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Etchplain
An etchplain is a plain where the bedrock has been subject to considerable "etching" or subsurface weathering. Etchplanation is the process forming etchplains. Contrary to what the name might suggest, etchplains are seldom completely flat and usually display some relief, as weathering of the bedrock does not advance uniformly. This means that weathering is unrelated to the flatness which might be derivative of various other processes of planation including peneplanation and pediplanation. Erosion of etchplains can result in the exposure of inselbergs such as bornhardt and tors. Generally the topography exposed at a stripped etchplain, that is an etch surface, after erosion of regolith is one with many irregularities as result of structurally defined areas of rock strength. A distinction can be made between etchplains and etch surfaces as the latter may or may not be flat and can represent the landform arising from the stripping of an etchplain. As climate changes, arid and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inselberg
An inselberg or monadnock () is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain. In Southern Africa a similar formation of granite is known as a koppie, an Afrikaans word ("little head") from the Dutch diminutive word ''kopje''. If the inselberg is dome-shaped and formed from granite or gneiss, it can also be called a bornhardt, though not all bornhardts are inselbergs. An inselberg results when a body of rock resistant to erosion, such as granite, occurring within a body of softer rocks, is exposed by differential erosion and lowering of the surrounding landscape. Etymology Inselberg The word ''inselberg'' is a loan word from German, and means "island mountain". The term was coined in 1900 by geologist Wilhelm Bornhardt (1864–1946) to describe the abundance of such features found in eastern Africa. At that time, the term applied only to arid landscape features. However, it has sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planation Surface
In geology and geomorphology a planation surface is a large-scale surface that is almost flat with the possible exception of some residual hills. The processes that form planation surfaces are labelled collectively planation and are exogenic (chiefly erosion). Planation surfaces are planated regardless of bedrock structures. On Earth, they constitute some of the most common landscapes. Geological maps indicate that planation surfaces may comprise 65% of the landscapes on Saturn's largest moon, Titan, which hosts a hydrological cycle of liquid methane. Peneplains and pediplains are types of planation surfaces planated respectively by "peneplanation" and "pediplanation". In addition to these there are planation surfaces proposed to be formed by cryoplanation, marine processes, areal glacial erosion and salt weathering. The term ''planation surface'' is often preferred over others because some more specific planation surface types and processes remain controversial. Etchplains are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julius Büdel
Julius Büdel (8 August 1903 – 28 August 1983) was a German geomorphologist noted for his work on the influence of climate in shaping landscapes and landforms. In his work Büdel stressed the importance of inherited landforms in present-day landscapes and argued that many landforms are the result of a combination of processes, and not of a single process. Büdel estimated that 95% of mid-latitude landforms are relict. Büdel studied both cold-climate processes in Svalbard and "tropical" weathering processes in India to understand the origin of the relief of Central Europe, which he argued was a palimpsest of landforms formed at different times and under different climates. For Central Europe Büdel concluded that in Late Cretaceous to Early Pliocene times etchplains formed. Then in Late Pliocene to Early Pleistocene times a transition period occurred in landscape forming processes. Finally in the Late Pleistocene periglaciation and deep permafrost made Central Europe a place o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Surface
The African Surface or African Erosion Surface is a land surface formed by erosion covering large swathes of Africa.Burke & Gunnell 2008, pp. 6–7. The type area of the surface lies in South Africa where the surface was first identified as such by Lester Charles King in the mid-20th century.Burke & Gunnell 2008, pp. 13–14. The term was coined by King for certain high surfaces in southern Africa. Over the years he redefined it various times leaving some confusion not on its reality but on the matter of its precise meaning and extent.Burke & Gunnell 2008, pp. 15-16. In 2008 the term was redefined as a composite surface. According to the 2008 study the African Surface is made up by etchplains formed between 70 and 40 million years ago. In this sense the existence of parts of the African Surface at different elevations is the result of continental-scale warping due to endogenic forces. In Central Africa the African Surface can be found in uplifted position in several domes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedrock
In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bedrock is often called an outcrop. The various kinds of broken and weathered rock material, such as soil and subsoil, that may overlie the bedrock are known as regolith. Engineering geology The surface of the bedrock beneath the soil cover (regolith) is also known as ''rockhead'' in engineering geology, and its identification by digging, drilling or geophysics, geophysical methods is an important task in most civil engineering projects. Superficial deposition (geology), deposits can be very thick, such that the bedrock lies hundreds of meters below the surface. Weathering of bedrock Exposed bedrock experiences weathering, which may be physical or chemical, and which alters the structure of the rock to leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Weathering processes are divided into ''physical'' and ''chemical weathering''. Physical weathering involves the breakdown of rocks and soils through the mechanical effects of heat, water, ice, or other agents. Chemical weathering involves the chemical reaction of water, atmospheric gases, and biologically produced chemicals with rocks and soils. Water is the principal agent behind both physical and chemical weathering, though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important. Chemical weathering by biological action is also known as biological wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropics
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to as the tropical zone and the torrid zone (see geographical zone). In terms of climate, the tropics receive sunlight that is more direct than the rest of Earth and are generally hotter and wetter as they aren't affected as much by the solar seasons. The word "tropical" sometimes refers to this sort of climate in the zone rather than to the geographical zone itself. The tropical zone includes deserts and snow-capped mountains, which are not tropical in the climatic sense. The tropics are distinguished from the other climatic and biomatic regions of Earth, which are the middle latitudes and the polar regions on either side of the equatorial zone. The tropics constitute 40% of Earth's surface area and contain 36% of Earth's landmass. , the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landscape
A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or man-made features, often considered in terms of their aesthetic appeal.''New Oxford American Dictionary''. A landscape includes the physical elements of geophysically defined landforms such as (ice-capped) mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use, buildings, and structures, and transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence, often created over millennia, landscapes reflect a living synthesis of people and place that is vital to local and national identity. The character of a landscape helps define the self-image of the people who inhabit it and a sense of place that differentiates one region from other regions. It is the dyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bailey Willis
Bailey Willis (March 31, 1857 in Idle Wild-on-Hudson, New York, United States – February 19, 1949 in Palo Alto, California) was a geological engineer who worked for the United States Geological Survey (USGS), and lectured at two prominent American universities. He also played a key role in getting Mount Rainier designated as a national park in 1899. After later focusing more on seismology, he became one of the world's leading earthquake experts of his time. Early life and family Bailey Willis was born March 31, 1857, the son of poet and publisher Nathaniel Parker Willis and Cornelia Grinnell Willis. His brother was Grinnell Willis. His father died when he was only ten years old. At the age of thirteen he was taken to England and Germany for four years of schooling, and thus acquired fluency in German at a time when many scientific texts were only available in that language. He entered Columbia University and in five years completed his studies with the degrees of mechanical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward James Wayland
Edward is an English given name. It is derived from the Anglo-Saxon name ''Ēadweard'', composed of the elements '' ēad'' "wealth, fortune; prosperous" and '' weard'' "guardian, protector”. History The name Edward was very popular in Anglo-Saxon England, but the rule of the Norman and Plantagenet dynasties had effectively ended its use amongst the upper classes. The popularity of the name was revived when Henry III named his firstborn son, the future Edward I, as part of his efforts to promote a cult around Edward the Confessor, for whom Henry had a deep admiration. Variant forms The name has been adopted in the Iberian peninsula since the 15th century, due to Edward, King of Portugal, whose mother was English. The Spanish/Portuguese forms of the name are Eduardo and Duarte. Other variant forms include French Édouard, Italian Edoardo and Odoardo, German, Dutch, Czech and Romanian Eduard and Scandinavian Edvard. Short forms include Ed, Eddy, Eddie, Ted, Teddy and Ned. Peo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical Omani Empire and colonial territories of the British East Africa Protectorate and German East Africa, the term ''East Africa'' is often (especially in the English language) used to specifically refer to the area now comprising the three countries of Kenya, Tanzania, and Uganda. However, this has never been the convention in many other languages, where the term generally had a wider, strictly geographic context and therefore typically included Djibouti, Eritrea, Ethiopia, and Somalia.Somaliland is not included in the United Nations geoscheme, as it is internationally recognized as a part of Somalia. *Tanzania, Kenya, Uganda, Rwanda, Burundi, Democratic Republic of Congo and South Sudan are members of the East African Community. The firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
