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Pneumatolytic
Pneumatolysis is an obsolete geologic term for magma emitting gasses that alter surrounding rock or crystallize minerals. Pneumatolysis is now considered a type of hydrothermal interaction. See also * Metasomatism Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in the chemical com ... References Further reading * Philip Lake and R. H. Rastall. ''A textbook of geology'' (1920). 3rd ed. Edward Arnold: Londonpp. 251-255 describes pneumatolysis, especially in granites. * ''McGraw-Hill Encyclopedia of the Geological Sciences.'' Second edition. New York: McGraw-Hill, 1987. p. 518 External links * Igneous petrology Metamorphic petrology Obsolete geology theories Geological processes {{geological-process-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasing temperature and pressure characterize ''retrograde metamorphism''. Metamorphic petrology is the study of metamorphism. Metamorphic petrologist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasomatism
Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in the chemical composition, excluding volatile components. It is the replacement of one rock by another of different mineralogical and chemical composition. The minerals which compose the rocks are dissolved and new mineral formations are deposited in their place. Dissolution and deposition occur simultaneously and the rock remains solid. Synonyms of the word ''metasomatism'' are metasomatosis and metasomatic process. The word ''metasomatose'' can be used as a name for specific varieties of metasomatism (for example '' Mg-metasomatose'' and '' Na-metasomatose''). Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism produces skarns, greisen, and may affect hornfel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Lake
Philip Lake (9 April 1865, Morpeth, Northumberland – 12 June 1949, Cambridge, England) was a British geologist and palaeontologist. Education After graduating from Morpeth Grammar School (where his father was the headmaster), Philip Lake studied from 1881 to 1884 at the Durham College of Science, where he learned geology from G. A. L. Lebour. In 1884 Lake matriculated at St John's College, Cambridge. There he graduated with a B.A. in 1887. Career Soon after receiving his B.A, he joined the Geological Survey of India. In 1890 his monograph ''The Geology of South Malabar, Between the Beypore and Ponnani River'' was published and he resigned from the Geology Survey due to ill health. From 1890 to 1892 he studied at the University of Cambridge, where he graduated with an M.A. For a number of years Lake held no academic appointment and earned money from private tutoring, examining, and lecturing. In 1903 he became headmaster at the Colchester Technical School. In the department of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Petrology
Igneous petrology is the study of igneous rocks—those that are formed from magma. As a branch of geology, igneous petrology is closely related to volcanology, tectonophysics, and petrology in general. The modern study of igneous rocks uses a number of techniques, some of them developed in the fields of chemistry, physics, or other earth sciences. Petrography, crystallography, and isotopic studies are common methods used in igneous petrology. Methods Determination of chemical composition The composition of igneous rocks and minerals can be determined via a variety of methods of varying ease, cost, and complexity. The simplest method is observation of hand samples with the naked eye and/or with a hand lens. This can be used to gauge the general mineralogical composition of the rock, which gives an insight into the composition. A more precise but still relatively inexpensive way to identify minerals (and thereby the bulk chemical composition of the rock) with a petrographic mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Petrology
Petrology () is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because both make heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Modern sedimentary petrology is making increasing use of chemistry. Background Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through and drawn on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsolete Geology Theories
Obsolescence is the process of becoming antiquated, out of date, old-fashioned, no longer in general use, or no longer useful, or the condition of being in such a state. When used in a biological sense, it means imperfect or rudimentary when compared with the corresponding part of other organisms. The international standard IEC 62402:2019 Obsolescence Management defines obsolescence as the "transition from available to unavailable from the manufacturer in accordance with the original specification". Obsolescence frequently occurs because a replacement has become available that has, in sum, more advantages compared to the disadvantages incurred by maintaining or repairing the original. Obsolete also refers to something that is already disused or discarded, or antiquated. Typically, obsolescence is preceded by a gradual decline in popularity. Consequences Driven by rapid technological changes, new components are developed and launched on the market with increasing speed. The resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
