1.
Yangshuo County
–
Yangshuo County is a county under the jurisdiction of Guilin City, in the northeast of Guangxi Province, China. Its seat is located in Yangshuo Town, surrounded by karst peaks and bordered on one side by the Li River it is easily accessible by bus or by boat from nearby Guilin. In the 1980s, the town popular with foreign backpackers. At that time, domestic tourism represented only a fraction of the tourists. Today, the town has become a destination for both domestic and foreign travelers. The history of West Street dates back to over 1400 years ago, at that time, there were only a few grocery stores in the street. Now, the street has become popular with locals and foreigners alike, there are signs written in both Chinese and English. Due to the high number of foreign visitors to the area many locals in Yangshuo can speak some English. The Yangshuo region has numerous locations for climbing, most easily accessible by bicycle, the most famous of these crags is Moon Hill with several 5.13 graded lines. Other crags of note include Low Mountain, Twin Gates, Baby Frog, The Egg, Bamboo Grove, a digital panorama of the distinctive scenery of Yangshuo was used in the landmark 1993 video game, Doom as one of the backgrounds. Official website of Yangshuo County A comprehensive guide to the city of Yangshuo, focused on lifestyle, travel, culture insights & events in Yangshuo
2.
Guilin
–
Guilin, formerly romanized as Kweilin, is a prefecture-level city in the northeast of Chinas Guangxi Zhuang Autonomous Region. It is situated on the west bank of the Li River and its name means Forest of Sweet Osmanthus, owing to the large number of fragrant sweet osmanthus trees located in the city. The city has long been renowned for its scenery of karst topography and is one of Chinas most popular tourist destinations, in 314 BC, a small settlement was established along the banks of the Li River. During the Qin Dynastys campaigns against the state of Nanyue, the first administration was set up in the area around Guilin. In 111 BC, during the reign of Emperor Wu of the Han Dynasty, Shi An County was established, in AD507, the town was renamed Guizhou. Guilin prospered in the Tang and Song dynasties but remained a county, the city was also a nexus between the central government and the southwest border, and it was where regular armies were placed to guard that border. Canals were built through the city so that supplies could be directly transported from the food-productive Yangtze plain to the farthest southwestern point of the empire. In 1921, Guilin became one of the headquarters of the Northern Expeditionary Army led by Dr. Sun Yat-sen, in 1940, the city acquired its present name. Guilin administers seventeen county-level divisions, including six districts, nine counties and it has a total area of 27,809 square kilometres. The topography of the area is marked by karst formations, the Li River flows through the city. Winter begins dry but becomes progressively wetter and cloudier, spring is generally overcast and often rainy, while summer continues to be rainy though is the sunniest time of year. The monthly 24-hour average temperature ranges from 7.9 °C in January to 28.0 °C in July, and the annual mean is 18.84 °C. The annual rainfall is just above 1,900 mm, and is delivered in bulk from April to June, with monthly percent possible sunshine ranging from 14% in March to 53% in September, the city receives 1,487 hours of bright sunshine annually. Population,4,747,963 Urban population,975,638 Ethnic groups, Zhuang, Yao, Hui, Miao, Han and Dong The GDP per capita was ¥19435 in 2009, ranked no.125 among 659 Chinese cities. However, since the 1950s Guilin has electronics, engineering and agricultural equipment, medicine, rubber, and buses, food processing, including the processing of local agricultural produce, remains the most important industry. More recent and modern industry feature high technology and the tertiary industry characterized by tourism trading, the airport is Guilin Liangjiang International Airport. Arriving to North Station, high-speed trains between Guilin and Changsha and Beijing came into operation in December 2013, in December 2014, high-speed operations began connecting Guangzhou, Shenzhen, Guiyang, and Shanghai. It will bring much convenience for people come to Guilin and it takes only about 2 or 3 hours from Guangzhou to Guilin,7 hours from Shanghai to Guilin and 11 hours from Beijing to Guilin
3.
Chinese language
–
Chinese is a group of related, but in many cases mutually unintelligible, language varieties, forming a branch of the Sino-Tibetan language family. Chinese is spoken by the Han majority and many ethnic groups in China. Nearly 1.2 billion people speak some form of Chinese as their first language, the varieties of Chinese are usually described by native speakers as dialects of a single Chinese language, but linguists note that they are as diverse as a language family. The internal diversity of Chinese has been likened to that of the Romance languages, There are between 7 and 13 main regional groups of Chinese, of which the most spoken by far is Mandarin, followed by Wu, Min, and Yue. Most of these groups are mutually unintelligible, although some, like Xiang and certain Southwest Mandarin dialects, may share common terms, all varieties of Chinese are tonal and analytic. Standard Chinese is a form of spoken Chinese based on the Beijing dialect of Mandarin. It is the language of China and Taiwan, as well as one of four official languages of Singapore. It is one of the six languages of the United Nations. The written form of the language, based on the logograms known as Chinese characters, is shared by literate speakers of otherwise unintelligible dialects. Of the other varieties of Chinese, Cantonese is the spoken language and official in Hong Kong and Macau. It is also influential in Guangdong province and much of Guangxi, dialects of Southern Min, part of the Min group, are widely spoken in southern Fujian, with notable variants also spoken in neighboring Taiwan and in Southeast Asia. Hakka also has a diaspora in Taiwan and southeast Asia. Shanghainese and other Wu varieties are prominent in the lower Yangtze region of eastern China, Chinese can be traced back to a hypothetical Sino-Tibetan proto-language. The first written records appeared over 3,000 years ago during the Shang dynasty, as the language evolved over this period, the various local varieties became mutually unintelligible. In reaction, central governments have sought to promulgate a unified standard. Difficulties have included the great diversity of the languages, the lack of inflection in many of them, in addition, many of the smaller languages are spoken in mountainous areas that are difficult to reach, and are often also sensitive border zones. Without a secure reconstruction of proto-Sino-Tibetan, the structure of the family remains unclear. A top-level branching into Chinese and Tibeto-Burman languages is often assumed, the earliest examples of Chinese are divinatory inscriptions on oracle bones from around 1250 BCE in the late Shang dynasty
4.
Standard Chinese
–
Its pronunciation is based on the Beijing dialect, its vocabulary on the Mandarin dialects, and its grammar is based on written vernacular Chinese. Like other varieties of Chinese, Standard Chinese is a language with topic-prominent organization. It has more initial consonants but fewer vowels, final consonants, Standard Chinese is an analytic language, though with many compound words. There exist two standardised forms of the language, namely Putonghua in Mainland China and Guoyu in Taiwan, aside from a number of differences in pronunciation and vocabulary, Putonghua is written using simplified Chinese characters, while Guoyu is written using traditional Chinese characters. There are many characters that are identical between the two systems, in English, the governments of China and Hong Kong use Putonghua, Putonghua Chinese, Mandarin Chinese, and Mandarin, while those of Taiwan, Singapore, and Malaysia, use Mandarin. The name Putonghua also has a long, albeit unofficial, history and it was used as early as 1906 in writings by Zhu Wenxiong to differentiate a modern, standard Chinese from classical Chinese and other varieties of Chinese. For some linguists of the early 20th century, the Putonghua, or common tongue/speech, was different from the Guoyu. The former was a prestige variety, while the latter was the legal standard. Based on common understandings of the time, the two were, in fact, different, Guoyu was understood as formal vernacular Chinese, which is close to classical Chinese. By contrast, Putonghua was called the speech of the modern man. The use of the term Putonghua by left-leaning intellectuals such as Qu Qiubai, prior to this, the government used both terms interchangeably. In Taiwan, Guoyu continues to be the term for Standard Chinese. The term Putonghua, on the contrary, implies nothing more than the notion of a lingua franca, Huayu, or language of the Chinese nation, originally simply meant Chinese language, and was used in overseas communities to contrast Chinese with foreign languages. Over time, the desire to standardise the variety of Chinese spoken in these communities led to the adoption of the name Huayu to refer to Mandarin and it also incorporates the notion that Mandarin is usually not the national or common language of the areas in which overseas Chinese live. The term Mandarin is a translation of Guānhuà, which referred to the lingua franca of the late Chinese empire, in English, Mandarin may refer to the standard language, the dialect group as a whole, or to historic forms such as the late Imperial lingua franca. The name Modern Standard Mandarin is sometimes used by linguists who wish to distinguish the current state of the language from other northern. Chinese has long had considerable variation, hence prestige dialects have always existed. Confucius, for example, used yǎyán rather than colloquial regional dialects, rime books, which were written since the Northern and Southern dynasties, may also have reflected one or more systems of standard pronunciation during those times
5.
Pinyin
–
Pinyin, or Hànyǔ Pīnyīn, is the official romanization system for Standard Chinese in mainland China, Malaysia, Singapore, and Taiwan. It is often used to teach Standard Chinese, which is written using Chinese characters. The system includes four diacritics denoting tones, Pinyin without tone marks is used to spell Chinese names and words in languages written with the Latin alphabet, and also in certain computer input methods to enter Chinese characters. The pinyin system was developed in the 1950s by many linguists, including Zhou Youguang and it was published by the Chinese government in 1958 and revised several times. The International Organization for Standardization adopted pinyin as a standard in 1982. The system was adopted as the standard in Taiwan in 2009. The word Hànyǔ means the language of the Han people. In 1605, the Jesuit missionary Matteo Ricci published Xizi Qiji in Beijing and this was the first book to use the Roman alphabet to write the Chinese language. Twenty years later, another Jesuit in China, Nicolas Trigault, neither book had much immediate impact on the way in which Chinese thought about their writing system, and the romanizations they described were intended more for Westerners than for the Chinese. One of the earliest Chinese thinkers to relate Western alphabets to Chinese was late Ming to early Qing Dynasty scholar-official, the first late Qing reformer to propose that China adopt a system of spelling was Song Shu. A student of the great scholars Yu Yue and Zhang Taiyan, Song had been to Japan and observed the effect of the kana syllabaries. This galvanized him into activity on a number of fronts, one of the most important being reform of the script, while Song did not himself actually create a system for spelling Sinitic languages, his discussion proved fertile and led to a proliferation of schemes for phonetic scripts. The Wade–Giles system was produced by Thomas Wade in 1859, and it was popular and used in English-language publications outside China until 1979. This Sin Wenz or New Writing was much more sophisticated than earlier alphabets. In 1940, several members attended a Border Region Sin Wenz Society convention. Mao Zedong and Zhu De, head of the army, both contributed their calligraphy for the masthead of the Sin Wenz Societys new journal. Outside the CCP, other prominent supporters included Sun Yat-sens son, Sun Fo, Cai Yuanpei, the countrys most prestigious educator, Tao Xingzhi, an educational reformer. Over thirty journals soon appeared written in Sin Wenz, plus large numbers of translations, biographies, some contemporary Chinese literature, and a spectrum of textbooks
6.
River
–
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water, small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the term river as applied to geographic features. Many names for small rivers are specific to geographic location, examples are run in parts of the United States, burn in Scotland and northeast England. Sometimes a river is defined as being larger than a creek, but not always, Rivers are part of the hydrological cycle. Potamology is the study of rivers while limnology is the study of inland waters in general. Extraterrestrial rivers of liquid hydrocarbons have recently found on Titan. Channels may indicate past rivers on other planets, specifically outflow channels on Mars and rivers are theorised to exist on planets, a river begins at a source, follows a path called a course, and ends at a mouth or mouths. The water in a river is confined to a channel. In larger rivers there is also a wider floodplain shaped by flood-waters over-topping the channel. Floodplains may be wide in relation to the size of the river channel. This distinction between river channel and floodplain can be blurred, especially in areas where the floodplain of a river channel can become greatly developed by housing. Rivers can flow down mountains, through valleys or along plains, the term upriver refers to the direction towards the source of the river, i. e. against the direction of flow. Likewise, the term describes the direction towards the mouth of the river. The term left bank refers to the bank in the direction of flow. The river channel typically contains a stream of water, but some rivers flow as several interconnecting streams of water. Extensive braided rivers are now found in only a few regions worldwide and they also occur on peneplains and some of the larger river deltas. Anastamosing rivers are similar to braided rivers and are quite rare
7.
Guangxi
–
Guangxi, officially the Guangxi Zhuang Autonomous Region, is a Chinese autonomous region in South Central China, bordering Vietnam. Formerly a province, Guangxi became a region in 1958. Guangxis location, in mountainous terrain in the far south of China, has placed it on the frontier of Chinese civilization throughout much of Chinas history, the current name Guang means expanse and has been associated with the region since the creation of Guang Prefecture in 226 AD. It was given provincial level status during the Yuan dynasty, but even into the 20th century it was considered an open, the abbreviation of the region is 桂, which comes from the name of the city of Guilin, the provincial capital during the Ming and Qing dynasties. Originally inhabited by a mixture of groups known to the Chinese as the Baiyue. In 214 BC, the Han Chinese general Zhao Tuo claimed most of southern China for Qin Shi Huang before the emperors death, the ensuing civil war permitted Zhao to establish a separate kingdom at Panyu known as Nanyue Southern Yue. The name Guangxi can be traced to the Expansive or Wide province of the Eastern Wu, Guilin formed one of its commanderies. Under the Tang dynasty, the Zhuang moved to support Piluoges Yi-ruled kingdom of Nanzhao in Yunnan, Guangxi was then divided into an area of Zhuang ascendancy west of Nanning and an area of Han ascendancy east of Nanning. After the collapse of the Southern Zhao, Liu Yan established the Southern Han in Xingwangfu, although this state gained minimal control over Guangxi, it was plagued by instability and annexed by the Song dynasty in 971. The name Guangxi itself can be traced to the Song, who administered the area as the Guangnanxi Circuit, harassed by both Song and the Jiaozhi in modern Vietnam, the Zhuang leader Nong Zhigao led a revolt in 1052 for which he is still remembered by the Zhuang people. His independent kingdom was short-lived, however, and the tattooed Song general Di Qing returned Guangxi to China, the Yuan dynasty established control over Yunnan during its conquest of the Dali Kingdom in 1253 and eliminated the Southern Song following the Battle of Yamen in 1279. Rather than ruling Lingnan as a territory or military district. The area nonetheless continued to be unruly, leading the Ming dynasty to employ the different local groups against one another, at the Battle of Big Rattan Gorge between the Zhuang and the Yao in 1465,20,000 deaths were reported. The Qing dynasty left the region alone until the imposition of rule in 1726. A Yao revolt in 1831 was followed by the Taiping Rebellion in 1850, the execution of St. Auguste Chapdelaine by local officials in Guangxi provoked the Second Opium War in 1858 and the legalization of foreign interference in the interior. Although Louis Brière de lIsle was unable to invade its depot at Longzhou, largely ineffective within Vietnam, it was still able to repulse the French from China itself at the Battle of Zhennan Pass on 23 March 1885. Following the Wuchang Uprising, Guangxi seceded from the Qing Empire on 6 November 1911, the Qing governor, Shen Bingdan, initially remained in place, but was subsequently removed by a mutiny commanded by General Lu Rongting. General Lus Old Guangxi clique overran Hunan and Guangdong as well, Zhuang loyalty made his Self-Government Army cohesive but reluctant to move far beyond its own provinces
8.
China
–
China, officially the Peoples Republic of China, is a unitary sovereign state in East Asia and the worlds most populous country, with a population of over 1.381 billion. The state is governed by the Communist Party of China and its capital is Beijing, the countrys major urban areas include Shanghai, Guangzhou, Beijing, Chongqing, Shenzhen, Tianjin and Hong Kong. China is a power and a major regional power within Asia. Chinas landscape is vast and diverse, ranging from forest steppes, the Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers, the third and sixth longest in the world, respectively, Chinas coastline along the Pacific Ocean is 14,500 kilometers long and is bounded by the Bohai, Yellow, East China and South China seas. China emerged as one of the worlds earliest civilizations in the basin of the Yellow River in the North China Plain. For millennia, Chinas political system was based on hereditary monarchies known as dynasties, in 1912, the Republic of China replaced the last dynasty and ruled the Chinese mainland until 1949, when it was defeated by the communist Peoples Liberation Army in the Chinese Civil War. The Communist Party established the Peoples Republic of China in Beijing on 1 October 1949, both the ROC and PRC continue to claim to be the legitimate government of all China, though the latter has more recognition in the world and controls more territory. China had the largest economy in the world for much of the last two years, during which it has seen cycles of prosperity and decline. Since the introduction of reforms in 1978, China has become one of the worlds fastest-growing major economies. As of 2016, it is the worlds second-largest economy by nominal GDP, China is also the worlds largest exporter and second-largest importer of goods. China is a nuclear weapons state and has the worlds largest standing army. The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. N. Security Council in 1971. China is also a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization, the BCIM, the English name China is first attested in Richard Edens 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. The demonym, that is, the name for the people, Portuguese China is thought to derive from Persian Chīn, and perhaps ultimately from Sanskrit Cīna. Cīna was first used in early Hindu scripture, including the Mahābhārata, there are, however, other suggestions for the derivation of China. The official name of the state is the Peoples Republic of China. The shorter form is China Zhōngguó, from zhōng and guó and it was then applied to the area around Luoyi during the Eastern Zhou and then to Chinas Central Plain before being used as an occasional synonym for the state under the Qing
9.
Karst
–
Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes, the English word karst was borrowed from German Karst in the late 19th century. The German word came into use before the 19th century, according to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic. Scholars disagree, however, on whether the German word was borrowed from Slovene, the Slovene common noun kras was first attested in the 18th century, and the adjective form kraški in the 16th century. The Slovene words arose through metathesis from the reconstructed form *korsъ, ultimately, the word is of Mediterranean origin, believed to derive from some Romanized Illyrian base. It has been suggested that the word may derive from the Proto-Indo-European root karra- rock, the name may also be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps also to Latin Carusardius. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, if this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power. The carbonic acid that causes karstic features is formed as rain passes through the atmosphere picking up carbon dioxide, once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate. The oxidation of sulfides leading to the formation of acid can also be one of the corrosion factors in karst formation. As oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, sulfuric acid then reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is, This reaction chain forms gypsum, the karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath. On exposed surfaces, small features may include solution flutes, runnels, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, foibe, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements, poljes, and karst valleys, mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground systems and extensive caves. Some of the most dramatic of these formations can be seen in Thailands Phangnga Bay, calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide. Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time, in caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals
10.
Xi River
–
The Xi River is the western tributary of the Pearl River in China. It is formed by the confluence of the Gui and Xun Rivers in Wuzhou and it then flows east through Guangdong, and enters the Pearl River Delta just east of the Lingyang Gorge in Zhaoqing. The main branch of the Xi River flows southeast through the delta entering the South China Sea at Modao Men, the major cities along the Xi include Wuzhou, Zhaoqing, and Jiangmen. The other two tributaries of Pearl River are the Dong River and Bei River. The Xi River is navigable for its entire length and it is a commercial waterway of southern China, and links the delta cities to the interior. The entire Xi River system is the largest of the Pearls tributaries at 2,197 kilometres in length and it supplies water to many places in Guangxi, Guangdong and Macau. Other transliterations of the name include Hsi River and Hsi Chiang. Wuzhou Zhaoqing Foshan Heshan Jiangmen Zhongshan Zhuhai WWF - Xi Jiang Rivers and Streams Ecoregion
11.
Tributary
–
A tributary or affluent is a stream or river that flows into a larger stream or main stem river or a lake. A tributary does not flow directly into a sea or ocean, tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. A confluence, where two or more bodies of water together, usually refers to the joining of tributaries. The opposite to a tributary is a distributary, a river or stream that branches off from, distributaries are most often found in river deltas. Right tributary and left tributary are terms stating the orientation of the relative to the flow of the main stem river. These terms are defined from the perspective of looking downstream, where tributaries have the same name as the river into which they feed, they are called forks. These are typically designated by compass direction, for example, the American River receives flow from its North, Middle, and South forks. The Chicago Rivers North Branch has the East, West, and Middle Fork, the South Branch has its South Fork, forks are sometimes designated as right or left. Here, the handedness is from the point of view of an observer facing upstream, for instance, Steer Creek has a left tributary which is called Right Fork Steer Creek. Tributaries are sometimes listed starting with those nearest to the source of the river, the Strahler Stream Order examines the arrangement of tributaries in a hierarchy of first, second, third, and higher orders, with the first-order tributary being typically the least in size. For example, a second-order tributary would be the result of two or more first-order tributaries combining to form the second-order tributary, another method is to list tributaries from mouth to source, in the form of a tree structure, stored as a tree data structure
12.
Pearl River (China)
–
The Pearl River, also known by its Chinese name Zhujiang and formerly often known as the Canton River, is an extensive river system in southern China. The name Pearl River is also used as a catch-all for the watersheds of the Xi, Bei. These rivers are all considered tributaries of the Pearl River because they share a common delta, as well as referring to the system as a whole, the Pearl River name is also applied to a specific branch within the system. This Pearl River is the widest distributary within the delta, although considerably short, the waters that converge east of the Bei Jiang are first referred to as the Pearl River just north of Guangzhou. The Pearl River is famed as the river flows through Guangzhou. The Pearl Rivers estuary, Bocca Tigris, is dredged so as to keep it open for ocean vessels. This bay separates Macau and Zhuhai from Hong Kong and Shenzhen, the Pearl River is so named because of the pearl-colored shells that lie at the bottom of the river in the section that flows through the city of Guangzhou. A500 kV-power line, suspended from three of the tallest pylons in the world, the Pylons of Pearl River Crossing, crosses the river near its mouth. Zhujiang Brewery, one of the three largest domestic breweries in China, is located on the Pearl River Delta within the city of Guangzhou
13.
Wuzhou
–
Wúzhōu, formerly Ngchow, is a prefecture-level city in the east of Guangxi Zhuang Autonomous Region, Peoples Republic of China. Wuzhou is located in eastern Guangxi bordering Guangdong province and it is at the confluence of the Gui River and the Xun River where they form the Xi River, 85% of all water in Guangxi flows through Wuzhou. The total area of Wuzhou is 12,588 km2, the Tropic of Cancer bisects the city. Despite its latitude, Wuzhou has a humid subtropical climate, with short, mild winters. Winter begins dry but becomes progressively wetter and cloudier, spring is generally overcast and often rainy, while summer continues to be rainy though is the sunniest time of year. The monthly 24-hour average temperature ranges from 12.7 °C in January to 29.1 °C in July, and the annual mean is 21.91 °C. The annual rainfall is around 1,450 mm, and is delivered in bulk from April to June, with monthly percent possible sunshine ranging from 17% in March to 55% in July, the city receives 1,738 hours of bright sunshine annually. According to the 2010 Census, the city of Wuzhou has 3,273,300 inhabitants. The population is 13. 22% higher than in 2000, the dominant ethnic group in the prefecture-level city is Han Chinese but there are also Zhuang, Yao and others. Wuzhou has 1 county-level city,3 counties, and 3 districts, dieshan District was abolished on 2013 Amongst the agricultural products produced in the region of Wuzhou, one of the most favoured snacks is Wuzhou honey date. Guilinggao jelly is described as a Wuzhou delicacy. Bingquan Soybean Milk is also welcomed by people and is in the list of choices for breakfast. Wuzhou has become a hub of the gemstone trade, particularly specializing in corundum, spinel
14.
Lingqu
–
The Lingqu Canal is located in Xingan County, near Guilin, in the northwestern corner of Guangxi Province, China. It connects the Xiang River with the Li River, and thus is part of a waterway between the Yangtze and the Pearl River Delta. It was the first canal in the world to connect two river valleys and enabled ships to travel 2,000 kilometres from the latitude of Beijing to Hong Kong. In 214 BC, Qin Shi Huang, the First Emperor of the Qin Dynasty, ordered the construction of a canal connecting the Xiang, the architect who designed the canal was Shi Lu. It is the oldest contour canal in the world, receiving its water from the Xiang and its design also served water conservation by diverting up to a third of the flow of the Xiang to the Li. The canal has been placed on the UNESCO World Heritage Sites tentative List, grand Canal of China Dujiangyan Irrigation System Zhengguo Canal Day, Lance and McNeil, Ian. Biographical Dictionary of the History of Technology
15.
Xiang River
–
The Xiang River, formerly romanized as the Siang Kiang and now also known as the Xiangjiang, is a river in southern China. The rivers name and character is used as the Chinese abbreviation for Hunan, originating from Haiyang Mountain in Lingui of Guangxi, the Xiang is the largest river in Hunan and one of the largest tributaries of Yangtze River. It is 856 kilometers long and 670 kilometers of it is in Hunan, people say the Xiang and the Lijiang River share the same origin, because the upper reaches of the two rivers are connected by the ancient Lingqu Canal, which is located in Xingan County, Guangxi. According to a saying, 70% of the water in Lingqu flows into the Xiang. In the past, the canal, along with the Xiang River and they are said to have been the daughters of the legendary ruler Yao and the wives of his successor Shun. Unable to bear the pain of their husbands death, they committed suicide in this river, an etiological myth relates the spots on the spotted bamboo, also known as the Xiang bamboo, Xiang Consort bamboo, and teardrop bamboo, to the tears of the weeping consorts. They were worshipped in some form by the people of Chu during the Warring States, the late Tang Dynasty poet Yu Wuling is supposed to have been fond of the scenery along the Xiang River. The classic Chinese novel The Dream of the Red Chamber includes a character Shi Xiangyun who takes one of the characters of her name from the river, mao Zedongs Shian Kian Weekly Review, founded on 14 June 1919, publicized Marxism in Changsha. Hengyang Zhuzhou Xiangtan Changsha Dongting Lake List of Chinese rivers Xiaoxiang Xiang River, ueki, Hisayuki, Uno, Naoto, Matsubara, Akira. Matsuura, Tomohisa, ed. Kanshi no Jiten 漢詩の事典, Xiang Jiang at GEOnet Names Server
16.
Yangtze
–
The Yangtze River, known in China as the Cháng Jiāng or the Yángzǐ Jiāng, is the longest river in Asia and the third-longest in the world. The river is the longest in the world to flow entirely within one country and it drains one-fifth of the land area of the Peoples Republic of China and its river basin is home to one-third of the countrys population. The Yangtze is the sixth-largest river by volume in the world. The Yangtze River plays a role in the history, culture. The prosperous Yangtze River Delta generates as much as 20% of the PRCs GDP, for thousands of years, the river has been used for water, irrigation, sanitation, transportation, industry, boundary-marking and war. The Three Gorges Dam on the Yangtze River is the largest hydro-electric power station in the world, in recent years, the river has suffered from industrial pollution, agricultural run-off, siltation, and loss of wetland and lakes, which exacerbates seasonal flooding. Some sections of the river are now protected as nature reserves, a stretch of the upstream Yangtze flowing through deep gorges in western Yunnan is part of the Three Parallel Rivers of Yunnan Protected Areas, a UNESCO World Heritage Site. In mid-2014 the Chinese government announced it was building a transport network, comprising railways, roads and airports. Because the source of the Yangtze was not ascertained until modern times, Yangtze was actually the name of Chang Jiang for the lower part from Nanjing to the river mouth at Shanghai. In modern Chinese, Yangtze is still used to refer to the part of Chang Jiang from Nanjing to the river mouth. Yangtze never stands for the whole Chang Jiang, Chang Jiang is the modern Chinese name for the lower 2,884 km of the Yangtze from its confluence with the Min River at Yibin in Sichuan Province to the river mouth at Shanghai. Chang Jiang literally means the Long River, in Old Chinese, this stretch of the Yangtze was simply called Jiang/Kiang 江, a character of phono-semantic compound origin, combining the water radical 氵 with the homophone 工. Krong was probably a word in the Austroasiatic language of local peoples such as the Yue, similar to *krong in Proto-Vietnamese and krung in Mon, all meaning river, it is related to modern Vietnamese sông and Khmer kôngkea. By the Han Dynasty, Jiang had come to any river in Chinese. The epithet 長, means long, was first formally applied to the river during the Six Dynasties period, various sections of Chang Jiang have local names. From Yibin to Yichang, the river through Sichuan and Chongqing Municipality is also known as the Chuan Jiang or Sichuan River, in the Hubei Province, the river is also called the Jing Jiang or the Jing River after Jingzhou. In Anhui Province, the takes on the local name Wan Jiang after the shorthand name for Anhui. And Yangzi Jiang t 揚子江s 扬子江, p Yángzǐjiāng) or the Yangzi River, the name likely comes from an ancient ferry crossing called Yangzi or Yangzijin
17.
Pearl River Delta
–
The Pearl River Delta, also known as Zhujiang Delta or Zhusanjiao, is the low-lying area surrounding the Pearl River estuary, where the Pearl River flows into the South China Sea. It is one of the most densely urbanized regions in the world and is a hub of China. This region is considered an emerging megacity. The nine largest cities of PRD had a population of 57.15 million at the end of 2013. According to the World Bank Group, the PRD has become the largest urban area in the world in size and population. The river delta, also known as the Golden Delta of Guangdong, is formed by three rivers, the Xi Jiang, Bei Jiang, and Dong Jiang. The flat lands of the delta are criss-crossed by a network of tributaries and distributaries of the Pearl River, the Pearl River Delta is actually two alluvial deltas, separated by the core branch of the Pearl River. The Bei Jiang and Xi Jiang converge to flow into the South China Sea and Pearl River in the west, the Xi Jiang begins exhibiting delta-like characteristics as far west as Zhaoqing, although this city is not usually considered a part of the PRD region. After passing through the Lingyang Gorge and converging with the Bei Jiang, major distributaries of the Xi include Donghui Shuidao, Jiya Shuidao, Hutiaomen Shuidao, Yinzhou Hu, and the main branch of the Xi Jiang. Jiangmen and Zhongshan are the major found in the western section of the delta. The Bei Jiang enters the plains at Qingyuan but doesnt begin to split until near Sanshui. From here the two main distributaries are Tanzhou Shuidao and Shunde Shuidao which form multiple mouths along the west side of the Pearl Rivers estuary. Two other distributaries, Lubao Yong and Xinan Yong, split from the Bei further north, the other major city in the north section of the delta is Foshan. The Dong Jiang flows through Huizhou into the delta and it begins diverging northeast of Dongguan into many distributaries, including the Dongguan Shuidao. Distributuares enter the Pearl River as far north as Luogang and as far south as Hu Men, saltwater crocodiles were present within the Pearl River estuary during antiquity. The eastern side of the PRD, dominated by foreign capital, is the most developed economically, the western areas, dominated by local private capital, are open for development. New transport links between Hong Kong, Macau and Zhuhai in the PRD are expected to open up new areas for development, further integrate the cities, and facilitate trade within the region. 1985, the PRD had been dominated by farms and small rural villages, but after the economy was reformed and opened
18.
Cormorant fishing
–
Cormorant fishing is a traditional fishing method in which fishermen use trained cormorants to fish in rivers. Historically, cormorant fishing has taken place in Japan and China since about 960 AD and it is described as a method used by the ancient Japanese in the Book of Sui, the official history of the Sui Dynasty of China, completed in 636 AD. This technique has also used in other countries but is currently under threat in China. To control the birds, the tie a snare near the base of the birds throat. This prevents the birds from swallowing larger fish, which are held in their throat, when a cormorant has caught a fish in its throat, the fisherman brings the bird back to the boat and has the bird spit the fish up. Though cormorant fishing once was an industry, its primary use today is to serve the tourism industry. The types of cormorants used differ based on the location, in Gifu, Japan, the Japanese cormorant is used, Chinese fishermen often employ great cormorants. Darters, which are close relatives of cormorants, are also used for this fishing technique on occasion. In Guilin, China, cormorant birds are famous for fishing on the shallow Lijiang River. Cormorant fishing is an old tradition in Greece and Macedonia, especially on Doiran Lake which lies in the border of the two countries, and it is practiced today by some traditional fishermen. In Western Europe, cormorant fishing took place briefly from the 16th to 17th centuries, primarily in England, though the fishing method is similar to those used in Japan and China, the European method was developed independently and was closely related to falconry. Cormorant fishing, called ukai in Japanese, takes place in 13 cities in Japan, the most famous location is Gifu, Gifu Prefecture, home to cormorant fishing on the Nagara River, which has continued uninterrupted for the past 1,300 years. Cormorant fishing in Seki also takes place on the Nagara River, only the cormorant fishing masters in Gifu and Seki are employed by the emperor and called Imperial Fishermen of the Royal Household Agency
19.
Bird intelligence
–
Bird intelligence deals with the definition of intelligence and its measurement as it applies to birds. Traditionally, birds have been considered inferior in intelligence to humans and still are, the difficulty of defining or measuring intelligence in non-human animals makes the subject difficult for scientific study. Anatomically, a bird has a large brain compared to its head size. The visual and auditory senses are well developed in most species, while the tactile, Birds communicate using visual signals as well as through the use of calls and song. The testing of intelligence is based on studying the responses to sensory stimuli. Bird intelligence has been studied through several attributes and abilities, many of these studies have been on birds such as quail, domestic fowl and pigeons kept under captive conditions. It has, however, been noted that studies have been limited. Counting has been considered an ability that shows intelligence, anecdotal evidence from the 60s has suggested that crows may count up to 3. Researchers however need to be cautious and ensure that birds are not merely demonstrating the ability to subitize, some studies, such as one done at Moscow State University, have suggested that crows may indeed have a true numerical ability. It has been shown that parrots can count up to 6, cormorants used by Chinese fishermen that were given every eighth fish as a reward were found to be able to keep count up to seven. Hoh wrote in Natural History magazine, In the 1970s, on the Li River, Pamela Egremont observed fishermen who allowed the birds to eat every eighth fish they caught. Writing in the Biological Journal of the Linnean Society, she reported that, once their quota of seven fish was filled and they ignore an order to dive and even resist a rough push or a knock, sitting glum and motionless on their perches. Meanwhile, other birds that had not filled their quotas continued to fish as usual. One is forced to conclude that these intelligent birds can count up to seven. Many birds are able to detect changes in the number of eggs in their nest. Parasitic cuckoos are known to remove one of the host eggs before laying their own. Also, A common test of intelligence is the detour test, most mammals discover that the objective is reached by first going away from the target. Whereas domestic fowl fail on this test, many within the family are able to readily solve the problem
20.
Alluvium
–
Alluvium is loose, unconsolidated soil or sediments, which has been eroded, reshaped by water in some form, and redeposited in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand, when this loose alluvial material is deposited or cemented into a lithological unit, or lithified, it is called an alluvial deposit. The term alluvium is not typically used in situations where the formation of the sediment can clearly be attributed to another process that is well described. This includes, lake sediments, river sediments, or glacially-derived sediments, sediments that are formed or deposited in a perennial stream or river are typically not referred to as alluvial. Most alluvium is very young, and is often referred to as cover because these sediments obscure the underlying bedrock. Most sedimentary material that fills a basin that is not lithified is typically lumped together as alluvial, alluvium of Pliocene age occurs, for example, in parts of Idaho. Alluvium of late Miocene age occurs, for example, in the valley of the San Joaquin River, alluvium can contain valuable ores such as gold and platinum and a wide variety of gemstones. Such a concentration of ores is termed a placer deposit
21.
Sorting (sediment)
–
Sorting describes the distribution of grain size of sediments, either in unconsolidated deposits or in sedimentary rocks. This should not be confused with crystallite size, which refers to the size of a crystal in a solid. Crystallite is the block of a grain. Very poorly sorted indicates that the sediment sizes are mixed, whereas well sorted indicates that the sediment sizes are similar, in the field, sedimentologists use graphical charts to accurately describe the sorting of a sediment using one of these words. The degree of sorting may also indicate the energy, rate, and/or duration of deposition, sorting of sediments can also be affected by reworking of the material after deposition, for instance, by winnowing. Well sorted rocks are generally porous, while poorly sorted rocks have low porosity, grain size Graded bedding Rounding Porosity Soil texture Sediment transport
22.
Gravel
–
Gravel /ˈɡrævəl/ is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel is categorized by the Udden-Wentworth scale into granular gravel and pebble gravel, one cubic metre of gravel typically weighs about 1,800 kg. Gravel is an important commercial product, with a number of applications, many roadways are surfaced with gravel, especially in rural areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac, both sand and small gravel are also important for the manufacture of concrete. Large gravel deposits are a geological feature, being formed as a result of the weathering. The action of rivers and waves tends to pile up gravel in large accumulations and this can sometimes result in gravel becoming compacted and concreted into the sedimentary rock called conglomerate. Where natural gravel deposits are insufficient for human purposes, gravel is often produced by quarrying and crushing hard-wearing rocks, such as sandstone, limestone, quarries where gravel is extracted are known as gravel pits. Southern England possesses particularly large concentrations of them due to the deposition of gravel in the region during the Ice Ages. As of 2006, the United States is the leading producer and consumer of gravel. The word gravel comes from the Breton language, adding the -el suffix in Breton denotes the component parts of something larger. Thus gravel means the stones which make up such a beach on the coast. Many dictionaries ignore the Breton language, citing Old French gravele or gravelle, Gravel often has the meaning a mixture of different size pieces of stone mixed with sand and possibly some clay. American English also allows small stones without sand mixed in also known as crushed stone, types of gravel include, Bank gravel, naturally deposited gravel intermixed with sand or clay found in and next to rivers and streams. Also known as Bank run or River run, bench gravel, a bed of gravel located on the side of a valley above the present stream bottom, indicating the former location of the stream bed when it was at a higher level. Creek rock, this is rounded, semi-polished stones, potentially of a wide range of types. It is also used as concrete aggregate and less often as a paving surface. Crushed stone, rock crushed and graded by screens and then mixed to a blend of stones and fines and it is widely used as a surfacing for roads and driveways, sometimes with tar applied over it. Crushed stone may be made from granite, limestone, dolomite, also known as crusher run, DGA QP, and shoulder stone
23.
Silty
–
Silt is granular material of a size between sand and clay, whose mineral origin is quartz and feldspar. Silt may occur as a soil or as sediment mixed in suspension with water in a body of such as a river. It may also exist as soil deposited at the bottom of a water body, Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt usually has a floury feel when dry, and a slippery feel when wet, Silt can be visually observed with a hand lens. Silt is created by a variety of physical processes capable of splitting the generally sand-sized quartz crystals of primary rocks by exploiting deficiencies in their lattice and these involve chemical weathering of rock and regolith, and a number of physical weathering processes such as frost shattering and haloclasty. The main process is abrasion through transport, including fluvial comminution, aeolian attrition and it is in semi-arid environments that substantial quantities of silt are produced. Silt is sometimes known as rock flour or stone dust, especially produced by glacial action. Mineralogically, silt is composed mainly of quartz and feldspar, sedimentary rock composed mainly of silt is known as siltstone. Liquefaction created by an earthquake is silt suspended in water that is hydrodynamically forced up from below ground level. In the Udden–Wentworth scale, silt particles range between 0.0039 and 0.0625 mm, larger than clay but smaller than sand particles, ISO14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the size in all dimensions, furthermore. Clays are formed from thin plate-shaped particles held together by electrostatic forces, according to the U. S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization, in the Unified Soil Classification System and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size. Silts and clays are distinguished mechanically by their plasticity, Silt is easily transported in water or other liquid and is fine enough to be carried long distances by air in the form of dust. Thick deposits of silty material resulting from deposition by aeolian processes are called loess. Silt and clay contribute to turbidity in water, Silt is transported by streams or by water currents in the ocean. When silt appears as a pollutant in water the phenomenon is known as siltation, Silt, deposited by annual floods along the Nile River, created the rich, fertile soil that sustained the Ancient Egyptian civilization. In south east Bangladesh, in the Noakhali district, cross dams were built in the 1960s whereby silt gradually started forming new land called chars, the district of Noakhali has gained more than 28 square miles of land in the past 50 years
24.
Sand
–
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than gravel and coarser than silt, Sand can also refer to a textural class of soil or soil type, i. e. a soil containing more than 85% sand-sized particles by mass. The second most common type of sand is calcium carbonate, for example aragonite, for example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non renewable resource over human timescales, and sand suitable for making concrete is in high demand, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this size is termed a sand grain. Sand grains are between gravel and silt, a 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers. ISO14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size, very fine sand, fine sand, medium sand, coarse sand, and very coarse sand. These sizes are based on the Krumbein phi scale, where size in Φ = -log2D, on this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers. The composition of sand is highly variable, depending on the local rock sources. The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop. Some sands contain magnetite, chlorite, glauconite or gypsum, Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basaltic with a high olivine content, many sands, especially those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, the study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is weathered from granite or gneiss quartz crystals will be angular. It is called grus in geology or sharp sand in the trade where it is preferred for concrete. Sand that is transported long distances by water or wind will be rounded, people who collect sand as a hobby are known as arenophiles
25.
Floodplain
–
In other words, a floodplain is an area near a river or a stream which floods when the water level reaches flood stage. Flood plains are made by a meander eroding sideways as it travels downstream, when a river breaks its banks and floods, it leaves behind layers of alluvium. These gradually build up to create the floor of the flood plain, floodplains generally contain unconsolidated sediments, often extending below the bed of the stream. These are accumulations of sand, gravel, loam, silt, and/or clay, and are often important aquifers, geologically ancient floodplains are often represented in the landscape by fluvial terraces. These are old floodplains that remain relatively high above the present floodplain and it is probable that any section of such an alluvial plain would show deposits of a similar character. The floodplain during its formation is marked by meandering or anastomotic streams, oxbow lakes and bayous, marshes or stagnant pools, and is occasionally completely covered with water. When the drainage system has ceased to act or is diverted for any reason. The floodplain differs, however, because it is not altogether flat and it has a gentle slope downstream, and often, for a distance, from the side towards the center. The floodplain is the place for a river to dissipate its energy. Meanders form over the floodplain to slow down the flow of water, in terms of flood management the upper part of the floodplain is crucial as this is where the flood water control starts. Artificial canalisation of the river here will have a impact on wider flooding. This is the basis of flood management. Floodplains can support particularly rich ecosystems, both in quantity and diversity, tugay forests form an ecosystem associated with floodplains, especially in Central Asia. They are a category of riparian zones or systems, a floodplain can contain 100 or even 1,000 times as many species as a river. Microscopic organisms thrive and larger species enter a rapid breeding cycle, opportunistic feeders move in to take advantage. The production of nutrients peaks and falls away quickly, however the surge of new growth endures for some time and this makes floodplains particularly valuable for agriculture. River flow rates are undergoing change following suit with climate change and this change is a threat to the riparian zones and other flood plain forests. These forests have over time synced their seedling deposits after the peaks in flow to best take advantage of the nutrient rich soil generated by peak flow
26.
Terrace (geology)
–
In geology, a terrace is a step-like landform. A terrace consists of a flat or gently sloping surface, called a tread, that is typically bounded one side by a steeper ascending slope. The tread and the descending slope together constitute the terrace. Terraces can also consist of a tread bounded on all sides by a riser or scarp. A narrow terrace is called a bench. The sediments underlying the tread and riser of a terrace are also commonly, terraces are formed in various ways. Fluvial terraces are remnants of the floodplain of a stream or river. They are formed by the downcutting of a river or stream channel into, the most common sources of the variations in rivers and streams that create fluvial terraces are vegetative, geomorphic, and hydrologic responses to climate. More recently, the modification of rivers and streams and their watersheds by cultural processes have result in the development of terraces along many rivers. Kame terraces are formed on the side of a valley and are the deposits of meltwater streams flowing between the ice and the adjacent valley side. A marine terrace represents the shoreline of a sea or ocean. The formation of a marine terrace follows this process, A wave cut platform must be carved into bedrock. Although this is the first step to the process for the formation of a marine terrace, after the wave cut platform is formed it must be removed from interaction with the high wave energy. This process happens by either change in sea level due to glacial-interglacial cycles or tectonically rising landmasses, when the wave cut has been raised above sea level it is preserved. The terraces are most commonly preserved in flights along the coastline, a lake terrace represents the former shoreline of either a nonglacial, glacial, or proglacial lake. Given the smaller size of lakes relative to the size of marine water bodies, lake terraces are overall significantly narrower. However, not all lake terraces are relict shorelines, in case of the lake terraces of ancient ice-walled lakes, some proglacial lakes, and alluvium-dammed lakes, they often represent the relict bottom of these lakes. Finally, glaciolacustrine kame terraces are either the relict deltas or bottoms of ancient ice marginal lakes, in geomorphology, a structural terrace is a terrace created by the differential erosion of flat-lying or nearly flat-lying layered strata
27.
Devonian
–
The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian,419.2 million years ago, to the beginning of the Carboniferous,358.9 Mya. It is named after Devon, England, where rocks from this period were first studied, the first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents, by the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established, Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fish. The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every aquatic environment. The ancestors of all four-limbed vertebrates began adapting to walking on land, as their strong pectoral, in the oceans, primitive sharks became more numerous than in the Silurian and Late Ordovician. The first ammonites, species of molluscs, appeared, trilobites, the mollusk-like brachiopods and the great coral reefs, were still common. The Late Devonian extinction which started about 375 million years ago severely affected marine life, killing off all placodermi, and all trilobites, save for a few species of the order Proetida. The palaeogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, while the rock beds that define the start and end of the Devonian period are well identified, the exact dates are uncertain. According to the International Commission on Stratigraphy, the Devonian extends from the end of the Silurian 419.2 Mya, another common term is Age of the Fishes, referring to the evolution of several major groups of fish that took place during the period. Older literature on the Anglo-Welsh basin divides it into the Downtonian, Dittonian, Breconian and Farlovian stages, in the Late Devonian, by contrast, arid conditions were less prevalent across the world and temperate climates were more common. The Devonian Period is formally broken into Early, Middle and Late subdivisions, the rocks corresponding to those epochs are referred to as belonging to the Lower, Middle and Upper parts of the Devonian System. Early Devonian The Early Devonian lasted from 419.2 ±2.8 to 393.3 ±2.5 and began with the Lochkovian stage, which lasted until the Pragian. It spanned from 410.8 ±2.8 to 407.6 ±2.5, and was followed by the Emsian, which lasted until the Middle Devonian began,393. 3±2.7 million years ago. Middle Devonian The Middle Devonian comprised two subdivisions, first the Eifelian, which gave way to the Givetian 387. 7±2.7 million years ago. Late Devonian Finally, the Late Devonian started with the Frasnian,382.7 ±2.8 to 372.2 ±2.5, during which the first forests took shape on land. The first tetrapods appeared in the record in the ensuing Famennian subdivision. This lasted until the end of the Devonian,358. 9±2.5 million years ago, the Devonian was a relatively warm period, and probably lacked any glaciers
28.
Carboniferous
–
The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago, to the beginning of the Permian Period,298.9 Mya. The name Carboniferous means coal-bearing and derives from the Latin words carbō and ferō, and was coined by geologists William Conybeare and William Phillips in 1822. Based on a study of the British rock succession, it was the first of the system names to be employed. The Carboniferous is often treated in North America as two periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial life was established by the Carboniferous period. Amphibians were the dominant land vertebrates, of one branch would eventually evolve into amniotes. Arthropods were also common, and many were much larger than those of today. Vast swaths of forest covered the land, which would eventually be laid down, the atmospheric content of oxygen also reached their highest levels in geological history during the period, 35% compared with 21% today, allowing terrestrial invertebrates to evolve to great size. A major marine and terrestrial extinction event, the Carboniferous rainforest collapse, occurred in the middle of the period, the later half of the period experienced glaciations, low sea level, and mountain building as the continents collided to form Pangaea. In the United States the Carboniferous is usually broken into Mississippian and Pennsylvanian subperiods, the Silesian is roughly contemporaneous with the late Mississippian Serpukhovian plus the Pennsylvanian. In Britain the Dinantian is traditionally known as the Carboniferous Limestone, the Namurian as the Millstone Grit, and the Westphalian as the Coal Measures and Pennant Sandstone. There was also a drop in south polar temperatures, southern Gondwanaland was glaciated throughout the period and these conditions apparently had little effect in the deep tropics, where lush swamps, later to become coal, flourished to within 30 degrees of the northernmost glaciers. Mid-Carboniferous, a drop in sea level precipitated a major extinction, one that hit crinoids. This sea level drop and the unconformity in North America separate the Mississippian subperiod from the Pennsylvanian subperiod. This happened about 323 million years ago, at the onset of the Permo-Carboniferous Glaciation, the Carboniferous was a time of active mountain-building, as the supercontinent Pangaea came together. The southern continents remained tied together in the supercontinent Gondwana, which collided with North America–Europe along the present line of eastern North America, in the same time frame, much of present eastern Eurasian plate welded itself to Europe along the line of the Ural mountains. Most of the Mesozoic supercontinent of Pangea was now assembled, although North China, the Late Carboniferous Pangaea was shaped like an O. There were two major oceans in the Carboniferous—Panthalassa and Paleo-Tethys, which was inside the O in the Carboniferous Pangaea, other minor oceans were shrinking and eventually closed - Rheic Ocean, the small, shallow Ural Ocean and Proto-Tethys Ocean
29.
Limestone
–
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may also form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
30.
Basin (geology)
–
A structural basin is a large-scale structural formation of rock strata formed by tectonic warping of previously flat-lying strata. Structural basins are geological depressions, and are the inverse of domes, some elongated structural basins are also known as synclines. Basins may appear on a map as roughly circular or elliptical. Because the strata dip toward the center, the strata in a basin are progressively younger from the outside in. Basins are often large in extent, often hundreds of kilometers across. Structural basins are important sources of coal, petroleum, and groundwater. The Changing Earth, Exploring Geology and Evolution, 2nd ed. Belmont, Wadsworth Publishing Company,1997
31.
Cenozoic
–
The Cenozoic Era is the current and most recent of the three Phanerozoic geological eras, following the Mesozoic Era and covering the period from 66 million years ago to the present day. The Cenozoic is also known as the Age of Mammals, because of the mammals that dominated, such as Entelodont, Paraceratherium. The extinction of many large groups such as non-avian dinosaurs, Plesiosauria and Pterosauria allowed the mammals and birds to greatly diversify. Early in the Cenozoic, following the K-Pg event, the planet was dominated by relatively small fauna, including mammals, birds, reptiles. From a geological perspective, it did not take long for mammals, some flightless birds grew larger than humans. These species are referred to as terror birds, and were formidable predators. Mammals came to occupy almost every available niche, and some also grew very large, the Earths climate had begun a drying and cooling trend, culminating in the glaciations of the Pleistocene Epoch, and partially offset by the Paleocene-Eocene Thermal Maximum. The continents also began looking roughly familiar at this time and moved into their current positions. The Cenozoic is divided into three periods, the Paleogene, Neogene, and Quaternary, and seven epochs, the Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene. The common use of epochs during the Cenozoic helps paleontologists better organize, there is also more detailed knowledge of this era than any other because of the relatively young, well-preserved rocks associated with it. The Paleogene spans from the extinction of dinosaurs,66 million years ago. It features three epochs, the Paleocene, Eocene and Oligocene, the Paleocene ranged from 66 million to 56 million years ago. The Paleocene is a point between the devastation that is the K-T extinction, to the rich jungles environment that is the Early Eocene. The Early Paleocene saw the recovery of the earth, the continents began to take their modern shape, but all the continents and subcontinent India were separated from each other. Afro-Eurasia was separated by the Tethys Sea, and the Americas were separated by the strait of Panama and this epoch featured a general warming trend, with jungles eventually reaching the poles. The oceans were dominated by sharks as the large reptiles that had once ruled became extinct, archaic mammals filled the world such as creodonts and early primates that evolved during the Mesozoic, and as a result, there was nothing over 10 kilograms. The Eocene Epoch ranged from 56 million years to 33.9 million years ago, in the Early-Eocene, life was small and lived in cramped jungles, much like the Paleocene. There was nothing over the weight of 10 kilograms, among them were early primates, whales and horses along with many other early forms of mammals
32.
Sinkhole
–
A sinkhole, also known as a cenote, sink, sink-hole, shakehole, swallet, swallow hole, or doline, is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes—for example, the dissolution of carbonate rocks or suffosion processes. Sinkholes vary in size from 1 to 600 m both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms, sinkholes may form gradually or suddenly, and are found worldwide. Sinkholes may capture surface drainage from running or standing water, but may form in high. Sinkholes that capture drainage can hold it in limestone caves. These caves may drain into tributaries of larger rivers, the formation of sinkholes involves natural processes of erosion or gradual removal of slightly soluble bedrock by percolating water, the collapse of a cave roof, or a lowering of the water table. Sinkholes often form through the process of suffosion, for example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void. Occasionally a sinkhole may exhibit a visible opening into a cave below, sinkholes also occur in sandstone and quartzite terrains. As the rock dissolves, spaces and caverns develop underground and these sinkholes can be dramatic, because the surface land usually stays intact until there is not enough support. Then, a collapse of the land surface can occur. Sinkholes also form from human activity, such as the collapse of abandoned mines and salt cavern storage in salt domes in places like Louisiana, Mississippi, more commonly, sinkholes occur in urban areas due to water main breaks or sewer collapses when old pipes give way. They can also occur from the overpumping and extraction of groundwater, sinkholes can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Sinkholes tend to occur in karst landscapes, karst landscapes can have up to thousands of sinkholes within a small area, giving the landscape a pock-marked appearance. These sinkholes drain all the water, so there are only subterranean rivers in these areas, examples of karst landscapes with a plethora of massive sinkholes include Khammouan Mountains and Mamo Plateau. The largest known sinkholes formed in sandstone are Sima Humboldt and Sima Martel in Venezuela, some sinkholes form in thick layers of homogenous limestone. On the contact of limestone and insoluble rock below it, powerful underground rivers may form, in such conditions, the largest known sinkholes of the world have formed, like the 662-metre deep Xiaozhai Tiankeng, giant sótanos in Querétaro and San Luis Potosí states in Mexico and others. The state of Florida in the United States is known for having frequent sinkhole collapses, the Murge area in southern Italy also has numerous sinkholes. Sinkholes can be formed in retention ponds from large amounts of rain, an analysis of a case of sinkhole formation under a retention pond due to a large amount of rain can be seen in a sinkhole collapse study
33.
Tectonic uplift
–
Tectonic uplift is the portion of the total geologic uplift of the mean Earth surface that is not attributable to an isostatic response to unloading. One should also take into consideration the effects of denudation, within the scope of this topic, uplift relates to denudation in that denudation brings buried rocks closer to the surface. This process can redistribute large loads from a region to a topographically lower area as well – thus promoting isostatic response in the region of denudation. The timing, magnitude, and rate of denudation can be estimated using pressure-temperature studies, crustal thickening has an upward component of motion and often occurs when continental crust is thrust onto continental crust. The process of nappe stacking can only continue for so long, although the raised surfaces of mountain ranges mainly result from crustal thickening, there are other forces at play that are responsible for tectonic activity. All tectonic processes are driven by force when density differences are present. A good example of this would be the large-scale circulation of the Earths mantle, lateral density variations near the surface also drive plate motion. The dynamics of mountain ranges are governed by differences in the potential energy of entire columns of lithosphere. The highest rates of working against gravity are required when the thickness of the crust changes, lithosphere on the oceanward side of an oceanic trench at a subduction zone will curve upwards due to the elastic properties of the Earths crust. Orogenic uplift is the result of collisions and results in mountain ranges or a more modest uplift over a large region. Perhaps the most extreme form of uplift is a continental-continental crustal collision. In this process, two continents are sutured together and large mountain ranges are produced, the collision of the Indian and Eurasian plates is a good example of the extent to which orogenic uplift can reach. Heavy thrust faulting and folding are responsible for the suturing together of the two plates, the collision of the Indian and Eurasian plates not only produced the Himalaya, but is also responsible for crustal thickening north into Siberia. The Pamir Mountains, Tian Shan, Altai, Hindu Kush, deformation of continental lithosphere can take place in several possible modes. The Ozark Plateau is an uplifted area which resulted from the Permian Ouachita Orogeny to the south in the states of Arkansas, Oklahoma. Another related uplift is the Llano Uplift in Texas, a location named after its uplift features. The Colorado Plateau which includes the Grand Canyon is also the result of tectonic uplift followed by river erosion. The removal of mass from a region will be compensated by crustal rebound
34.
Geology of the Himalaya
–
The geology of the Himalaya is a record of the most dramatic and visible creations of modern plate tectonic forces. This immense mountain range was formed by forces and sculpted by weathering. The Himalaya-Tibet region supplies fresh water for more than one-fifth of the world population and this last feature earned the Himalaya its name, originating from the Sanskrit for the abode of the snow. Numerous granitic intrusions dated at around 500 Ma are also attributed to this event, in the Early Carboniferous, an early stage of rifting developed between the Indian continent and the Cimmerian Superterranes. During the Early Permian, this developed into the Neotethys ocean. From that time on, the Cimmerian Superterranes drifted away from Gondwana towards the north, nowadays, Iran, Afghanistan and Tibet are partly made up of these terranes. In the Norian, a major rifting episode split Gondwana in two parts, the Indian continent became part of East Gondwana, together with Australia and Antarctica. However, the separation of East and West Gondwana, together with the formation of oceanic crust, occurred later, the Indian plate then broke off from Australia and Antarctica in the Early Cretaceous with the opening of the South Indian Ocean. The change of the speed between the Indian and Asian plates from very fast to fast at about 55 Ma is circumstantial support for collision then. The first mechanism also calls upon the subduction of the Indian continental crust below Tibet, second is the extrusion or escape tectonics mechanism which sees the Indian plate as an indenter that squeezed the Indochina block out of its way. The ongoing active collision of the Indian and Eurasian continental plates challenges one hypothesis for plate motion which relies on subduction, one of the most striking aspects of the Himalayan orogen is the lateral continuity of its major tectonic elements. The Himalaya is classically divided into four units that can be followed for more than 2400 km along the belt. The sub-Himalaya, It forms the foothills of the Himalayan Range and is composed of Miocene to Pleistocene molassic sediments derived from the erosion of the Himalaya. These molasse deposits, known as the Muree and Siwaliks Formations, are folded and imbricated. The Lesser Himalaya is mainly formed by Upper Proterozoic to lower Cambrian detrital sediments from the passive Indian margin intercalated with some granites and these sediments are thrust over the Subhimalaya along the Main Boundary Thrust. The Lesser Himalaya often appears in tectonic windows within the High Himalaya Crystalline Sequence, the Central Himalayan Domain, or High Himalaya, forms the backbone of the Himalayan orogen and encompasses the areas with the highest topographic relief. It is commonly separated into four zones, although most of the metasediments forming the HHCS are of late Proterozoic to early Cambrian age, much younger metasediments can also be found in several areas. It is now accepted that the metasediments of the HHCS represent the metamorphic equivalents of the sedimentary series forming the base of the overlying Tethys Himalaya
35.
Show cave
–
Unlike wild caves, they typically possess such features as constructed trails, guided tours, lighting, and regular opening hours. Show cave has inconsistent usage between nations, with many tending to call all caves which are open to the public show caves. However there are caves which are not developed but are visited by very many people. This kind of cave is called a semi-wild cave. Access may involve anything between an easy stroll and dangerous climbing, most cave accidents happen in this kind of cave, as visitors often underestimate the difficulties and dangers. The oldest known cave in the world is Postojna Cave in Slovenia. In 1649 the first authorized cave guide started guiding Baumannshöhle in the Harz in Germany -, the development of electric lighting enabled the illumination of show caves. Early experiments with light in caves were carried out by Lieutenant Edward Cracknel in 1880 at Chifley Cave, Jenolan Caves. In 1881 Sloupsko-Šošůvské Jeskyně, Czech Republic, became the first cave in the world with electric arc light and this light did not use light bulbs, but electric arc lamps with carbon electrodes, which burned down and had to be replaced after some time. The first cave in the world with electric light bulbs as we know today was the Kraushöhle in Austria in 1883. But the light was abandoned after only seven years and the cave is visited with carbide lamps. In 1884 two more caves were equipped with light, Postojna Cave, Slovenia, and Olgahöhle
36.
Seven-Star Cave
–
Seven-Star Cave is an extensive limestone cave complex in Seven-Star Park, both of which are popular tourist attractions in the city of Guilin in Guangxi Autonomous Region in China. The park and caves name derive from the fact the main karst limestone peaks roughly resemble the stars of the Big Dipper constellation, the earliest exploration of Seven-Star Cave dates back to the Tang Dynasty, about 1,300 years ago. The cave has a temperature of about 20 Celsius. The maximum ceiling height inside is 27 metres, and the width is 49 metres. A concrete and stone tour path of approximately 1,000 metres runs through the cave between its entrance and exit points, artificial lighting for walkways and displays is staged throughout, including colored accents, and various formations have names such as A Natural Fresco and The Chessboard. During the Japanese invasion of China in World War II, Guilin residents took refuge in the cave complex, the tour cannot easily be walked independently of groups, since the lights inside the cave are closed behind the groups as they walk away. Signs are posted in both Chinese and English and takes typically 30–60 minutes, like most parks in Guilin, the cave complex maintains an entrance fee, costing 30 RMB beyond the basic park entrance fee of 75 RMB. Seven Stars Park How caves are formed at Guilin
37.
Reed Flute Cave
–
The Reed Flute Cave is a landmark and tourist attraction in Guilin, Guangxi, China. It is a limestone cave with multicolored lighting and has been one of Guilin’s most interesting attractions for over 1200 years. It is over 180 million years old, the cave got its name from the type of reed growing outside, which can be made into flutes. Reed Flute Cave is filled with a number of stalactites, stalagmites. Inside, there are more than 70 inscriptions written in ink and these aged inscriptions tell us that it has been an attraction in Guilin since ancient times. It was rediscovered in the 1940s by a group of fleeing the Japanese troops. Nowadays, multicolored lighting artificially illuminates the cave
38.
Cave
–
A cave is a hollow place in the ground, specifically a natural underground space large enough for a human to enter. Caves form naturally by the weathering of rock and often extend deep underground, the word cave can also refer to much smaller openings such as sea caves, rock shelters, and grottos. A cavern is a type of cave, naturally formed in soluble rock with the ability to grow speleothems. Speleology is the science of exploration and study of all aspects of caves, visiting or exploring caves for recreation may be called caving, potholing, or spelunking. The formation and development of caves is known as speleogenesis, which can occur over the course of millions of years, caves are formed by various geologic processes and can be variable sizes. These may involve a combination of processes, erosion from water, tectonic forces, microorganisms, pressure. Isotopic dating techniques can be applied to cave sediments, in order to determine the timescale when geologic events may have occurred to help form and it is estimated that the maximum depth of a cave cannot be more than 3,000 metres due to the pressure of overlying rocks. For karst caves the maximum depth is determined on the basis of the limit of karst forming processes. Most caves are formed in limestone by dissolution, solutional caves or karst caves are the most frequently occurring caves and such caves form in rock that is soluble. Most occur in limestone, but they can form in other rocks including chalk, dolomite, marble, salt. Rock is dissolved by acid in groundwater that seeps through bedding planes, faults, joints. Over geological epochs cracks expand to become caves and cave systems, the largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3, the dissolution process produces a distinctive landform known as karst, characterized by sinkholes and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation and these include flowstones, stalactites, stalagmites, helictites, soda straws and columns. These secondary mineral deposits in caves are called speleothems, the portions of a solutional cave that are below the water table or the local level of the groundwater will be flooded. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed to be examples of type of solutional cave. They were formed by H2S gas rising from below, where reservoirs of oil give off sulfurous fumes and this gas mixes with ground water and forms H2SO4. The acid then dissolves the limestone from below, rather than from above, caves formed at the same time as the surrounding rock are called primary caves
39.
Stalactite
–
A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material which is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, Stalactites may be composed of amberat, lava, minerals, mud, peat, pitch, sand, and sinter. A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves, the corresponding formation on the floor of the cave is known as a stalagmite. The most common stalactites are speleothems, which occur in limestone caves and they form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the form of calcium carbonate rock which is dissolved by water that contains carbon dioxide. When the solution comes into contact with air the chemical reaction that created it is reversed, the reversed reaction is, Ca 2 → CaCO3 + H 2O + CO2 An average growth rate is 0.13 mm a year. The quickest growing stalactites are formed by a constant supply of slow dripping water rich in calcium carbonate and carbon dioxide. The drip rate must be enough to allow the CO2 to degas from the solution into the cave atmosphere. Too fast a drip rate and the solution, still carrying most of the CaCO3, falls to the floor where degassing occurs. All limestone stalactites begin with a single drop of water. When the drop falls, it deposits the thinnest ring of calcite, each subsequent drop that forms and falls deposits another calcite ring. Eventually, these form a very narrow, hollow tube commonly known as a soda straw stalactite. Soda straws can grow long, but are very fragile. If they become plugged by debris, water flowing over the outside, depositing more calcite. The same water drops that fall from the tip of a stalactite deposit more calcite on the floor below, unlike stalactites, stalagmites never start out as hollow soda straws. Given enough time, these formations can meet and fuse to create pillars of calcium carbonate known as a column, another type of stalactite is formed in lava tubes while lava is still active inside. The mechanism of formation is similar to that of limestone stalactites, a key difference with lava stalactites is that once the lava has ceased flowing, so too will the stalactites cease to grow. This means that if the stalactite were to be broken it would never grow back, the generic term lavacicle has been applied to lava stalactites and stalagmites indiscriminately and evolved from the word icicle
40.
Stalagmite
–
A stalagmite is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites may be composed of amberat, lava, minerals, mud, peat, pitch, sand, the corresponding formation hanging down from the ceiling of a cave is a stalactite. Mnemonics have been developed for which word refers to type of formation, one is that stalactite has a C for ceiling. The most common stalagmites are speleothems, which form in limestone caves. This stalagmite formation occurs only under certain pH conditions within the underground cavern and they form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the form of calcium carbonate rock, which is dissolved by water that contains carbon dioxide. If stalactites – the ceiling formations – grow long enough to connect with stalagmites on the floor, oils and dirt from human contact can also stain the formation and change its color permanently. Another type of stalagmite is formed in lava tubes while lava is still active inside, the mechanism of formation is similar to that of limestone stalagmites. A key difference with lava stalagmites is that once the lava has ceased flowing and this means if the stalagmite were to be broken it would never grow back. Stalagmites in lava tubes are rarer than their stalactite counterparts because during formation the dripping material falls onto still-moving lava floors that absorb or carry the material away, the generic term lavacicle has been applied to lava stalactites and stalagmites indiscriminately, and evolved from the word icicle. A common stalagmite found seasonally or year round in many caves is the ice stalagmite, commonly referred to as icicles, water seepage from the surface will penetrate into a cave and if temperatures are below freezing temperature, the water will collect on the floor into stalagmites. Deposition may also directly from the freezing of water vapor. Similar to lava stalagmites, ice stalagmites form very quickly within hours or days, unlike lava stalagmites however, they may grow back as long as water and temperatures are suitable. Ice stalagmites are more common than their stalactite counterparts because warmer air rises to the ceilings of caves, ice stalactites may also form corresponding stalagmites below them, and given time, may grow together to form an ice column. Stalactites and stalagmites can also form on concrete ceilings and floors, calcium carbonate deposition as a stalagmite occurs when the solution carries the calcium laden leachate solution to the ground under the concrete structure. Carbon dioxide is absorbed into the alkaline solution, which facilitates the chemical reactions to deposit calcium carbonate as a stalagmite. These stalagmites rarely grow taller than a few centimetres, secondary deposits, which create stalagmites, stalactites, flowstone etc, outside the natural cave environment, are referred to as “calthemites”. These concrete derived secondary deposits can’t be referred to as “speleothems” due to the definition of the word, the largest known stalagmite in the world exceeds 70 metres in height and is located in Sơn Đoòng Cave, Vietnam
41.
Elephant Trunk Hill
–
This page is for the landmark in Guilin, China. For the similarly named hill and provincial park in British Columbia, Canada, the Elephant Trunk Hill is a hill, landmark and tourist attraction in Guilin, Guangxi, China. Elephant Trunk Hill is the symbol of the city of Guilin and it got its name because it looks like an elephant drinking water. Elephant Trunk Hill and Water-Moon Cave are located at the confluence of the Taohua River, moon Hill, in Yangshuo County Torghatten, in Norway Elephant Trunk Hill Travel China Guide
42.
Renminbi
–
The renminbi /ˌrɛnmɪnˈbiː/ is the official currency of the Peoples Republic of China. The yuan is the unit of the renminbi, but is also used to refer to the Chinese currency in general. The distinction between the terms renminbi and yuan is similar to that between sterling and pound, which refer to the British currency and its primary unit. One yuan is subdivided into 10 jiao, and a jiao in turn is subdivided into 10 fen, the ISO code for renminbi is CNY, or also CNH when traded in off-shore markets such as Hong Kong. The currency is often abbreviated RMB, or indicated by the yuan sign ¥, in Chinese texts the currency may also be indicated with the Chinese character for the yuan, 圆. The renminbi is legal tender in mainland China, but not in Hong Kong or Macau, renminbi is sometimes accepted in Hong Kong and Macau, and are easily exchanged in the two territories, with banks in Hong Kong allowing people to maintain accounts in RMB. The currency is issued by the Peoples Bank of China, the authority of China. Until 2005, the value of the renminbi was pegged to the US dollar and it has previously been claimed that the renminbis official exchange rate was undervalued by as much as 37. 5% against its purchasing power parity. Since 2006, the exchange rate has been allowed to float in a narrow margin around a fixed base rate determined with reference to a basket of world currencies. The Chinese government has announced that it gradually increase the flexibility of the exchange rate. As a result of the rapid internationalization of the renminbi, it became the worlds 8th most traded currency in 2013, and 5th in 2015. On 1 October 2016, the RMB became the first emerging market currency to be included in the IMFs special drawing rights basket, a variety of currencies circulated in China during the Republic of China era, most of which were denominated in the unit yuán. Each was distinguished by a name, such as the fabi, the gold yuan. During the era of the economy, the value of the renminbi was set to unrealistic values in exchange with western currency. The unrealistic levels at which exchange rates were pegged led to a black market in currency transactions. In the late 1980s and early 1990s, China worked to make the RMB more convertible, through the use of swap centres, the exchange rate was brought to realistic levels and the dual track currency system was abolished. As of 2013, the renminbi is convertible on current accounts, the ultimate goal has been to make the RMB fully convertible. From 1949 until the late 1970s, the state fixed Chinas exchange rate at a highly overvalued level as part of the countrys import -substitution strategy
.svg)
_-_China-7696.jpg)
Geographic data related to Li River at OpenStreetMap
Geographic data related to 
