Unreferenced date January 2007 Country rock is a Geology geological term meaning the rock native to an area. It is similar and in many cases interchangeable with the terms basement geology basement and wall rock s. The term is used to denote the usual strata of a region in relation to the rock which is being discussed or observed. The following are areas in geology when the term country rock is used Intrusive settings when describing a intrusion pluton or dike geology dike one may describe the igneous rock as intruding the surrounding country rock , the rock into which the pluton has intruded. In describing the texture or structure of lit par lit intrusion, the intrusive is described in relation to the country rock or wall rock Alluvial settings when describing recent alluvium the material that has arrived through volcano volcanic , glacier glacial or river fluvial action can be described as a veneer on the country rock Category igneous rocks Category Petrology Petrology stub ja ... more details
. Explanations A fold geology folded rock strata cut by a thrust fault B large intrusion cutting through ... geology volcanic dyke cutting through A, B & C E even younger rock strata overlying C & D F normal ... and sedimentary, metamorphic, and igneous rock Main RockgeologyRock cycle There are three major types of rock igneous, sedimentary, and metamorphic. The rock cycle is an important concept in geology ... content of the rock and give it a characteristic fabric geology fabric . The sedimentary rock ... an igneous rock may once again crystallize. The majority of research in geology is associated with the study ... into the Country rockgeology overlying rock . Deposition can occur when sediments settle onto ..., between tectonic plates. When rock units are placed under horizontal compression geology ...Geology2 For the scientific journal Geology journal File WasatchFault.JPG thumb 300px Students examining the Wasatch Fault near Salt Lake City , Utah . Geology from the Ancient Greek Greek , g , earth and , logos , study is the science comprising the study of solid Earth , the rockgeology rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history ... of life , and paleoclimatology past climates . In modern times, geology is commercially important for mining mineral and petroleum geology hydrocarbon exploration and for evaluating water resources ... Geology environmental problems, and for providing insights into past climate change ... Main History of geology Timeline of geology Image Geological map Britain William Smith 1815.jpg ... geology ref The study of the physical material of the Earth dates back at least to ancient Greece ... that modern geology began in the Islamic Golden Age medieval Islamic world . ref The Saracens themselves were the originators not only of algebra, chemistry, and geology, but of many of the so ... works included the earliest writings on the geology of India , hypothesizing that the Indian subcontinent ... more details
Unreferenced stub auto yes date December 2009 A succession , in geology, is a group of rock units or stratum strata that succeed one another in chronology chronological order. Rock successions are often easily seen on exposed sections of a geology geological column or wall. Based on uncomfortable or comfortable succession. DEFAULTSORT Succession Geology Category Geochronology Geology stub ... more details
Unreferenced stub auto yes date December 2009 In geology a lens is a body of ore or Rockgeologyrock or a deposit that is thick in the middle and thin at the edges, resembling a convex lens in cross section. Adjective lenticular . A lens can also refer to an irregular shaped formation consisting of a porous , Permeability fluid permeable sedimentary deposit surrounded by impermeable rock. DEFAULTSORT Lens Geology Category Petrology Category Sedimentology Geology stub it Lente geologia pt Lente geologia uk ... more details
Unreferenced date November 2009 A melanosome in geology refers to the dark, mafic mineral bands formed in migmatite which is undergoing eutaxitic melting probably to form granite . These form bands with leucosome s and such a texture may be described as schlieren or migmatitic . See also Metamorphism References http www.whitman.edu geology winter Petrology Ch 2022 20Metamorphic 20Classification.ppt metamorphic rock classification DEFAULTSORT Melanosome Geology Category Petrology geology stub ... more details
Unreferenced stub auto yes date December 2009 A sequence in geology refers to a sequence of geological events, processes, or rocks, arranged in chronology chronological order. A rock stratigraphy stratigraphical sequence is a geography geographical , or lithology lithostratigraphic , discrete unit greater than a Group stratigraphy group or supergroup rank, and traceable over large areas of a continent. A stratigraphic sequence is bounded by Unconformity unconformities of inter region al scope, such as in the division of craton s. DEFAULTSORT Sequence Geology Category Stratigraphy Category Geology terminology Geology stub ... more details
Unreferenced date December 2007 In geology the term compression refers to a set of stresses directed toward the center of a rock mass. Compressive strength refers to the maximum compressive stress that can be applied to a material before failure occurs. When the maximum compressive stress is in a horizontal orientation, thrust fault ing can occur, resulting in the shortening and thickening of that portion of the crust geology crust . When the maximum compressive stress is vertical, a section of rock will often fail in normal fault s, horizontally extending and vertically thinning a given layer of rock. Compressive stresses can also result in fold geology folding of rocks. Because of the large magnitudes of lithostatic stress in tectonic plate s, tectonic scale deformation geology deformation is always subjected to net compressive stress. See also Gravitational compression Category Structural geology Category Geology terminology geology stub ca Compressi mec nica ... more details
by which they are shaped. Geologists typically study rockgeologyrock , sediment , soil , river s, and natural resources . Branches of geologyGeology applies primarily to Earth, but can be applied to any planet. Geology of Earth Subdisciplines of geology Economic geology Mining Mining geology Petroleum geology Engineering geology Environmental geology Geochemistry Geological modelling Geomorphology Geophysics Historical geology Hydrogeology Mineralogy Paleontology Petrology Sedimentology Stratigraphy Structural geology Volcanology Planetary geology Main Planetary geology See also Geology of solar terrestrial planets Geology of Mercury Geology of Venus Geology of the Moon Geology of Mars Jupiter Internal structure Geology of Jupiter Saturn Physical characteristics Geology of Saturn Uranus Physical characteristics Geology of Uranus Neptune Physical characteristics Geology of Neptune Principles of geology Principle of intrusive relationships Principle of cross cutting ...see also Index of geology articles The following outline is provided as an overview of and topical guide to geologyGeology &ndash one of the Earth science s, it is the study of the Earth, with the general exclusion of present day life, flow within the ocean, and the atmosphere. The field of geology ... succession History of geology Main article History of geology Geological history of Earth Timeline of geology General geology concepts Geologic provinces Image World geologic provinces.jpg thumb 300px ... Geologic province s legend f96 Shield geology Shield legend f9c Continental platform Platform legend 9fc Orogeny Orogen legend 9cf Basin geology Basin legend 969 Large igneous rock igneous province legend ff9 Extended crust geology crust border dc8 main Geologic province Geologic provinces based on origin Shield geology Shield Platform geology Platform shield covered with sediment Orogen Island ... Extended Crust geology crust Rifted margin Rift Plate tectonics main Plate tectonics Occupations in Geology ... more details
Greenland is the largest island on Earth . Only one fifth of its surface area is exposed bedrock , the rest being covered by ice . The exposed surface is approximately 410,000 km sup 2 sup . Its geology is dominated by crystalline Rock geology rocks of the Precambrian Shield . ref name geus http www.geus.dk program areas raw materials greenl map greenland gr map anhstart uk.htm Greenland Geology. Geological Survey of Denmark and Greenland . 20 June 2003 retrieved 26 Dec 2010 ref There are large deposits of Rare earth element rare earth oxides at Kvanefjeld . See also Gemstone industry in Greenland Notes reflist Category Geology of Greenland Greenland stub regional geology stub no Gr nlands geologi ... more details
File Tibetan rocky land.JPG thumb 300px Tibet an rocky land, likely a result of combined eduction and erosion . In geology, eduction is a process in which the Earth crust spreads sideways, exposing deep seated rocks. It is prominent in middle layers of the Himalayas , where gravity pushes the mountains down. Together with a high grade of erosion, this activity brings deep rocks to the surface, many from more than a depth of 100 km. The unusually fast elevation preserves rare metastable minerals , e.g. diamonds and coesite . ref http geology.about.com od structureslandforms a tibetanplat.htm The Tibetan Plateau By Andrew Alden, About.com. Retrieved on April 12, 2009 ref See also Desert pavement , describing other forms of surface rock formation. References reflist DEFAULTSORT Eduction Geology Category Geology Category Geology terminology geology stub ... more details
References Reflist See also Rock microstructure Texture geology Orientation tensor DEFAULTSORT Fabric Geology Category Geology de Gef ge Geologie it Fabric geologia nl Maaksel ... of Structural Geology url http books.google.co.uk books?id ycASqdxSG3YC&pg PA52&dq 22shape fabric ... processes. S fabric a planar fabric such as Cleavage geology cleavage or Foliation geology foliation when it forms the dominant fabric in a rock, it may be called an S tectonite . L fabric a linear fabric such as mineral stretching Lineation geology lineation where aggregates of recrystallised grains ... it forms the dominant fabric in a rock, it may be called an L tectonite. Penetrative fabric a fabric that is present throughout the rock, generally down to the Particle size grain size grain scale ... more details
File Muzeum Z ota w Z otoryi fyllit Panenska H rka 21.07.2011 p.jpg thumb right 265px Phyllite showing cleavage Fissility refers to the property of Rock geology rock s to split along planes of weakness into thin sheets. ref http books.google.co.uk books?id voakD8HV9DgC&pg PA92&lpg PA92&dq fissility&source bl&ots b818afMe2r&sig yFStYNTyUSEUSsfdqLBKwiEZNoE&hl en&ei bDm3Su cH9eN4gaGirV8&sa X&oi book result&ct result&resnum 10 v onepage&q fissility&f false Tucker , M.E. 2001. Sedimentary petrology an introduction to the origin of sedimentary rocks, WileyBlackwell, 3rd Edition, 272pp. ref This is commonly observed in shale s, which are sedimentary rock s, and in slate s and phyllite s, which are foliation geology foliated metamorphic rock s. The fissility in these rocks is caused by the preferred alignment of platy phyllosilicate grains due to Compaction geology compaction , deformation or new mineral growth. ref http bulletin.geoscienceworld.org cgi content abstract 64 8 869 Ingram, R.L. 1953. Fissility of mudrocks, GSA Bulletin, 64, 869 878. ref A highly fissile rock splits easily along the Cleavage geology cleavage . ref Chattanooga Shale The shale is highly fissile easily cleaved most often black but may be brown where weathered. Anderson, Carl 1976 http www.caves.org survey gss GSSWebsite Report Caves files gssrck.pdf Index and Short Description to the Geologic terms used by the GSS Georgia State Base Geologic Map page 5 archived http web.archive.org web 20110703215343 http www.caves.org survey gss GSSWebsite Report Caves files gssrck.pdf here by Internet Archive on 3 July 2011 ref See also Cleavage geology Fabric geology References Reflist DEFAULTSORT Fissility Geology Category Structural geology geology stub ca Fissilitat geologia ... more details
Detritus IPA en d tra t s , adjective detrital , IPA en d tra t l pron is a geological term used to describe particles of Rock geology rock derived from pre existing rock through processes of weathering and erosion . Detrital particles can consist of Lithic Fragment geology lithic fragments particles of recognisable rock , or of monomineralic fragments mineral grains . These particles are often transported through sedimentary processes into depositional systems such as riverbeds, lakes or the ocean forming sedimentary successions. diagenesis Diagenetic processes can transform these sediments into rock through cementation and lithification , forming sedimentary rocks such as sandstone. These rocks can then in turn again be weathered and eroded to form a second generation of sediment. External links http www.isgs.illinois.edu glossary.shtml DETRITUS Illinois State Geological Survey Glossary of Geologic Terms Petrology stub DEFAULTSORT Detritus Geology Category Sedimentology de Detritus Geologie eo Gruzo geologio he nl Detritus geologie ja nn Detritus i geologi ... more details
In geology , the terms basement and crystalline basement are used to define the rocks below a sedimentation sedimentary platform geology platform or cover, or more generally any rock below sedimentary rock s or sedimentary basin s that are metamorphic rock metamorphic or Igneous rock igneous in origin. In the same way the sediment s and or sedimentary rocks on top of the basement can be called a cover or sedimentary cover . Usage In a discussion of Europe an geology, the basement generally refers to rocks older than the Variscan orogeny . Citation needed date September 2009 On top of this older basement Permian evaporite s and Mesozoic limestone s were deposited. The evaporites form a Strength of materials weak zone on which the harder stronger limestone cover was able to move over the hard basement, making the distinction between basement and cover even more pronounced. Citation needed date September 2009 In Andes Andean geology the basement refers to the Proterozoic , Paleozoic and early Mesozoic Triassic to Jurassic rock units as the basement to the late Mesozoic and Cenozoic Andean sequences developed following the onset of subduction along the western margin of the South American Plate . ref Teresa Moreno, et. al., The geology of Chile, Geological Society of London, 2007, Ch. 2 Metamorphic and Igneous Basement Complexes, p. 5, ISBN 978 1862392205 ref When discussing the Trans Mexican Volcanic Belt of Mexico the basement include Proterozoic, Paleozoic and Mesozoic age rocks ... A. Alaniz lvarez and Angel F. Nieto Samaniego, eds., Geology of M xico, Geological Society of America ... in disciplines of geology like Sedimentary basin basin geology , sedimentology and petroleum geology ... See also Craton platform geology Platform Shield geology Shield References Reflist Parker, Sybil P. Ed. . 1997. McGraw Hill Dictionary of Geology and Mineralogy. New York McGraw Hill. Bates, Robert L ... Basement Geology Category Cratons Category Plate tectonics Category Stratigraphy Category Geology ... more details
Otheruses Vergence disambiguation Unreferenced date March 2008 Cleanup date September 2009 In structural geology , the vergence of a Fold geology fold is the direction in which an antiform is inclined or overturned. The term vergence comes from the German language German vergenz , which means overturn . When folds are symmetric in shape, the vergence tells a geologist only where to find the next anticline or syncline . However, in asymmetric folding, where one limb of a fold is longer than the other the vergence will then occur dominantly in the direction in which thrusting took place. If a number of deformation phases can be recognized in a rock, each phase will have its own vergence. However, since each succeeding phase deforms structures and geometries of older phases, the vergence of each of the older phases may be of little use. Geometrically the vergence is the up dip direction of the axial plane of the fold. The axial plane will physically coincide with the axial plane foliation, if folding deformation of the rock is sufficient to cause a foliation. If a Fold geology fold in the bedding is formed in the same deformation phase as the regional foliation, the foliation planes will be oriented parallel to the plane of the fold axes i.e. perpendicular to the principal stress physics stress direction . Therefore, the angle between bedding and foliation is dependent on the rocks position in the fold. The regional foliation is normally the dominant foliation in the rock, and the bedding is the sediment ary layering in the rock. DEFAULTSORT Vergence Geology Category Structural geology tectonics stub de Vergenz Geologie nl Vergentie geologie ... more details
Unreferenced date June 2009 In petroleum geology , the maturity of a Rockgeologyrock is a measure of its state in terms of hydrocarbon generation. Maturity is established using a combination of geochemistry geochemical and basin modelling techniques. Organic rich rocks termed source rock s will alter under increasing temperature such that the organic molecule s slowly mature into hydrocarbon s see diagenesis . Source rocks are therefore broadly categorised as immature no hydrocarbon generation , sub mature limited hydrocarbon generation , mature extensive hydrocarbon generation and overmature most hydrocarbons have been generated . The maturity of a source rock can also be used as an indicator of its hydrocarbon potential . That is, if a rock is sub mature, then it has a much higher potential to generate further hydrocarbons than one that is overmature. See also Van Krevelen diagram References references van Krevelen, D.W. 1950 . Graphical statistical method for the study of structure and reaction processes of coal , Fuel , 29 , 269 84. van Krevelen, D.W. and Schuyer, J. 1957 Coal science . Elsevier publishing company. http books.google.com books?id ztj2aqgh9 4C&pg PA129&dq Van Krevelen diagram&lr &as brr 3&sig ACfU3U1EemKYLWdzkM1Sr3q61ZhTAcsSXg The chemistry and technology of petroleum Category Geochemistry Category Petroleum geologygeology stub ... more details
A cobble is a clastic rocks clast of rockgeologyrock with a particle size of convert 64 mm to convert 256 mm based on the Particle size grain size Krumbein phi scale of sedimentology . Cobbles are generally considered to be larger than pebble s 4 to 64 millimetres diameter and smaller than boulder s greater than 256 millimetres diameter . A rock made predominantly of cobbles is termed a conglomerate geology conglomerate . ref name Folk1980a Folk, R.L. 1980 The Petrology of Sedimentary Rocks. Austin, Texas, Hemphill Publishing Company. 182 pp. ISBN 100914696149 ref References reflist See also Gravel Particle size grain size Category Stone Category Sedimentology Category Granular materials petrology stub ... more details
A granule is a clastic rocks clast of rockgeologyrock with a particle size of 2 to 4 millimetres based on the Particle size grain size Krumbein phi scale of sedimentology . Granules are generally considered to be larger than sand 0.0625 to 2 millimetres diameter and smaller than pebble s 4 to 64 millimetres diameter . A rock made predominantly of granules is termed a conglomerate geology conglomerate . ref name Folk1980a Folk, R.L. 1980 The Petrology of Sedimentary Rocks. Austin, Texas, Hemphill Publishing Company. 182 pp. ISBN 0 914696 14 9 ref References reflist See also Gravel Particle size grain size Category Stone Category Sedimentology Category Granular materials petrology stub ... more details
from the west the hard competency geology competent crystalline rock crystalline rocks of these external ...dablink This article is about the geology of the European Alps . For the main article see geology of the Alps Geology of the Alps The Helvetic zone , Helvetic system or the Helveticum is a geology geologic subdivision of the Alps. The Helvetic zone outcrop crops out mainly in Switzerland , hence the name derived from Helveticus Latin for Swiss . Rocks in the Helvetic zone are sedimentary rock sedimentary and were originally sedimentation deposited at the southern continental margin margin of the Europe European plate . The Helvetic zone correlation correlates with the France French Dauphinois zone , French geologists often prefer the French name but normally this is considered the same thing. Occurrence In Switzerland the Helvetic zone is found in outcrops on the northern side of the Alpine mountain ranges. The French Alps consist mainly of Helvetic Dauphinois material. In Germany and Austria the Helvetic nappes crop out as a narrow band. Subdivision The Helvetic zone consists of a number of tectonics tectonically very different units. The Helvetic nappes are a nappe stack that was thrusted over the molasse of the Molasse basin in the Alpine foreland . They are composed of Mesozoic Marine ocean marine limestone , marl s and shale s. The Helvetic nappes are completely Decollement detached from their former basement geology basement . The Helvetic nappes are thrusted over the Infrahelvetic ... autochthonous Mesozoic sediments on top of Hercynian orogeny Hercynian basement rock. The Mesozoic ... deformation geology deformed by thrusting and Fold geology ffold ing that continues into the Hercynian ... were formed, places where the Hercynian basement rock crops out in large anticlinorium anticlinoria ... Members Schmid alps schmid html Text Schmid.html Geology of the western and central Alps, website of S.M. Schmid Category Geology of the Alps Category Structural geology Category Geology of Switzerland ... more details
Unreferenced stub auto yes date December 2009 image thrust system en.jpg thumb right 350px Schematic overview of a thrust system. The fault geology hanging wall block is when it has reasonable proportions called a nappe . If an erosion al hole is created in the nappe that is called a window. A klippe is a solitary outcrop of the nappe in the middle of autochthonous material. A tectonics tectonic window or Fenster lit. window in German language German is a geology geologic structure formed by erosion or normal fault ing on a thrust fault thrust system. In such a system the rock mass fault geology hanging wall block that has been transported by movement along the thrust is called a nappe . When erosion or normal faulting produces a hole in the nappe where the underlying autochthonous i.e. un transported rocks outcrop crop out this is called a window. Windows can be almost any size, from a couple of meter s to hundreds of kilometer s. wiktionary autochthonous DEFAULTSORT Window Geology Category Structural geology Category German words and phrases Geology stub de Fenster Geologie es Ventana tect nica fr Fen tre g ologie it Finestra tettonica nl Venster geologie nds Finster Geologie pl okno tektoniczne ... more details
Image Millook cliffs enh.jpg right thumb 300px Chevron folds with flat lying axial planes, Millook Haven, North Cornwall, UK About folds in rock layers deposits of sediment across the earth s surface Chevron land form A chevron in geology refers to a chevron shaped Fold geology fold in stratum layers. Chevron folds are generally close to tight interlimb angles 70 to 10 degrees with straight limbs and small angular hinges. They typically form in multilayers, consisting of regular alternations of beds with contrasting mechanical properties e.g. sandstones and mudstones. External links http mouser.org gallery ny roadcut chevron A chevron at a road cut http www.skidmore.edu jthomas JJT 20Home 20Page Texas 202005 Texas 20Web 20Pictures 202005 24 20OOR, 20Chevron 20Folds, 20Tinaja 20Rd.jpg Chevron in Texas Category Structural geology geology stub ... more details
a volcano . Fractures are generally produced as strain mechanics strain due to natural stress on the rock ..., etc. of soil and rock masses in, for example, tunnel , Foundation engineering foundation , or Slope ... References Gudmundsson, Agust 2011 Rock Fractures in Geological Processes Cambridge University Press, Cambridge, England, ISBN 978 0 521 86392 6 DEFAULTSORT Fracture Geology Category Structural geology Category Patterned grounds Geology stub ca Fractura geologia de Fissur Zahn et Rike geoloogia ... geology sk Puklina ... more details
The geology of Oman includes varied landscapes which are a blend of its geological history, and its climate over the past few million years. Rock outcrops in the Al Hajar Mountains , the Huqf and Dhofar are a point of interest for international geologists. The rock record spans about 825 million years and includes at least three periods when the country was covered by ice. Oman , located at the southeast corner of the Arabian plate , is being pushed slowly northward, as the Red Sea grows wider. The lofty Al Hajar Mountains and the drowned valleys of Musandam are dramatic reminders of this. Generally speaking Oman is fairly quiescent tectonically. Musandan experiences occasional tremors as the Arabian Plate collides with the Eurasian Plate . During the Cretaceous Period Oman was located adjacent to a subduction zone and a portion of the upper Mantle geology mantle along with overlying seafloor volcanic rock s were Thrust fault thrust over the continental crust . This obduction obducted sequence of ultramafic to mafic rocks is the Semail ophiolite complex. The ophiolite is locally rich in copper and chromite Ore orebodies . ref Guilbert, John M. and Charles F. Park, Jr., 1984, The Geology of Ore Deposits , Freeman, p. 380 382 ISBN 0 7167 1456 6 ref ref Dilek, Yildirim et.al, eds. 2001, Ophiolites and Oceanic Crust , Geological Society of America, p. 57, ISBN 0 8137 2349 3 ref The interior plains of Oman are of young sedimentary rock s, wadi gravels, dune sands and salt flat s. Beneath them is a several kilometre thick stack of older sedimentary rocks that host the country s hydrocarbon resources. Ancient salt, which comes to the surface in several salt dome s such as Qarat Kibrit , plays an important role in forming many of these oil and gas accumulations. References reflist ... montp2.fr omanophiolite pages1 sommaire.htm Asia topic Geology of Category Geology of Oman Category Geography of Oman regional geology stub ... more details
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