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Granofels
Granofels is a term referring to medium- to coarse-grained metamorphic rocks which have a ''granoblastic'' texture (having poorly formed, equi-granular crystal grains visible to the naked eye) and lack distinct foliation or lineation. The granofels term encompasses rocks which are known under more specific names, such as marble or hornfels Hornfels is the group name for a set of contact metamorphic rocks that have been baked and hardened by the heat of intrusive igneous masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable. These pro .... References Metamorphic rocks {{petrology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and distorti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granoblastic
Granoblastic is an adjective describing an anhedral phaneritic equi-granular metamorphic rock texture. Granoblastic texture is typical of quartzite, marble, charnockites and other non-foliated metamorphic rocks without porphyroblasts. Characteristics defining granoblastic texture include: grains visible to the unaided eye, sutured boundaries and approximately equidimensional grains. The grain boundaries intersect at 120° triple junctions under ideal conditions. Variation from the ideal results from stress produced foliation during crystallization resulting in schistose textures. A rock that has a granoblastic texture can be termed a ''granofels Granofels is a term referring to medium- to coarse-grained metamorphic rocks which have a ''granoblastic'' texture (having poorly formed, equi-granular crystal grains visible to the naked eye) and lack distinct foliation or lineation. The granofels ...''. ReferencesDictionary of Mining, Mineral, and Related Terms [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or Dolomite (mineral), dolomite. Marble is typically not Foliation (geology), foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphosed limestone, but its use in stonemasonry more broadly encompasses unmetamorphosed limestone. Marble is commonly used for Marble sculpture, sculpture and as a building material. Etymology The word "marble" derives from the Ancient Greek (), from (), "crystalline rock, shining stone", perhaps from the verb (), "to flash, sparkle, gleam"; Robert S. P. Beekes, R. S. P. Beekes has suggested that a "Pre-Greek origin is probable". This Stem (linguistics), stem is also the ancestor of the English language, English word "marmoreal," meaning "marble-like." While the English term "marble" resembles the French language, French , most other European languages (with words like "marmoreal") more closely resemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hornfels
Hornfels is the group name for a set of contact metamorphic rocks that have been baked and hardened by the heat of intrusive igneous masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable. These properties are due to fine grained non-aligned crystals with platy or prismatic habits, characteristic of metamorphism at high temperature but without accompanying deformation. The term is derived from the German word ''Hornfels'', meaning "hornstone", because of its exceptional toughness and texture both reminiscent of animal horns. These rocks were referred to by miners in northern England as whetstones. Most hornfels are fine-grained, and while the original rocks (such as sandstone, shale, slate and limestone) may have been more or less fissile owing to the presence of bedding or cleavage planes, this structure is effaced or rendered inoperative in the hornfels. Though many hornfels show vestiges of the original bedding, they break acro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Geological Survey
The British Geological Survey (BGS) is a partly publicly funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS headquarters are in Keyworth, Nottinghamshire, England. Its other centres are located in Edinburgh, Wallingford, Cardiff and London. The current motto of the BGS is: ''Gateway to the Earth''. History and previous names The Geological Survey was founded in 1835 by the Board of Ordnance as the Ordnance Geological Survey, under Henry De la Beche. This was the world's first national geological survey. It remained a branch of the Ordnance Survey for many years. In 1965, it was merged with the Geological Museum and Overseas Geological Surveys, under the name of Institute of Geological Sciences. On 1 January 1984, the institute was renamed the British Geological Survey (and often referred to as the BGS), a name still carried today. Competenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
