Indochina(redirected from Mainland Southeast Asia)
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Indochina,Fr. Indochine, former federation of states, SE Asia. It comprised the French colony of Cochin ChinaCochin China
, Fr. Cochinchine, historic region (c.26,500 sq mi/68,600 sq km) of Vietnam, SE Asia. The capital and chief city was Saigon (now Ho Chi Minh City). Cochin China was bounded by Cambodia on the northwest and north, by the historic region of Annam on the
..... Click the link for more information. and the French protectorates of TonkinTonkin
, historic region (c.40,000 sq mi/103,600 sq km), SE Asia, now forming the heartland of N Vietnam. The capital was Hanoi. Tonkin was bordered on the north by China, on the east by the Gulf of Tonkin, on the south by the historic region of Annam, and on the S and W by Laos.
..... Click the link for more information. , AnnamAnnam
, historic region (c.58,000 sq mi/150,200 sq km) and former state, in central Vietnam, SE Asia. The capital was Hue. The region extended nearly 800 mi (1,290 km) along the South China Sea between Tonkin on the north and Cochin China on the south.
..... Click the link for more information. , LaosLaos
, officially Lao People's Democratic Republic, republic (2005 est. pop. 6,217,000), 91,428 sq mi (236,800 sq km), SE Asia. A landlocked nation, Laos is bordered by China on the north, by Vietnam on the east, by Cambodia on the south, and by Thailand and Myanmar on the west.
..... Click the link for more information. , and CambodiaCambodia
, Khmer Kampuchea, officially Kingdom of Cambodia, constitutional monarchy (2005 est. pop. 13,607,000), 69,898 sq mi (181,035 sq km), SE Asia. Cambodia is bordered by Thailand on the west and north, by Laos on the north, by Vietnam on the east, and by the Gulf of
..... Click the link for more information. (Cochin China, Tonkin, and Annam were later united to form VietnamVietnam
, officially Socialist Republic of Vietnam, republic (2005 est. pop. 83,536,000), 128,400 sq mi (332,642 sq km), Southeast Asia. Occupying the eastern coastline of the Southeast Asian peninsula, Vietnam is bounded by China on the north, by Laos and Cambodia on the west,
..... Click the link for more information. ). The capital was HanoiHanoi
, city (1997 est. pop. 3,500,800), capital of Vietnam, on the right bank of the Red River. It is the transportation hub of the country, with two airports and rail connections to Kunming, China, as well as to the main Chinese system centering on Beijing; it is also linked
..... Click the link for more information. . The federation formed the easternmost region of the Indochinese peninsula (which it shared with Myanmar, Thailand, and Malaya) and faced E on the South China Sea. The cultures of Indochina were influenced by China and India. The centuries before European intervention saw the growth and decline of the Khmer EmpireKhmer Empire
, ancient kingdom of SE Asia. In the 6th cent. the Cambodians, or Khmers, established an empire roughly corresponding to modern Cambodia and Laos. Divided during the 8th cent., it was reunited under the rule of Jayavarman II in the early 9th cent.
..... Click the link for more information. in Cambodia, the rise and fall of ChampaChampa
, the kingdom of the Chams, which flourished in Vietnam from the 2d cent. A.D. until the 17th cent. At its greatest extent it occupied Annam as far north as central Vietnam. Its culture was strongly affected by Hindu influences.
..... Click the link for more information. , and the steady expansion of Annam. European penetration began in the 16th cent.; in the 19th-century race for a colonial empire, the French took (1862, 1867) Cochin China as a colony and gained protectorates over Cambodia (1863), Annam (1884), and Tonkin (1884). In 1887 they formed those four states into a union of Indochina, with a governor-general at its head; Laos was added to the union in 1893. In World War II, France was forced to accept Japanese intervention in N Indochina in 1940; the subsequent Japanese move into S Indochina (July, 1941) was viewed by the United States as a threat to the Philippines; it prompted the freezing of all Japanese assets in the United States and precipitated the diplomatic exchanges cut short by the Japanese attack on Pearl Harbor. Even before the end of the war, the French announced plans for a federation of Indochina within the French Union, with greater self-government for the various states. The federation was accepted in Cambodia and Laos. Vietnamese nationalists, however, demanded (1945) the complete independence of Annam, Tonkin, and Cochin China as Vietnam, and after Dec., 1946, these regions were plunged into bitter fighting between the French and the extreme nationalists, oftentimes led by Communists. The war in Vietnam dragged on for years, culminating in the French defeat at DienbienphuDienbienphu
or Dien Bien Phu
, former French military base, N Vietnam, near the Laos border. It was the scene in 1954 of the last great battle between the French and the Viet Minh forces of Ho Chi Minh in Indochina. The French occupied the base by parachute drop in Nov.
..... Click the link for more information. . The Geneva ConferenceGeneva Conference,
any of various international meetings held at Geneva, Switzerland. Some of the more important ones are discussed here. 1 International conference held Apr.–July, 1954, to restore peace in Korea and Indochina.
..... Click the link for more information. in 1954 effectively ended French control of Indochina.
a peninsula in Southeast Asia. It is bounded by the Bay of Bengal, the Andaman Sea, and the Strait of Malacca to the west and by the South China Sea and its gulfs, the most important of which are the Gulf of Siam and the Gulf of Bac Bo (Tonkin), to the east. Its arbitrary northern border runs in a straight line from the delta of the Ganges and Brahmaputra rivers to the delta of the Hong River. The peninsula has an area of about 2 million sq km. Thailand, Cambodia, and most of Burma, Malaysia, Laos, and Vietnam, as well as a small part of the state of Bangladesh, are located in Indochina. The eastern shores are weakly indented; in the west there are many small bays, peninsulas, and offshore islands (for example, Moscos Islands and the Mergui Archipelago).
Terrain. Three major mountain systems—the Arakan Mountains (Yakhaing), the Tenasserim Range (Tanao Si), and the Annamite Cordillera (Truong Son)—stretch from north to south. They are separated by broad lowlands and plains (the Irrawaddy Plain, the Chao Phraya Valley [also called the Mae Nam Valley or Menam Valley], and the Cambodian Plain), plateaus (Korat), and uplands (the Shan Upland and others). The highest elevations are in the northwest (Mount Victoria, 3,053 m); the rest of the peninsula is dominated by mid-mountain and low-mountain terrain. The Arakan Mountains, situated in western Indochina, consist of parallel ranges of medium height, separated by deep erosion-tectonic valleys. The mountains of the central and eastern parts of Indochina have smoother terrain with stepped slopes, brought about by fault tectonics. The Shan Upland is characterized by flat water divides dissected by deep valleys. Karst is widespread. The lowlands are composed primarily of alluvial deposits, as well as lacustrine deposits, sometimes (mainly in Burma) complicated by low mountain ranges and isolated remnants.
Geological structure and mineral resources. Most of Indochina is occupied by Paleozoic and Mesozoic folded systems and the Indochinese Central Massif, which the systems encompass from west to east; the smaller western part (central and western Burma, Bangladesh) belongs to a region of Cenozoic folded structure. The central and southeastern parts of the peninsula are occupied by the Indochinese Central Massif, which consists of a number of blocks divided by fractures. Precambrian formations of the base have been found in the eastern block. Most of the massif is covered by shallow Paleozoic and Mesozoic continental and maritime deposits of the mantle. From the west (the Burmese-Malaysian zone) and the northeast (the northern Vietnamese zone), the massif is framed by plicate structures. The late Precambrian, Paleozoic, and Triassic rocks of the Burmese-Malaysian zone are characterized by a uniform terrigenous-carbonate composition. The Paleozoic and Lower Mesozoic formations of the northern Vietnamese zone are environmentally differentiated. Intensive tectonic movements accompanied by granitoid magmatism occurred here in the Middle Carboniferous period. The Hercynian structures created by these movements are revealed on the periphery of the Indochinese Massif. Upper Paleozoic and Triassic layers of maritime and continental deposits lie unconformably on them. In the late Triassic and early Jurassic the geosynclinal development was completed by up-thrusts and the intrusion of granites; the formation of Jurassic and Cretaceous continental depressions began at this time. Outpourings of effusive rock (mainly basalt) occurred and the Mekong, Chao Phraya, Hanoi, and other deposited depressions, filled to great depths with alluvium, were formed during the Cenozoic period.
A zone of Cenozoic folded structure lies to the west of the system of Paleozoic and early Mesozoic folds in central and western Burma. It includes the Irrawaddy and cis-Arakan down-warps and the anticline of the Arakan Mountains, which divides them. The downwarps are filled with weakly dislocated Cenozoic deposits. The anticline is composed of deformed Mesozoic effusive-sedimentary strata, and intrusions of hyperbasic rocks and diorites are known.
There are large deposits of petroleum in the Paleocene and Neocene deposits of both downwarps in the Cenozoic folded region. Indochina has the world’s largest tin and tungsten deposits (in the southern part of eastern Burma and in western Thailand and Malaysia); they are associated with a band of Jurassic granites that stretches for almost 3,000 km. There are considerable reserves of lead and zinc, deposits of which—like those of copper—are associated with late Paleozoic and Triassic granitoids (Burma and Laos). Deposits of nickel (Burma) and bauxites (Malaysia) are concentrated in the crusts of weathering. There are numerous deposits of various types of iron ores. The northern part of Burma has old ruby and sapphire mines. There are also small deposits of gold. Coal deposits are found in Meso-zoic-Cenozoic sediments. The Democratic Republic of Vietnam has a varied and abundant supply of several minerals.
Climate. Most of Indochina has a subequatorial climate; south of 10° N lat., it is equatorial. Seasonal variations in temperature and precipitation, as well as monsoon circulation of air masses, are noted under subequatorial climatic conditions. In the lowlands the average January temperature ranges from 20° to 26°C; the average April temperature (the hottest month) ranges from 30° to 31 °C, and the average July temperature is 27°-29°C. In the mountains the temperature goes down to 15°C in January and up to 24°-25°C in July. In northern Indochina frosts and snowfalls occur in places near the crest of mountain ranges. Most of the precipitation is brought in by the southwest summer monsoons; hence the most precipitation (2,500-5,000 mm annually) falls on the western coast and on the western, windward slopes of the mountains. In the interior plains total annual precipitation decreases to 1,300-2,200 mm, and in places (for example, in a number of regions in Burma), less than 1,000 mm. On the eastern coast of Indochina, because of the influence of the northeastern monsoon, the annual precipitation again increases (to more than 2,000 mm in places), but the maximum shifts to late summer and fall. In the intermontane hollows of central Indochina and on the slopes of the adjacent mountains there is a clearly marked arid winter season. Constant high temperatures (in the plains, 25°-28°C; in the mountains, 18°-21°C), as well as considerable precipitation (2,500-3,000 mm annually), are characteristic of regions of equatorial climate.
Rivers and lakes. The river network is dense, and most of the rivers have a great deal of water. Seasonal variations in their levels are noted, with a sharp increase in summer under the influence of the monsoon rains. The largest rivers—the Mekong, Salween, and Irrawaddy—originate on the Tibetan Plateau; they have extensive basins and are characteristically fed by snow and rain. In their upper reaches the rivers flow through narrow, deep canyons, and there are rapids. The middle and especially lower courses are calm; the rivers are primarily of the plains type, with broad deltas forming at their mouths and moving seaward with each passing year. Other rivers, including the large Chao Phraya River are fed by rain. Lakes are numerous, of tectonic or relict origin (remnants of maritime gulfs), but few are large (Tonle Sap in Cambodia and Inle in Burma).
Types of landscapes. In the most moist mountainous regions of western Indochina, evergreen tropical forests have grown up with a very complex species composition, with a predominance of Dipterocarpaceae, palms, fig trees, bamboo, and woody ferns on lateritic and reddish brown wood soils. There are mangrove forests in places along the seacoasts and in the river deltas. Deciduous tropical forests of varied composition and sclerophyl-lous evergreen forests and shrubs growing on reddish brown wood soils predominate in the mountains of interior regions of Indochina. In the north at elevations of 700-800 m, tropical species give way to subtropical and boreal species (evergreen oak, chestnut, and pine); in the south the boundary of their incidence extends to higher elevations. The lateritic and reddish-brown soils of the savannas, among the sclerophyllous herbage of which rise isolated low trees and shrubs, are predominant on the plains and in enclosed hollows. The fauna is diverse. Forest animals are predominant; most characteristic are the apes (gibbons and macaques) and Lemuroidea, as well as the Indian elephant, tiger, rhinoceros, panther, Asiatic black bear, wildcat, wild boar, porcupine, and Russian flying squirrel. Birds are also abundant, including the bird of paradise, parrot, peacock, pheasant, and red jungle fowl; herons, storks, and flamingos live in the river deltas. Among the amphibians, crocodiles are widespread. There are many snakes, some of which are poisonous.
REFERENCESVitvitskii, G. N. Klimaty zarubezhnoi Azii. Moscow, 1960.
Geologiia lugo- Vostochnoi Azii: Indokitai. Leningrad, 1969.
Kurakova, L. I. Birma: Prirodnye raiony i landshafty. Moscow, 1967.
Pendleton, R. L. Geografiia Tailanda. Moscow, 1966. (Translated from English.)
Fridland, V. M. Priroda Severnogo V’etnama. Moscow, 1961.
Shcheglova, T. N. V’etnam. Moscow, 1957.
N. V. AlEKSANDROVSKAlA, N. M. KAZAKOVA, and E. S. POSTF’NIKOV