In geomorphology, badlands are areas of bare ground which have been intensely eroded by running water into a maze of miniature canyons and steep slopes. There may be hundreds of tiny stream channels within a single square kilometre or mile, with the channels containing water only after rainstorms. Common on clays and shales in areas where the climate is semi-arid, they occur also on the tip-heaps of mines, especially of china-clay workings, in areas where the climate is wetter. Resistant layers of rock are often left as cappings on pillars of softer rock; these structures are known as hoodoos, or pedestal rocks. Research Badlands
Mountains are often classified according to their mode of formation: Fold
mountains; Block mountains; Residual mountains; Volcanic mountains.
High mountain chains such as the Himalayas, Andes, Alps, and Rockies are known as new fold mountain systems. The term 'fold' is a reference to the way in which such mountains have been formed. Throughout millions of years slow movements of the earth's crust have caused these
mountains to be raised. The movements which have resulted in mountain buildings were not, however, vertical uplifts. They were primarily horizontal movements, the effect of which was to cause the crust of the earth to 'wrinkle', in a similar way to which a tablecloth wrinkles if it is pushed along the table. The arched or upraised parts of the folds are known as anticlines and the troughs as synclines. These folds can vary greatly in size. Mountain building is undoubtedly due to some deep-seated cause. For a long period the most simple explanation was that folding was entirely due to the cooling and contraction of the earth, so that the crust, already cold and shrunken, had to wrinkle to fit itself to the still cooling and contracting 'core'. One of the objections advanced against this theory is that the amount of shrinking necessary to account for the Himalayas, Alps, etc., seems to be greater than the mere contraction of the earth would allow. While the theory of contraction cannot be completely rejected, serious consideration must be given to the more recent explanations of mountain building. For instance, Wegener suggests that mountain building may be due to the 'wrinkles' produced by the drifting of a continental mass, e.g. that the Alps were formed by the northward drift of the African continent towards the more stable blocks of Central Europe. As the African mass drifted slowly northward the zone between it and the European mass became narrower, and the land was raised into high ridges or folds. The raising of the Alps was accompanied by the formation of the deep trough which contains the Mediterranean Sea. The same hypothesis would account for the building of the Himalayas and the depression of the Indo-Gangetic trough by the northward drift of the Deccan mass.
During the physical history of the earth, mountain building appears to have proceeded more actively at some periods than others. Fold mountains are, therefore, not all of the same age. The newest group of fold mountains include the Himalayas, Alps, Rockies, and Andes. During an earlier period of folding (the Carboniferous) the Pennines, Appalachians, the Cape Ranges of South Africa, and the Dividing Range of Australia were uplifted. A still earlier period of folding accounted for the original mountains of Scotland and Norway, of which the present mountains are merely the worn down stumps. The older fold mountains, which have been subjected to the forces of denudation (such as the weather, rivers, glaciers, etc.) for long geological periods, are much lower and less rugged than the newer fold mountains. The term 'new fold' is applied to the mountain ranges which have been folded most recently, but they seem very old when their age in actual years is considered because they were uplifted many millions of years before historic time. Mountain building is a very long and slow process; and in the case of certain mountain chains, such as the Andes and the mountains of Japan, is probably still proceeding.
The new fold mountain systems of the world, except in such instances as the simple low folds of the Weald (South-east England), usually consist of high parallel ranges, the average height being well over 3000 metres. In the Himalayas' the highest peak rises to 8840 metres; in the Andes 7000 metres; in the Rockies 6000 metres; in the Alps to 4600 metres. Vast though these heights appear, the wrinkles of the earth's crust are only slight. The highest mountain in the world (MountEverest) is about five miles high, so that on a globe of 40 cm, diameter it would protrude only 2.5 mm. Most of the active volcanoes are found in the neighbourhood of fold mountains, where the crust of the earth has been fractured during the process of folding. All around the PacificOcean there are many active and extinct volcanoes, as in New Zealand, the East Indies, Japan, and North, Central, and South America. Another belt of active volcanoes is associated with the fold mountains of the West Indies. The mountains of this type are characterised by ruggedness of relief in contrast to the smooth and rounded contours of mountain areas which have been subjected to weathering agents for long periods of time. This is obvious if pictures of the Alps and the Scottish Highlands are compared.
Mountains are effective climatic barriers, and the climates of regions on either side of a high mountain range are very different. For example, the coast lands of British Columbia have an equable climate and a heavy rainfall, while the lands to the east of the Rockies have an extreme climate and light rainfall. Again, the climate of the mountainous areas differs from that of the adjacent lowlands. The great mountain systems of the world are mainly important for their minerals, and, in the temperate zone, for their lumber. In the plateau regions of some mountain systems agriculture has been made possible by irrigation, and above the forests in temperate areas there are valuable alpine pastures. The swift streams of mountains are frequently sources of hydro-electric power, especially in countries which have no coal, such as Switzerland and Norway. In North America, the Western Cordillera provides gold, copper, lead, and silver, especially in the states of Nevada and Montana. The Andes provide tin and copper (Bolivia), gold and platinum
(Colombia), and silver (Peru). The Highlands of East Australia are important for copper and gold. The lumbering industry is specially important in British Columbia, Washington, and Oregon (soft woods), the Central American mountainous lands (hard woods), the Himalayan slopes (teak and sal), and the Scandinavian mountains (soft woods).
To provide food for the mining communities in inaccessible mountain areas, agriculture has been developed. There are numerous irrigation schemes in operation in most of the mountain states of the USA, e.g. at SaltLake City in Utah. Similarly, the Andean states, e.g. Bolivia, grow small quantities of cereals in the plateau areas. Mountain pastures have been utilised most extensively for cattle rearing in Switzerland and Scandinavia. The vast central plateau of Asia is, owing to difficulty of access and climatic extremes, so isolated from other regions that very little development of any kind, on modern lines, has taken place. High mountain ranges are also barriers to communication, and so tend to separate peoples. Traffic across mountains is limited to the passes, which are often so high as to be snowbound in winter. Such ranges as the Alps, Andes, etc. can only be crossed with great difficulty or by expensive tunnelling.
It sometimes happens that movement of the earth's crust occurs along cracks or faults. Where such movement leaves a block of higher land standing between two areas of lower land, the highland is known as a 'Block Mountain' or horst. The Vosges and Black Forest Mountains are examples of such formations These mountains are usually very steep-sided, and often the summit levels are roughly the same.
When an area of highland remains standing above the general level after rivers and other natural agents have lowered the surface of the surrounding area, the name residual mountain is used. Sometimes such highlands are called 'mountains of denudation'. This term can usually be applied to the mountain ridges associated with 'dissected plateaux'. Included in this class are the mountain ridges of the Highlands of Scotland, the Sierras of Central Spain, and the Mesas and Buttes of the western plateaulands of the United States.
Mountains may be formed by volcanic material piled up around a crater, such mountains are popularly known as volcanoes. Research Mountains
In geography, a zone is any of the five divisions of the surface of the earth characterised by their latitude or temperature differences. From north to south the zones are divided by the Arctic Circle, the tropic of Cancer, the tropic of Capricorn, and the Antarctic Circle. At the polar extremes are the North Frigid Zone (lying north of the Arctic Circle) and the South Frigid Zone (south of the Antarctic Circle). The North Temperate Zone lies between the Arctic Circle and the tropic of Cancer; the South Temperate Zone lies between the Antarctic Circle and the tropic of Capricorn. The Torrid Zone forms a belt on both sides of the equator between the tropic of Cancer and the tropic of Capricorn. This division of zones is a rough representation of the earth's temperature or climatic zones and does not take into account differences in elevation, proximity of oceans, or the movement of air masses. The distribution of climate and biomes is far more complex than these five zones suggest. Research Zone
The British Shorthair is an old and rather ordinary breed of shorthaired cat descended from the mating of Roman domestic cats with feral and wild cats in Britain. The body is broad-shouldered, muscular and powerful. The chest is full and broad, the legs short and strong, the back level and the paws well-rounded and firm. the short tail is thick at the base and tapers to a rounded tip. the head is broad and round on a short, solid neck. The breed is robust and healthy, developing in the changeable British climate, and occurs in many colours, black, white, tabby, cream and others. Research British Shorthair
The castor oil plant (Ricinus communis) or castor bean is a highly poisonous variable herb, shrub or tree (depending upon climate) of the family Euphorbiaceae, native to India and tropical Africa. It has large, reddish coloured leaves which are long-stalked, alternate and palmate with coarsely toothed segments. Terminating the stems are panicle-like inflorescences of green monoecious flowers, the stalked female flowers above the male flowers below, both without petals. The fruit is a spiny, greenish capsule with large, oval, shiny, bean-like, highly poisonous seeds with variable brownish mottling on a whitish background. Research Castor Oil Plant
The Green Hairstreak (Callophrys rubi) is a butterfly of the family Lycaenidae found throughout the Palaearctic region where it produces either one or two generations depending upon the climate. The butterflies can be found on dry hillsides rich in blackthorn, in high mountains and in peat- bogs. The caterpillar feeds on a variety of plants including broom, bramble and bilberry. Research Green Hairstreak
Ouranosaurus was a dinosaur of the Cretaceous period. Ouranosaurus was a medium-sized dinosaur, about seven metres long, that walked on its hind legs and was similar in appearance and related to Iguanodon. However, Ouranosaurus had a 'sail' of skin that ran along the backbone and was supported by spines, one on each vertebra. Remains of Ouranosaurus have been found in North Africa and from sediments found with the remains we know the climate Ouranosaurus lived in was warm and dry. Research Ouranosaurus
Serpentes is the snake suborder of reptiles, containing some 2700 species found throughout the moderate and tropical climate zones in all manner of biotopes. Research Serpentes
The welsh onion, salad onion or spring onion (Allium pistulosum) is a Siberian perennial plant very hardy in the British climate. Its roots instead of bulbing as in the common onion, are long and tapering and its stems and leaves are hollow. It is cultivated for its young growths used to flavour salads in the spring. Research Welsh Onion
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Badlands
