found along with
5712-668: The calls of all four species of wild turkey in North America: eastern, Rio Grande, Osceola and Merriam's. Slate is found in the Arctic and was used by Inuit to make the blades for ulus . China has vast slate deposits; in recent years its export of finished and unfinished slate has increased. Deposits of slate exist throughout Australia, with large reserves quarried in the Adelaide Hills in Willunga , Kanmantoo , and
5814-529: The camphor laurel ( Cinnamomum camphora ) was once also widespread at lower altitudes. Taiwan is a centre of bird endemism (see List of endemic birds of Taiwan ). Before the country's industrialization , the mountainous areas held several endemic animal species and subspecies, such as the Swinhoe's pheasant ( Lophura swinhoii ), Taiwan blue magpie ( Urocissa caerulea ), the Formosan sika deer ( Cervus nippon taiwanensis or Cervus nippon taiouanus ) and
5916-435: The centre of Taiwan on 21 September 1999, killing more than 2,400 people. On 4 March 2010 at about 01:20 UTC, a magnitude 6.4 earthquake hit southwestern Taiwan in the mountainous area of Kaohsiung County . Another major earthquake occurred on 6 February 2016, with a magnitude of 6.4. Tainan was damaged the most, with 117 deaths, most of them caused by the collapse of a 17-story apartment building. The terrain in Taiwan
6018-580: The coast of Fujian across the Taiwan Strait have a total area of 180 km (69 sq mi); the Pratas and Taiping islets in the South China Sea are also administered by the ROC, but are not part of the Taiwanese archipelago. The island of Taiwan was formed approximately 4 to 5 million years ago at a complex convergent boundary between the Philippine Sea Plate and the Eurasian Plate . In
6120-477: The country of Switzerland. Other environmental issues include water pollution from industrial emissions and raw sewage , contamination of drinking water supplies, trade in endangered species , and low-level radioactive waste disposal. Though regulation of sulfate aerosol emissions from petroleum combustion is becoming stringent, acid rain remains a threat to the health of residents and forests. Atmospheric scientists in Taiwan estimate that more than half of
6222-414: The crust on the island is primarily made up of a series of terranes , mostly old island arcs which have been forced together by the collision of the forerunners of the Eurasian Plate and the Philippine Sea Plate, which is moving to the northwest. These have been further uplifted as a result of the detachment of a portion of the Eurasian Plate as it was subducted beneath remnants of the Philippine Sea Plate,
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#17327760548146324-634: The edges. Chemical sealants are often used on tiles to improve durability and appearance, increase stain resistance, reduce efflorescence , and increase or reduce surface smoothness. Tiles are often sold gauged, meaning that the back surface is ground for ease of installation. Slate flooring can be slippery when used in external locations subject to rain. Slate tiles were used in 19th century UK building construction (apart from roofs) and in slate quarrying areas such as Blaenau Ffestiniog and Bethesda , Wales there are still many buildings wholly constructed of slate. Slates can also be set into walls to provide
6426-550: The exclusive preserve of the indigenous peoples until the early 20th century. A further 1.2 million people from throughout China entered Taiwan at the end of the Chinese Civil War in 1949. Some areas in Taiwan with high population density and many factories are affected by heavy pollution. The most notable areas are the southern suburbs of Taipei and the western stretch from Tainan to Lin Yuan, south of Kaohsiung. By
6528-508: The flanks, but only one large river cuts across the range. Badlands are located at the western foot of the range, where the ground water level is the lowest and rock formations are the least resistant to weathering. Raised coral reefs along the east coast and the frequent occurrences of earthquakes in the rift valley indicate that the fault block is still rising. The ranges to the west of the Central range are divided into two groups separated by
6630-691: The form of tuff and tuffaceous sandstone. These beds are from 100 m to 3 km thick. In the Oligocene the Wuzhishan Formation or Wuchihshan Formation (五指山組) formed thick beds of sandstone. The total thickness is 0.9 to 1.2 km. The Yeliu Group from the Miocene is fine grained sandstone, with some beds of shale, basaltic tuff and three seams of coal . Possibly including Wushan Formation, Piling Shale, Peiliao Formation, Talu shale, Shihti Formation, Kuanyiongshan sandstone. The Ruifang Group contains beds of sandstone, siltstone, shale and six thin coal beds. These beds are 0.8 to 1.6 km thick. The Sangxia Group starts with medium grained sandstone, but in
6732-417: The gneiss there are pegmatite dikes containing quartz, feldspar and mica. Other igneous rocks found in the old metamorphic belt are amphibolite and dolerite dikes. Serpentinite is found 5 km west of Fengtien (奉天). It contains exploited deposits of nephrite , talc and asbestos . Wanjung Station (萬榮) is close to more outcrops of serpentenite. Tamayenshan block northwest of Juisui (瑞穗) and
6834-406: The island comprises a huge fault block tilted to the west. The island is active geologically, formed on a complex convergent boundary between the Yangtze Subplate of the Eurasian Plate to the west and north, the Okinawa Plate on the north-east, the Philippine Sea Plate on the east and south, and the Sunda Plate to the southwest. Subduction changes direction at Taiwan. The upper part of
6936-646: The island's mineral resources (e.g. coal, gold, marble), as well as wild animal reserves (e.g. deer), have been virtually exhausted. Moreover, much of Taiwan's forestry resources , especially firs were harvested during Japanese rule for the construction of shrines and have only recovered slightly since then. To this day, forests do not contribute to significant timber production mainly because of concerns about production costs and environmental regulations. The few natural resources with significant economic value remaining in Taiwan are agriculture-associated. Sugarcane and rice have been cultivated in western Taiwan since
7038-555: The island. The Tatun Volcanic Group is found on the northern tip of Taiwan. Chihsingshan is the highest point of the volcanoes at 1120 meters. The volcanoes have formed the rounded shape of the northern cape of Taiwan. The volcanic rock also occur on Huaping Isle, Mienhua Isle, Pengchia Isle and Huangwei Isle just to the north of Taiwan. The rocks are aluminium rich andesite , tuff and breccia . The rocks are poor in sodium and magnesium, but rich in iron, potassium, rubidium and strontium and strong in rare earth elements. The magma
7140-409: The islands include small deposits of gold , copper , coal , natural gas , limestone , marble , and asbestos . The island is 55% forest and woodland (mostly on the mountains) and 24% arable land (mostly on the plains), with 15% going to other purposes. 5% is permanent pasture and 1% is permanent crops. Because of the intensive exploitation throughout Taiwan's pre-modern and modern history ,
7242-403: The land under ROC control. It lies about 180 kilometres (112 mi) across the Taiwan Strait from the southeastern coast of the People's Republic of China (PRC). The East China Sea is to the north of the island, the Philippine Sea to its east, the Luzon Strait directly to its south, and the South China Sea to its southwest. The ROC also controls a number of smaller islands , including
7344-418: The last 4 Ma . The piled up sediment is rising into mountains at the rate of 5 mm per year. The major seismic faults in Taiwan correspond to the various suture zones between the various terranes. As a result, Taiwan has numerous mud volcanoes and hot springs . These faults have produced several major quakes throughout the history of the island, including the 1951 East Rift Valley earthquakes on
7446-661: The late 20th century, Taipei suffered from extensive vehicle and factory air pollution , but after the government required mandatory use of unleaded petrol and established the Environmental Protection Administration in 1987 to regulate air quality, the air quality of Taiwan has improved dramatically. Motor scooters , especially older or cheaper two-stroke versions, which are ubiquitous in Taiwan, contribute disproportionately to urban air pollution. The Taichung Power Plant also contributes significantly to air pollution, producing more CO 2 than
7548-409: The limestone particularly at Chingchangshan , Hopingchi , and Mukuashan . The Kainangan Gneiss or Kanagan Formation occurs in several elongated bodies. The gneiss derived from sedimentary rocks contains coarse grained quartz, biotite, and albitic plagioclase. There is also orthogneiss derived from granite . This is light grey and contains sodic plagioclase, quartz, biotite, and muscovite. Within
7650-534: The main peak, is 3,886 m (12,749 ft) high. The Yushan Range runs along the southwestern flank of the Central Range. It includes the island's tallest peak, the 3,952 m (12,966 ft) Yu Shan ('Jade Mountain') which makes Taiwan the world's fourth-highest island , and is the highest point in the western Pacific region outside of the Kamchatka Peninsula , New Guinea Highlands and Mount Kinabalu . The Alishan Range lies west of
7752-399: The maximum penalty for ocean pollution was raised from US$ 48,820 to US$ 3.25 million. Slate Slate is a fine-grained, foliated , homogeneous, metamorphic rock derived from an original shale -type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism . It is the finest-grained foliated metamorphic rock. Foliation may not correspond to
7854-509: The mid-19th century, the terms "slate", " shale ", and " schist " were not sharply distinguished. In the context of underground coal mining in the United States, the term slate was commonly used to refer to shale well into the 20th century. For example, roof slate referred to shale above a coal seam , and draw slate referred to shale that fell from the mine roof as the coal was removed. The British Geological Survey recommends that
7956-623: The north to inland of Jinfeng on the eastern flank of the Central Mountain Range . The band is 30 km wide in the north and narrows to the south. These earlier rocks are heavily metamorphosed. They also occur as a basement beneath the western part of the island. They make up the Danana'ao Group or Tananao Schist. This group consists of the Kainanagang Gneiss, Tailuge Marble, and Changchun Schist. The Yuli Schist
8058-489: The northeast to Eluanbi at the southern tip of the island, forming a ridge of high mountains and serving as the island's principal watershed. The mountains are predominantly composed of hard rock formations resistant to weathering and erosion, although heavy rainfall has deeply scarred the sides with gorges and sharp valleys. The relative relief of the terrain is usually extensive, and the forest-clad mountains with their extreme ruggedness are almost impenetrable. The east side of
8160-415: The ocean floor. The interpretation is that a wedge of seafloor was pushed above sea level, eroded and dropped fragments into the mud. The Toukoshan Formation (Toukeshan) (頭嵙山層) commenced with fine sandstone with thin beds of conglomerate, and continued into mainly conglomerate with sandstone beds. This was formed in stage 1 and 2 of the Pleistocene. It is from 0.4 to 3 km thick. The Szekou Formation
8262-417: The original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate, called " slaty cleavage ", is caused by strong compression in which fine-grained clay forms flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation with a specialized tool in the quarry, many slates display
8364-407: The pollutants causing Taiwan's acid rain are carried from China by monsoon winds. Taiwan historically had a serious problem with the illegal dumping of household and industrial waste which became so severe that Taiwan was known as "garbage island." This high level of pollution led to civil and government action, by 2022 the recycling rate was one of the highest in the world at 55%. Community activism
8466-404: The population. Immigrants from southern Fujian began to farm the area around modern Tainan and Kaohsiung from the 17th century, later spreading across the western and northern plains and absorbing the indigenous population of those areas. Hakka people from eastern Guangdong arrived later and settled the foothills further inland, but the rugged uplands of the eastern half of the island remained
8568-758: The present time. The most recently added part of the island is the Coastal Range on the east coast from Taitung City in the south to Hualien City in the north. The range is the continuation of the Luzon arc. The age is Neogene and the rock consist of melange and volcaniclastics . The rock units are firstly Chimei Volcanics Miocene andesite . Next is the Tuluanshan Formation, consisting of tuff , then Takangou Formation, consisting of sediments such as shale and sandstone that contain volcanic particles. The Lichi Formation consists of melange. It
8670-559: The rock shows it is enriched in potassium , strontium and rubidium and light rare earth elements . Chromium and nickel are depleted. The Chimei Volcanic Complex, near the Hsiukuluanchi River , has an age from 9 to 22.2 Ma. It is associated with copper porphyry mineralisation. It covers an area of 22 km. Pleistocene basalt and tholeiite is found in the Penghu Islands . The lava erupted from fissures in
8772-803: The slate from Wales and Cumbria is colored slate (non-blue): purple and formerly green in Wales and green in Cumbria. In North America, slate is produced in Newfoundland , eastern Pennsylvania , Buckingham County, Virginia , and the Slate Valley region in Vermont and New York , where colored slate is mined in the Granville, New York , area. A major slating operation existed in Monson, Maine , during
8874-753: The slate industry there. Lesser slate-producing regions in present-day Europe include Wales (with UNESCO landscape status and a museum at Llanberis ), Cornwall (famously the village of Delabole ), Cumbria (see Burlington Slate Quarries , Honister Slate Mine and Skiddaw Slate ) and, formerly in the West Highlands of Scotland, around Ballachulish and the Slate Islands in the United Kingdom . Parts of France ( Anjou , Loire Valley , Ardennes , Brittany , Savoie ) and Belgium (Ardennes), Liguria in northern Italy , especially between
8976-544: The slate is totally dominated by these pervasive cleavage planes. Under a microscope, the slate is found to consist of very thin lenses of quartz and feldspar (QF-domains) separated by layers of mica (M-domains). These are typically less than 100 μm (micron) thick. Because slate was formed in low heat and pressure, compared to most other metamorphic rocks, some fossils can be found in slate; sometimes even microscopic remains of delicate organisms can be found in slate. The process of conversion of mudrock to slate involves
9078-644: The surface, but are buried. They have been discovered by drilling. The Yunlin Formation is from the Cretaceous and only known from boreholes. The rocks are siltstone, basalt, shale and limestone. The Paleocene Wangong Formation consisting of volcaniclastics , sandstone, shale and limestone is over 1046 meters thick. In the Eocene the Shuangji Formation formed mostly from volcanic particles in
9180-415: The term "slate" be used in scientific writings only when very little else is known about the rock that would allow a more definite classification. For example, if the characteristics of the rock show definitely that it was formed by metamorphosis of shale, it should be described in scientific writings as a metashale. If its origin is uncertain, but the rock is known to be rich in mica, it should be described as
9282-456: The town of Lavagna (whose name is inherited as the term for chalkboard in Italian ) and Fontanabuona valley; Portugal especially around Valongo in the north of the country. Germany 's Moselle River region, Hunsrück (with a former mine open as a museum at Fell ), Eifel , Westerwald , Thuringia and north Bavaria ; and Alta , Norway (actually schist , not a true slate). Some of
9384-665: The upper layers increases shale. Eight thin coal seams are included. The total thickness of the deepest beds exceeds 5 km. This includes the Kueichulin Formation with the Yutengping Sandstone, Shihliufen Shale, Kuantaoshan Sandstone; the Nanchuang Formation including Shangfuchi Sandstone and Tungkeng Formation. The Jinshui Formation or Chinshui Formation from the Pliocene is mostly shale interbedded with some mudstone and sandstone
9486-593: The vegetation on Taiwan ranged from tropical rainforest in the lowlands through temperate forests , boreal forest and alpine plants with increasing altitude. Most of the plains and low-lying hills of the west and north of the island have been cleared for agricultural use since the arrival of the Chinese immigrants during the 17th and 18th century. However the mountain forests are very diverse, with several endemic species such as Formosan cypress ( Chamaecyparis formosensis ) and Taiwan fir ( Abies kawakamii ), while
9588-591: The west with greenschist metamorphism and the Yuli belt on the east with blueschist metamorphism. The two metamorphic belts are possibly separated by a fault called Shoufeng fault, but this is unproven. The oldest exposed rocks are heavily metamorphosed and found in the Central Mountains. Poor quality fossil evidence suggests an origin in the Permian Period. They form a band of rock from Nan'ao in
9690-631: The western coast of the island. The island is highly urbanized, with nearly 9 million people living in the Taipei–Keelung–Taoyuan metropolitan area at the northern end, and over 2 million each in the urban areas of Kaohsiung and Taichung . Taiwanese indigenous peoples comprise approximately 2% of the population, and now mostly live in the mountainous eastern part of the island. Most scholars believe their ancestors arrived in Taiwan by sea between 4000 and 3000 BC, most likely from southeastern China. Han Chinese make up over 95% of
9792-413: The western third, where the majority of the population resides. Several peaks exceed 3,500 m in height - the highest, Yu Shan at 3,952 m (12,966 ft), makes Taiwan the world's fourth-highest island . The tectonic boundary that formed these ranges remains active, and the island experiences many earthquakes, some of them highly destructive. There are also many active submarine volcanoes in
9894-549: The winter (November to March), the northeast experiences steady rain, while the central and southern parts of the island are mostly sunny. The summer monsoon (from May to October) accounts for 90% of the annual precipitation in the south, but only 60% in the north. The average rainfall is approximately 2,600 mm per year. Typhoons are most likely to strike between July and October, with on average about four direct hits per year. Intensive rain from typhoons often leads to disastrous mudslides. Before extensive human settlement,
9996-767: Was compressed below the edge of the Eurasian Plate at about 20 to 30 km deep. The magma was contaminated with continental crust material. Geochemistry of the rock shows that iron, aluminium, titanium, potassium, rubidium and strontium are enriched, but sodium, magnesium and nickel are impoverished. Alkaline volcanic rocks from north west Taiwan are found at the Shihmen Reservoir , Chiaopanshan, Taoyuan and Fuxing. The rocks are picrite , alkaline basalt and trachyandesite . The commons minerals are albite , olivine , clinopyroxene and oxides of iron and titanium. The elements enriched are sodium and titanium, and magnesium and calcium are reduced. The rock dates from
10098-456: Was derived by melting of the underthrust sea plate behind the Ryukyu Volcanic Arc during the Pleistocene . The Caolingshan Basalt consists of olivine and pyroxene, with crystals of biotite and plagioclase. This is rich in K, Rb, Mg, Sr, Cr, and Ni, but poor in Na, Al, and Fe. Rare earth elements are strongly enriched. The magma was derived by deep mantle melting of the underthrust sea plate behind
10200-543: Was key to this change along with innovations such as garbage trucks which play music. Illegal extraction by Chinese sand dredging vessels has caused significant damage to the marine environment of Taiwan's outlying areas. The Taiwan Banks are a particularly hard hit target. Bottom trawling is a controversial practice due to the environmental damage it causes. Bottom trawlers with a tonnage under 50 are restricted from trawling within 5km of shore and those over 50 tons are restricted from trawling within 12km of shore. In 2023
10302-460: Was used by earlier cultures as whetstone to hone knives, but whetstones are nowadays more typically made of quartz. In 18th- and 19th-century schools, slate was extensively used for blackboards and individual writing slates , for which slate or chalk pencils were used. In modern homes slate is often used as table coasters. In areas where it is available, high-quality slate is used for tombstones and commemorative tablets. In some cases slate
10404-482: Was used by the ancient Maya civilization to fashion stelae . Slate was the traditional material of choice for black Go stones in Japan, alongside clamshell for white stones. It is now considered to be a luxury. Pennsylvania slate is widely used in the manufacture of turkey calls used for hunting turkeys. The tones produced from the slate, when scratched with various species of wood striker, imitates almost exactly
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