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Bornhardt
A bornhardt () is a dome-shaped, steep-sided, bald rock outcropping at least in height and several hundred metres in width. They are named after Wilhelm Bornhardt (1864–1946), a German geologist and explorer of German East Africa, who first described the feature. While ''bornhardt'' was originally used to sometimes denote a type of inselberg (literally island mountain—an isolated dome in an otherwise flat landscape), the term ''bornhardt'' is used in modern literature to refer to domed hills and mountains regardless of isolation; thus, not all bornhardts are inselbergs and not all inselbergs are bornhardts. Bornhardts are commonly composed of igneous rocks, often granites, but examples of gneiss, quartzite and arkose bornhardts exist. The Sugarloaf Mountain of Rio de Janeiro is a typical example of this landform and is the origin of the common bornhardt nickname "sugar loaf". Bornhardts are most easily seen in arid and semi-arid regions, but occur over a wide range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Wilhelm Conrad Eduard Bornhardt
Friedrich Wilhelm Conrad Eduard Bornhardt (20 April 1864 Braunschweig - 2 December 1946 Goslar) was a German geologist, engineer and explorer, and was Director of the Berlin College of Mines (Bergakademie) from 1907 to 1916. He explored and set out the groundwork of the geology of German East Africa. His published work consisted of two parts – an account of his travels and his geological findings. In 1896 he set out from Lindi to Lake Malawi where he stayed for ten months undertaking eight exploratory trips of the region. Afterwards he returned to the coast to write up his geology journals. In 1897 he explored the protectorate of Dar es Salaam as far as the Ruvuma Region, the Zanzibar Archipelago and the Usambara Mountains, carrying out some thirteen journeys. In all he covered about and prepared maps of the geology and vegetation of the regions he traversed. Bornhardt documented the existence of coal reserves in present-day Tanzania in 1896 when he explored the Songwe Kiwira are ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nubbin (landform)
In geomorphology a nubbin is a small and gentle hill consisting of a bedrock core dotted with rounded residual blocks. The blocks derive from disintegrated and weathered bedrock layers. In particular it is assumed that the boulders of the nubbins are the remnants of the outer one or two exfoliation shells that weathered underground - albeit some weathering can continue to occur once the boulders are exposed on surface. Nubbins form in a similar way to castle koppies and bornhardts, and the three landforms can be seen as different expressions of the same phenomena. Nubbins occur often in patterned groups. Nubbins can be found in humid tropical- and monsoon-climate areas. According to geomorphologist C. R. Twidale this is the environment where most nubbins form. Nubbins outside the humid or seasonally-humid tropics are relict landforms formed in a humid and tropical past or form in areas of high subsurface humidity. Examples of localities with nubbins include the Southwester ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climatic Geomorphology
Climatic geomorphology is the study of the role of climate in shaping landforms and the earth-surface processes. An approach used in climatic geomorphology is to study relict landforms to infer ancient climates. Being often concerned about past climates climatic geomorphology considered sometimes to be an aspect of historical geology. Since landscape features in one region might have evolved under climates different from those of the present, studying climatically disparate regions might help understand present-day landscapes. For example, Julius Büdel studied both cold-climate processes in Svalbard and weathering processes in tropical 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. Sub-disciplines The various subbranches of climatic geomorphology focus on specific climatic environments. Desert geomorphology Desert geomorphology or the geomorphology of arid an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dike (geology), dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF diagram, QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Everard Ranges
The Everard Ranges, officially known as The Everard Ranges, is a range of low rounded granite hills located in the Australian state of South Australia in the Aṉangu Pitjantjatjara Yankunytjatjara lands about west of Mintabie. It is of Palaeocene origin between 20 and 60 million years ago, in Central Australia . Rising into domes above a Cenozoic peneplain, which is here about above sea level, they were named by Ernest Giles in 1873 after SA Commissioner of Crown Lands William Everard, and consist of monoliths or bornhardts, rich in caves and overhangs with Aboriginal rock painting galleries. The ranges are similar to Uluru and Kata Tjuta. Giles described them in his book, ''Australia Twice Traversed'' as follows: ''"Arriving at the first hills of the Everard, I found they were all very peculiar, bare, red, granite mounds, being the most extraordinary ranges one could possibly imagine, if indeed any one could imagine such a scene. They have thousands of acre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamiesberge
The Kamiesberg or Kamiesberge is a mountain range of jumbled granite inselbergs or bornhardts dotted over sandy plains and centered on Kamieskroon in Namaqualand in South Africa. This range is very like the Matopos of Zimbabwe in appearance. It stretches for about 140 km (60 mi) from Garies in the south to Springbok in the north and forms a plateau between the Sandveld of the Cape West Coast and Bushmanland in the east, with the Hardveld of the mountainous central Kamiesberg escarpment in the midst. History The region was formerly occupied by Khoekhoe who were nomadic pastoralists. The buildings of Kamieskroon were moved from a previous location known as Bowesdorp, named after the village doctor. Steep granite hills and a shortage of water hindered development, so that it was relocated. The foundations of the original village may still be seen in a rocky ravine some 8 km north of Kamieskroon. The Leliefontein mission station, known for the Leliefontein mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matopos
The Matobo National Park forms the core of the Matobo or Matopos Hills, an area of granite kopjes and wooded valleys commencing some south of Bulawayo, southern Zimbabwe. The hills were formed over 2 billion years ago with granite being forced to the surface; it has eroded to produce smooth "whaleback dwalas" and broken kopjes, strewn with boulders and interspersed with thickets of vegetation. Matopo/Matob was named by the Lozwi. A different tradition states that the first King, Mzilikazi Khumalo when told by the local residents that the great granite domes were called madombo he replied, possible half jest, "We will call them matobo" - an Isindebele play on 'Bald heads'. The Hills cover an area of about , of which is National Park, the remainder being largely communal land and a small proportion of commercial farmland. The park extends along the Thuli, Mtshelele, Maleme and Mpopoma river valleys. Part of the national park is set aside as a game park, which has been stock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugarloaf Mountain
Sugarloaf Mountain (, ) is a peak situated in Rio de Janeiro, Brazil, on a peninsula at the mouth of Guanabara Bay. Rising above the harbor, the peak is named for its resemblance to the traditional shape of concentrated refined loaf sugar. It is known worldwide for its cableway and panoramic views of the city and beyond. The mountain is one of several monolithic granite and quartz mountains that rise straight from the water's edge around Rio de Janeiro. Geologically, it is considered part of a family of steep-sided rock outcroppings known as bornhardts. The mountain is protected by the Sugarloaf Mountain and Urca Hill Natural Monument, created in 2006. This became part of a World Heritage Site declared by UNESCO in 2012. Origins of the name The name Sugarloaf was coined in the 16th century by the Portuguese during the heyday of sugarcane trade in Brazil due to sugar imports from the Portuguese conquest of Goa, according to historian Vieira Fazenda. Blocks of sugar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Geographical Journal
''The Geographical Journal'' is a quarterly peer-reviewed academic journal of the Royal Geographical Society (with the Institute of British Geographers). It publishes papers covering research on all aspects of geography. It also publishes shorter Commentary papers and Review Essays. Since 2001, ''The Geographical Journal'' has been published in collaboration with Wiley-Blackwell. The journal dates back to two related publications established in the 19th century, ''Journal of the Royal Geographical Society of London'' (published from 1831 to 1880), and ''Proceedings of the Royal Geographical Society of London '', published from 1857 to 1877. Then ''Proceedings of the Royal Geographical Society and Monthly Record of Geography'', published from 1879 to 1892, continued and absorbed the previous journals. In 1893, the journal renamed itself ''The Geographical Journal''. Prior to 2000, ''The Geographical Journal'' published society news alongside articles and it continues to publish the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exfoliation Joint
Exfoliation joints or sheet joints are surface-parallel fracture systems in rock, often leading to the erosion of concentric slabs. General characteristics * Commonly follow topography. * Divide the rock into sub-planar slabs. * Joint spacing increases with depth from a few centimeters near the surface to a few meters * Maximum depth of observed occurrence is around 100 meters. * Deeper joints have a larger radius of curvature, which tends to round the corners of the landscape as material is eroded * Fracture mode is tensile * Occur in many different lithologies and climate zones, not unique to glaciated landscapes. * Host rock is generally sparsely jointed, fairly isotropic, and has high compressive strength. * Can have concave and convex upwards curvatures. * Often associated with secondary compressive forms such as arching, buckling, and A-tents (buckled slabs) Formation Despite their common occurrence in many different landscapes, geologists have yet to reach an agr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Australia
Central Australia, also sometimes referred to as the Red Centre, is an inexactly defined region associated with the geographic centre of Australia. In its narrowest sense it describes a region that is limited to the town of Alice Springs and its immediate surrounds including the MacDonnell Ranges. Commonly, it refers to an area up to from Alice Springs, in every direction. In its broadest use it can include almost any region in inland Australia that has remained relatively undeveloped, and in this sense is synonymous with the term Outback. In a modern, more formal sense it can refer to the administrative region used by the Northern Territory government, as of 2022. Centralia is another term associated with the area, most commonly used by locals. Administrative region of the NT Economic region There are six regions in the Northern Territory for the purposes of economic planning, as defined by the Northern Territory Government: * Central Australia * Darwin, Palmersto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
