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CONTINENT (from Lat. continere, "to h...

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Originally appearing in Volume V07, Page 30 of the 1911 Encyclopedia Britannica.
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CONTINENT (from See also:Lat. continere, "to hold together "; hence " connected," " continuous ")  , a word used in See also:physical See also:geography of the larger continuous masses of See also:land in contrast to the See also:great oceans, and as distinct from the submerged tracts where only the higher parts appear above the See also:sea, and from islands generally . On looking at a See also:map of the See also:world, continents appear generally as See also:wedge-shaped tracts pointing southward, while the oceans have a polygonal shape . Eurasia is in some sense an exception, but all the See also:southern terminations of the continents advance into the sea in the See also:form of a wedge—See also:South See also:America, South See also:Africa, See also:Arabia, See also:India, Malaysia and See also:Australia connected by a submarine See also:platform with See also:Tasmania . It is difficult not to believe that these remarkable characters have some relation to the structure of the great globe-See also:mass, and according to T . C . Chamberlin and R . D . See also:Salisbury, in their See also:Geology (1906), " the true conception is perhaps that the ocean basins and See also:continental platforms are but the See also:surface forms of great segments of the See also:lithosphere, all of which See also:crowd towards the centre, the stronger and heavier—the ocean basins—taking See also:precedence and squeezing the weaker and lighter ones—the continents—between them." " The See also:area of the most depressed, or See also:master segments, is almost exactly twice that of the protruding or squeezed ones . This estimate includes in the latter about To,000,000 sq. m. now covered with shallow See also:water . The See also:volume of the See also:hydrosphere is a little too great for the true basins, and it runs over, covering the See also:borders of the continents" (see CONTINENTAL SHELF) . Several theories have been advanced to See also:account for the roughly triangular shape of the continents, but that. presenting the least difficulty is the one expressed above, "since in a spherical surface divided into larger and smaller segments the See also:major See also:part should be polygonal,while the See also:minor residual segments are more likely to be triangular." As bearing on this See also:geological See also:idea, it is interesting to See also:notice in this connexion that the areas of volcanic activity are mostly where See also:continent and ocean meet; and that around the continents there is an almost continuous " deep" from Too to 300 M. broad, of which the Challenger Deep (11,400 ft.) and the great See also:Tuscarora Deep are fragments . If on a map of the world a broad inked See also:brush be swept seawards See also:round Africa, passing into the Mediterranean, round See also:North and South America, round India, then continuously south of See also:Java and round Australia south of Tasmania and northward to the tropic, this broad See also:band will represent the encircling ribbon-like " deep," which gives strength to the See also:suggestion that the continents in their See also:main features are permanent forms and that their structural connexion with the oceans is not temporary and accidental .

The great protruding or " squeezed " segments are the See also:

Eurasian (with an area roughly of twenty-four, reckoning in millions of square See also:miles), strongly ridged on the south and See also:east, and relatively See also:flat on the north-See also:west; the See also:African (twelve), rather strongly ridged on the east, less abruptly on the west and north; the North See also:American (ten), strongly ridged on the west, more gently on the east, and relatively flat on the north and in the interior; the South American (nine), strongly ridged on the west and somewhat on the north-east and south-east, leaving ten for the smaller blocks . The sum of these will represent one-third of the See also:earth's surface, while the remaining two-thirds is covered by the ocean . The See also:foundation structure of the continents is everywhere similar . Their resulting rocks and soils are due to See also:differential minor movements in the past, by which deposits of varying See also:character were produced . These movements, taking See also:place periodically and followed by See also:long periods of See also:rest, produce continued stability for the development and See also:migration of forms of See also:life, the grading of See also:rivers, the development of varied characteristic land forms, the migration and See also:settlement of human beings, the facility or difficulty of intelligent intercourse between races and communities, with finally the commercial interchange of those commodities produced by varying See also:climatic conditions upon different parts of the continental surface; in See also:short, for those See also:geographical factors which form the See also:chief product of past and See also:present human See also:history .

End of Article: CONTINENT (from Lat. continere, "to hold together "; hence " connected," " continuous ")
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