|
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface and the processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentinite
Serpentinite is a metamorphic rock composed predominantly of serpentine group minerals formed by serpentinization of mafic or ultramafic rocks. The ancient origin of the name is uncertain; it may be from the similarity of its texture or color to snake skin. Greek pharmacologist Pedanius Dioscorides, Dioscorides (AD 50) recommended this rock to prevent snakebite. Serpentinite has been called ''serpentine'' or ''serpentine rock'', particularly in older geological texts and in wider cultural settings.California Government Code § 425.2; ''see'' Most of the chemical reactions necessary to synthesize acetyl-CoA, essential to basic biochemical pathways of life, take place during serpentinization. Serpentinite thermal vents are therefore considered a candidate for the origin of life on Earth. Formation and mineralogy Serpentinite is formed by near to complete serpentinization of mafic or ultramafic rocks. Serpentinite is formed from mafic rock that is mineral hydration, hydrate ... [...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 ... [...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] |
Progress In Physical Geography
''Progress in Physical Geography'' is a peer-reviewed academic journal that publishes papers in the fields of Geosciences, multidisciplinary and physical geography. The journal's editors are Nicholas Clifford (King's College London) and George Malanson (University of Iowa). It has been in publication since 1977 and is currently published by SAGE Publications. Scope ''Progress In Physical Geography'' is an international, interdisciplinary journal which publishes papers that focus on developments and debates within Physical Geography. The bi-monthly published journal which is edited by Nicholas Clifford and George Malanson also covers interrelated fields across the Earth, Biological and Ecological System Sciences. Abstracting and indexing '' Progress in Physical Geography'' is abstracted and indexed in, among other databases: SCOPUS, and the Social Sciences Citation Index. According to the ''Journal Citation Reports'', its 2016 impact factor The impact factor (IF) or jour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets are bigger than ice shelf, ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery. Although the surface is cold, the base of an ice sheet is generally warmer due to Geothermal activity, geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams. Even stable ice sheets are continually in motion as the ice gradually flows outward from the central plateau, which is the tallest point of the ice sheet, and towards the margins. The ice sheet slope is low around the plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scandinavia
Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also refer to the Scandinavian Peninsula (which excludes Denmark but includes a part of northern Finland). In English usage, Scandinavia is sometimes used as a synonym for Nordic countries. Iceland and the Faroe Islands are sometimes included in Scandinavia for their Ethnolinguistics, ethnolinguistic relations with Sweden, Norway and Denmark. While Finland differs from other Nordic countries in this respect, some authors call it Scandinavian due to its economic and cultural similarities. The geography of the region is varied, from the Norwegian fjords in the west and Scandinavian mountains covering parts of Norway and Sweden, to the low and flat areas of Denmark in the south, as well as archipelagos and lakes in the east. Most of the population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landform
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geomorphology
Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated 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 comprise the action of water, wind, ice, wildfire, and lif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomorph
In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form (crystal system), resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another due to alteration, or chemical substitution, dissolution and refilling, structural changes or incrustation. The name literally means "false form". Terminology for pseudomorphs is "''replacer'' after ''original''", as in ''brookite'' after ''rutile''. The term ''pseudomorphoses'' was initially used by Haüy. Substitution pseudomorph A substitution pseudomorph is a pseudomorph in which one mineral or other material is replaced by another. The original shape of the mineral remains unchanged, but chemical composition, color, hardness, and other properties change to those of the replacing mineral. This happens typically when a mineral of one composition changes by chemical reaction to another of similar composition, retaining t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentinization
Serpentinization is a hydration and Metamorphic rock, metamorphic transformation of ferromagnesian minerals, such as olivine and pyroxene, in mafic and ultramafic rock to produce serpentinite. Minerals formed by serpentinization include the Serpentine subgroup, serpentine group minerals (antigorite, lizardite, chrysotile), brucite, talc, Ni-Fe alloys, and magnetite. The mineral alteration is particularly important at the sea floor at plate tectonics, tectonic plate boundaries. Formation and petrology Serpentinization is a form of low-temperature (0 to ~600 °C) metamorphism of ferromagnesian minerals in mafic and ultramafic rocks, such as dunite, harzburgite, or lherzolite. These are rocks low in silica and composed mostly of olivine (), pyroxene (), and chromite (approximately ). Serpentinization is driven largely by Mineral hydration, hydration and oxidation of olivine and pyroxene to serpentine subgroup, serpentine group minerals (antigorite, lizardite, and chrysotile), bru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
