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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 Southwestern United S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devil's Marbles
Karlu Karlu / Devils Marbles Conservation Reserve is a protected area in the Northern Territory of Australia located in the locality of Warumungu about south of Tennant Creek, and north of Alice Springs. The nearest settlement is the small town of Wauchope located to the south. The Devils Marbles are of great cultural and spiritual significance to the Aboriginal traditional owners of the land, and the reserve protects one of the oldest religious sites in the world as well as the natural rock formations found there. ''Karlu Karlu'' is the local Aboriginal term for both the rock features and the surrounding area. The Aboriginal term translates as "round boulders" and refers to the large boulders found mainly in the western side of the reserve. The English name for the boulders derives from a quote by John Ross during the 1870 Australian Overland Telegraph Line expedition, where he said "This is the Devil’s country; he’s even emptied his bag of marbles around the place!" T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Rowland Twidale
Charles Rowland Twidale is an Australian geomorphologist active at the University of Adelaide. Twidale's research has covered varied subjects including structural geomorphology, weathering, ancient landscapes in shield regions, granite landforms in deserts, paleosurfaces and the history of geomorphology. Twidale has been most active investigating the geomorphology of Australia and Spain. In 1976 C. R. Twidale was president of the Royal Society of South Australia. In 1993 he was awarded the Mueller Medal by the Australian and New Zealand Association for the Advancement of Science The Australian and New Zealand Association for the Advancement of Science (ANZAAS) is an organisation that was founded in 1888 as the Australasian Association for the Advancement of Science to promote science. It was modelled on the British As ....ANZAAS > Mueller Medal Recipientsarchive.is Retrieved 9 July 2017, References External links * Australian geomorphologists Historians of scie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion Landforms
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion proceed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomorphology
Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform and terrain history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology, and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field. Overview Earth's surface is modified by a combination of surface processes that shape landscapes, and geologic processes that cause tectonic uplift and subsidence, and shape the coastal geography. Surface processes co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869-1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli-tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namaqualand
Namaqualand (khoekhoe: "Nama-kwa" meaning Nama Khoe people's land) is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of . It is divided by the lower course of the Orange River into two portions – Little Namaqualand to the south and Great Namaqualand to the north. Little Namaqualand is within the Namakwa District Municipality, forming part of Northern Cape Province, South Africa. It is geographically the largest district in the country, spanning over 26,836 km2. A typical municipality is Kamiesberg Local Municipality. The semidesert Succulent Karoo region experiences hot summers, sparse rainfall, and cold winters.Discover South Africa: Your Online Travel Directory. Discover Namakwa. Great Namaqualand in the Karas Region of Namibia, is sparsely populated by the Namaqua, a Khoikhoi people who have traditionally inhabited the Namaqualand region. Tourism The area’s landscape ranges from an unexploited coast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacDonnell Ranges
The MacDonnell Ranges, or Tjoritja in Arrernte, is a mountain range located in southern Northern Territory. MacDonnell Ranges is also the name given to an interim Australian bioregion broadly encompassing the mountain range, with an area of .IBRA Version 6.1 data The range is a long series of mountains in central , consisting of parallel ridges running to the east and west of . The mountain range contains many spectacular gaps and gorges as well as areas of A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southwestern United States
The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Nevada, Oklahoma, Texas, and Utah. The largest cities by metropolitan area are Phoenix, Las Vegas, El Paso, Albuquerque, and Tucson. Prior to 1848, in the historical region of Santa Fe de Nuevo México as well as parts of Alta California and Coahuila y Tejas, settlement was almost non-existent outside of Nuevo México's Pueblos and Spanish or Mexican municipalities. Much of the area had been a part of New Spain and Mexico until the United States acquired the area through the Treaty of Guadalupe Hidalgo in 1848 and the smaller Gadsden Purchase in 1854. While the region's boundaries are not officially defined, there have been attempts to do so. One such definition is from the Mojave Desert in California in the west (117° west longitude) t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relict (geology)
A relict, in geology, is a structure or mineral from a parent rock that did not undergo metamorphic change when the surrounding rock did, or a rock that survived a destructive geologic process. Some geologic processes are destructive or transformative of structures or minerals, and when a process is not complete or does not completely destroy certain features, the left-over feature is a relict of what was there before. For example, relict permafrost is an area of ancient permafrost which remains despite a change in climate which would prohibit new permafrost from forming or it could be a fragment of ancient soil or sediment found in a younger stratum. A relict sediment is an area of ancient sediment which remains unburied despite changes in the surrounding environment. In pedology, the study of soil formation and classification, ancient soil found in the geologic record is called a paleosol, material formed in the distant past on what was then the surface. A relict paleosol is stil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monsoon Climate
An area of tropical monsoon climate (occasionally known as a sub-equatorial, tropical wet climate or a tropical monsoon and trade-wind littoral climate) is a tropical climate sub-type that corresponds to the Köppen climate classification category ''Am''. Tropical monsoon climates have monthly mean temperatures above in every month of the year and a dry season. The tropical monsoon climate is the intermediate climate between the wet Af (or tropical rainforest climate) and the drier Aw (or tropical savanna climate). A tropical monsoon climate's driest month has on average less than 60 mm, but more than 100-\left(\frac\right). This is in direct contrast to a tropical savanna climate, whose driest month has less than 60 mm of precipitation and also less than 100-\left(\frac\right) of average monthly precipitation. In essence, a tropical monsoon climate tends to either have more rainfall than a tropical savanna climate or have less pronounced dry seasons. A tropical monsoon c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomorphology
Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform and terrain history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology, and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field. Overview Earth's surface is modified by a combination of surface processes that shape landscapes, and geologic processes that cause tectonic uplift and subsidence, and shape the coastal geography. Surface processes co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Climate
Tropical climate is the first of the five major climate groups in the Köppen climate classification identified with the letter A. Tropical climates are defined by a monthly average temperature of 18 °C (64.4 °F) or higher in the coolest month, and feature hot temperatures all year-round. Annual precipitation is often abundant in tropical climates, and shows a seasonal rhythm but may have seasonal dryness to varying degrees. There are normally only two seasons in tropical climates, a wet (rainy / monsoon) season and a dry season. The annual temperature range in tropical climates is normally very small. Sunlight is intense in these climates. There are three basic types of tropical climates within the tropical climate group: tropical rainforest climate (Af), tropical monsoon climate (Am) and tropical wet and dry climate or tropical savannah (Aw for dry winters, and As for dry summers), which are classified and distinguished by the precipitation and the precipitation lev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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