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Encyclopedia > Geology
World geologic provinces Oceanic crust ██ 0-20 Ma ██ 20-65 Ma ██ >65 Ma Geologic provinces ██ Shield ██ Platform ██ Orogen ██ Basin ██ Large igneous province ██ Extended crust
World geologic provinces
Oceanic crust ██ 0-20 Ma ██ 20-65 Ma ██ >65 Ma Geologic provinces ██ Shield ██ Platform ██ Orogen ██ Basin ██ Large igneous province ██ Extended crust

Geology (from Greek γη- (ge-, "the earth") and λογος (logos, "word", "reason")) is the science and study of the solid matter of the Earth, its composition, structure, physical properties, history and the processes that shape it. It is one of the Earth sciences. Geologists have helped establish the age of the Earth at about 4.6 billion (4.6x109) years, and have determined that the Earth's lithosphere, which includes the crust, is fragmented into tectonic plates that move over a rheic upper mantle (asthenosphere) via processes that are collectively referred to as plate tectonics. Geologists help locate and manage the Earth's natural resources, such as petroleum and coal, as well as metals such as iron, copper, and uranium. Additional economic interests include gemstones and many minerals such as asbestos, perlite, mica, phosphates, zeolites, clay, pumice, quartz, and silica, as well as elements such as sulfur, chlorine, and helium. Geology is a publication of the Geological Society of America. ... Image File history File links Download high resolution version (1200x637, 114 KB) Map of world geologic provinces. ... Image File history File links Download high resolution version (1200x637, 114 KB) Map of world geologic provinces. ... Age of oceanic crust Oceanic crust is the part of Earths lithosphere which underlies the ocean basins. ... A geologic province is a spatial entity with common geologic attributes. ... Shields are shown in orange. ... In geology, a platform is a continental area covered by relatively flat or gently tilted, mainly sedimentary strata, which overly a basement of consolidated igneous or metamorphic rocks of an earlier deformation. ... Orogeny is the process of mountain building, and as such is both a tectonic structural event, a geographical event and a chronological event, in that orogenic events happen within a time frame, affect certain regions of rocks and crust, and cause distinctive structural phenomena and related tectonic activity. ... A basin is the inverse of a dome: a symmetrically-dipping syncline that appears on a geologic map as roughly circular or elliptical, with concentric layers. ... Volcanic rock on North America Plutonic rock on North America Igneous rocks are formed when rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Earth cutaway from core to exosphere. ... Look up logos, λόγος in Wiktionary, the free dictionary. ... Part of a scientific laboratory at the University of Cologne. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. ... The Geologist by Carl Spitzweg A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology). ... A color image of Earth as seen from Apollo 17. ... The tectonic plates of the Lithosphere on Earth. ... Earth cutaway from core to exosphere. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... In geology, a rheid is a solid material that deforms by viscous flow. ... Earth cutaway from core to exosphere. ... Dont be afraid of big words. ... Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ... Pracsamp 07:34, 16 February 2007 (UTC)— Pumpjack pumping an oil well near Sarnia, Ontario Ignacy Łukasiewicz - inventor of the refining of kerosene from crude oil. ... Coal Coal (IPA: ) is a fossil fuel extracted from the ground by coal mining, either underground mining or open-pit mining (surface mining). ... For alternative meanings see metal (disambiguation). ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic pinkish red Atomic mass 63. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... Fibrous asbestos on muscovite Asbestos Asbestos Asbestos (a misapplication of Latin: asbestos quicklime from Greek : a, not and sbestos, extinguishable) describes any of a group of minerals that can be fibrous, many of which are metamorphic and are hydrous magnesium silicates. ... Expanded Perlite Perlite is an amorphous volcanic glass that has a relatively high water content. ... For other uses, see Mica (disambiguation). ... In chemistry, a phosphate is a polyatomic ion or radical consisting of one phosphorus atom and four oxygen. ... Categories: Silicate minerals | Mineral stubs ... The Gay Head cliffs in Marthas Vineyard are made almost entirely of clay. ... Specimen of highly porous pumice from Teide volcano on Tenerife, Canary Islands. ... Quartz is one of the most common minerals in the Earths continental crust. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ...


Planetary geology (sometimes known as Astrogeology) refers to the application of geologic principles to other bodies of the solar system. However, specialised terms such as selenology (studies of the Moon), areology (of Mars), etc., are also in use. Astrogeology is the scientific discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. ... Apparent magnitude: up to -12. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ...


The word "geology" was first used by Jean-André Deluc in the year 1778 and introduced as a fixed term by Horace-Bénédict de Saussure in the year 1779. The science was not included in Encyclopedia Britannica's third edition completed in 1797, but had a lengthy entry in the fourth edition completed by 1809.[1] An older meaning of the word was first used by Richard de Bury to distinguish between earthly and theological jurisprudence. Jean-André Deluc (8 February 1727 - 7 November 1817) was a Swiss geologist and meteorologist. ... Horace-Bénédict de Saussure (February 17, 1740 - January 22, 1799) was a Swiss physicist and Alpine traveller. ... 1913 advertisement for the 11th edition, with the slogan When in doubt — look it up in the Encyclopædia Britannica The Encyclopædia Britannica (properly spelled with æ, the ae-ligature) was first published in 1768–1771 as The Britannica was an important early English-language general encyclopedia and is still... Richard Aungerville (or Aungervyle) (January 24, 1287 - April 14, 1345), commonly known as Richard de Bury, was an English writer and bishop, He was born near Bury St Edmunds, Suffolk, the son of Sir Richard Aungervyle, who was descended from one of William the Conquerors men. ... Theology (Greek θεος, theos, God, + λογια, logia, words, sayings, or discourse) is reasoned discourse concerning religion, spirituality and God or the gods. ...

Contents

History

Main article: History of geology

In China, the polymath Shen Kua (1031 - 1095) formulated a hypothesis for the process of land formation: based on his observation of fossil shells in a geological stratum in a mountain hundreds of miles from the ocean, he inferred that the land was formed by erosion of the mountains and by deposition of silt. Wikipedia does not yet have an article with this exact name. ... Leonardo da Vinci is seen as an epitome of the Renaissance man or polymath A polymath (Greek polymathÄ“s, πολυμαθής, meaning knowing, understanding, or having learnt in quantity, compounded from πολυ- much, many, and the root μαθ-, meaning learning, understanding[1]) is a person well educated in a wide variety of subjects or... Shen Kuo or Shen Kua (Chinese: 沈括; pinyin: ) (1031 - 1095) Chinese scientist, polymath, general, diplomat, financial officer was the inventor of compasses for navigation. ... Three small ammonite fossils, each approximately 1. ... Various seashells The hard, rigid outer covering of certain animals is called a shell. ... Goldenville Strata exposed at a quarry in Bedford, Canada. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as understood by materials science, see Erosion (materials science) For erosion as an English analogy, see Erosion (figurative) Erosion is the displacement of solids (soil, mud, rock and other particles) by the agents of wind, water... Lyskamm in the Pennine Alps (4,527 m) A mountain is a landform that extends above the surrounding terrain in a limited area. ... Deposition, also known as sedimentation, is the geological process whereby material is added to a landform. ... Silt is soil or rock derived granular material of a specific grain size. ...


The work Peri lithon (On Stones) by Theophrastus (372 - 287 BC), a student of Aristotle, remained authoritative for millennia. Its interpretation of fossils was not overturned until after the Scientific Revolution. It was translated into Latin and the other languages of Europe such as French. Theophrastus (Greek Θεόφραστος, 370 — about 285 BC), a native of Eressos in Lesbos, was the successor of Aristotle in the Peripatetic school. ... Aristotle (Greek: Aristotélēs) (384 BC – March 7, 322 BC) was a Greek philosopher, a student of Plato and teacher of Alexander the Great. ... // The event which most historians of science call the scientific revolution can be dated roughly as having begun in 1543, the year in which Nicolaus Copernicus published his De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) and Andreas Vesalius published his De humani corporis fabrica (On the... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ...


Georg Agricola (1494-1555)), a physician, wrote the first systematic treatise about mining and smelting works, De re metallica libri XII, with an appendix Buch von den Lebewesen unter Tage (Book of the Creatures Beneath the Earth). He covered subjects like wind energy, hydrodynamic power, melting cookers, transport of ores, extraction of soda, sulfur and alum, and administrative issues. The book was published in 1556. Nicolas Steno (1638-1686) is credited with the law of superposition, the principle of original horizontality, and the principle of lateral continuity: three defining principles of stratigraphy. Georg Agricola Georgius Agricola (March 24, 1494 – November 21, 1555) was a German scholar and man of science. ... 1494 was a common year starting on Monday (see link for calendar) of the Gregorian calendar. ... Events Russia breaks 60 year old truce with Sweden by attacking Finland February 2 - Diet of Augsburg begins February 4 - John Rogers becomes first Protestant martyr in England February 9 - Bishop of Gloucester John Hooper is burned at the stake May 23 - Paul IV becomes Pope. ... This article is about mineral extraction. ... Electric phosphate smelting furnace in a TVA chemical plant (1942) Chemical reduction, or smelting, is a form of extractive metallurgy. ... Georg Agricola the father of mineralogy De re metallica (Latin for On the Nature of Metals (Minerals)) is a book cataloging the state of the art of mining, refining, and smelting metals, published in 1556. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Undershot water wheels on the Orontes River in Hama, Syria Saint Anthony Falls Hydropower is the capture of the energy of moving water for some useful purpose. ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ... Look up soda in Wiktionary, the free dictionary. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... A crystal of Alum Alum, in chemistry, is a term given to the crystallized double sulfates of the typical formula M+2SO4·M3+2(SO4)3·24H2O, where M+ is the sign of an alkali metal (lithium, sodium, potassium, rubidium, or caesium), and M3+ denotes one of the trivalent metal... Events January 16 - Abdication of Emperor Charles V. His son, Philip II becomes King of Spain, while his brother Ferdinand becomes Holy Roman Emperor January 23 - The Shaanxi earthquake, the deadliest earthquake in history, occurs with its epicenter in Shaanxi province, China. ... Nicolaus Steno. ... Events March 29 - Swedish colonists establish first settlement in Delaware, called New Sweden. ... 1686 (MDCLXXXVI) was a common year starting on Tuesday of the Gregorian calendar (or a common year starting on Friday of the 10-day slower Julian calendar). ... The law of superposition (or the principle of superposition) is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields dealing with stratigraphy. ... Proposed by Nicholas Steno. ... The principle of lateral continuity states that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. ... Stratigraphy, a branch of geology, is basically the study of rock layers and layering (stratification). ...


By the 1700s Jean-Étienne Guettard and Nicolas Desmarest hiked central France and recorded their observations on geological maps; Guettard recorded the first observation of the volcanic origins of this part of France. Events and trends The Bonneville Slide blocks the Columbia River near the site of present-day Cascade Locks, Oregon with a land bridge 200 feet (60 m) high. ... Jean-Étienne Guettard (September 22, 1715 - January 7, 1786), French naturalist and mineralogist, was born at Etampes. ... Nicolas Desmarest (September 16, 1725 - September 20, 1815) was a French geologist. ... A geologic map is a special-purpose map made for the purpose of showing subsurface geological features. ... For other uses, see Volcano (disambiguation). ...


William Smith (1769-1839) drew some of the first geological maps and began the process of ordering rock strata (layers) by examining the fossils contained in them. William Smith. ... 1769 was a common year starting on Sunday (see link for calendar). ... 1839 (MDCCCXXXIX) was a common year starting on Tuesday (see link for calendar). ... Interstate road cut through limestone and shale strata in eastern Tennessee In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. ...


James Hutton is often viewed as the first modern geologist. In 1785 he presented a paper entitled Theory of the Earth to the Royal Society of Edinburgh. In his paper, he explained his theory that the Earth must be much older than had previously been supposed in order to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea, which in turn were raised up to become dry land. Hutton published a two-volume version of his ideas in 1795 (Vol. 1, Vol. 2). James Hutton, painted by Abner Lowe. ... 1785 was a common year starting on Saturday (see link for calendar). ... The Royal Society of Edinburghs Building on the corner of George St. ... Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ... 1795 was a common year starting on Thursday (see link for calendar). ...

The geologist, 19th century painting by Carl Spitzweg.
The geologist, 19th century painting by Carl Spitzweg.

Followers of Hutton were known as Plutonists because they believed that some rocks were formed by vulcanism which is the deposition of lava from volcanoes, as opposed to the Neptunists, who believed that all rocks had settled out of a large ocean whose level gradually dropped over time. Image File history File links Download high-resolution version (2024x2608, 692 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Geology User:Rl/Images ... Image File history File links Download high-resolution version (2024x2608, 692 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Geology User:Rl/Images ... The Poor Poet, 1839. ... Plutonism was a theory of Geology around the turn of the 19th Century that claimed that volcanic activity was the source of rocks on the surface of the Earth. ... This article is about volcanoes in geology. ... For other uses, see Volcano (disambiguation). ... Neptunism is a discredited and obsolete scientific theory of geology proposed in the late 18th century and early 19th century that proposed rocks formed from the crystallization of minerals in the early Earths oceans. ...


In 1811 Georges Cuvier and Alexandre Brongniart published their explanation of the antiquity of the Earth, inspired by Cuvier's discovery of fossil elephant bones in Paris. To prove this, they formulated the principle of stratigraphic succession of the layers of the earth. They were independently anticipated by William Smith's stratigraphic studies on England and Scotland. 1811 was a common year starting on Tuesday (see link for calendar). ... Georges Cuvier Baron Georges Léopold Chrétien Frédéric Dagobert Cuvier (August 23, 1769–May 13, 1832) was a French naturalist and zoologist. ... Alexandre Brongniart (1770 – 1847) was a French chemist and zoologist, who collaborated with Georges Cuvier. ... Stratigraphy, a branch of geology, is basically the study of rock layers and layering (stratification). ... William Smith. ...


By 1827 Charles Lyell's Principles of Geology reiterated Hutton's uniformitarianism, which influenced the thought of Charles Darwin. Naval Battle of Navarino by Carneray 1827 was a common year starting on Monday (see link for calendar). ... Charles Lyell The frontispiece from Principles of Geology Sir Charles Lyell, 1st Baronet, KT, (November 14, 1797 – February 22, 1875), Scottish lawyer, geologist, and populariser of uniformitarianism. ... Charles Robert Darwin (12 February 1809 – 19 April 1882) was an eminent English naturalist who achieved lasting fame by convincing the scientific community that species develop over time from a common origin. ...


Sir Charles Lyell first published his famous book, Principles of Geology, in 1830 and continued to publish new revisions until he died in 1875. He successfully promoted the doctrine of uniformitarianism. This theory states that slow geological processes have occurred throughout the Earth's history and are still occurring today. In contrast, catastrophism is the theory that Earth's features formed in single, catastrophic events and remained unchanged thereafter. Though Hutton believed in uniformitarianism, the idea was not widely accepted at the time. Charles Lyell Sir Charles Lyell (November 14, 1797 РFebruary 22, 1875), British geologist, and popularizer of uniformitarianism. ... Liberty Leading the People by Eug̬ne Delacroix commemorates the July Revolution 1830 (MDCCCXXX) was a common year starting on Friday (see link for calendar). ... 1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ... Uniformitarianism, in the philosophy of science, is the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present. ... The planet Earth, photographed in the year 1972. ... Catastrophism is the theory that Earth has been affected by sudden, short-lived, violent events that were sometimes worldwide in scope. ...

Plate tectonics - seafloor spreading and continental drift illustrated on relief globe of the Field Museum
Plate tectonics - seafloor spreading and continental drift illustrated on relief globe of the Field Museum

19th Century geology revolved around the question of the Earth's exact age. Estimates varied from a few 100,000 to billions of years. The most significant advance in 20th century geology has been the development of the theory of plate tectonics in the 1960s. Plate tectonic theory arose out of two separate geological observations: seafloor spreading and continental drift. The theory revolutionized the Earth sciences. Wegeners theory of Continental Drift, vindicated by Plate tectonics and Seafloor spreading, illustrated by Relief Globe at Field Museum File links The following pages link to this file: Geology History of science Image:Wegener. ... Wegeners theory of Continental Drift, vindicated by Plate tectonics and Seafloor spreading, illustrated by Relief Globe at Field Museum File links The following pages link to this file: Geology History of science Image:Wegener. ... Age of oceanic crust. ... Plates in the crust of the earth, according to the plate tectonics theory Continental drift, proposed as a theory by Alfred Wegener in 1912, is the movement of the Earths continents relative to each other. ... Field Museum of Natural History, Chicago The Field Museum of Natural History, in Chicago, Illinois, USA, sits on Lake Shore Drive next to Lake Michigan, part of a scenic complex called known as the Museum Campus which includes Soldier Field, the football stadium that is the home of the Chicago... A color image of Earth as seen from Apollo 17. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999... Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Age of oceanic crust. ... Plates in the crust of the earth, according to the plate tectonics theory Continental drift, proposed as a theory by Alfred Wegener in 1912, is the movement of the Earths continents relative to each other. ... Earth science (also known as geoscience or the geosciences), is an all-embracing term for the sciences related to the planet Earth. ...


The theory of continental drift was proposed by Frank Bursley Taylor in 1908, expanded by Alfred Wegener in 1912 and by Arthur Holmes, but wasn't broadly accepted until the 1960s when the theory of plate tectonics was developed. Frank Bursley Taylor, [b. ... Alfred Wegeners theory of continental drift was widely ridiculed in his day Alfred Lothar Wegener (Berlin, November 1, 1880 – Greenland, November 2 or 3, 1930) was a German interdisciplinary scientist and meteorologist, who became famous for his theory of continental drift. ... 1912 (MCMXII) was a leap year starting on Monday in the Gregorian calendar (or a leap year starting on Tuesday in the 13-day-slower Julian calendar). ... Arthur Holmes (January 14, 1890 – September 20, 1965) was a British geologist. ... The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ...


Important principles of geology

There are a number of important principles in geology. Many of these involve the ability to provide the relative ages of strata or the manner in which they were formed.


The principle of intrusive relationships concerns crosscutting intrusions. In geology, when an igneous intrusion cuts across a formation of sedimentary rock, it can be determined that the igneous intrusion is younger than the sedimentary rock. There are a number of different types of intrusions, including stocks, laccoliths, batholiths, sills and dikes. Pluton redirects here. ... Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... This article or section does not cite its references or sources. ... A laccolith is an igneous intrusion (or concordant pluton) that has been injected between two layers of sedimentary rock. ... Half Dome A batholith is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earths crust. ... In geology, a sill is a tabular, often horizontal mass of igneous rock that has been intruded laterally between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorphic rock. ... A dike in geology refers to a tabular intrusive igneous body. ...


The principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault. Geologic faults, fault lines or simply faults are planar rock fractures, which show evidence of relative movement. ... Old fault exposed by roadcut near Harrisburg, Pennsylvania. ... A thrust fault is a particular type of fault, or break in the fabric of the Earths crust with resulting movement of each side against the other, in which a lower stratigraphic position is pushed up and over another. ...


The principle of inclusions and components states that, with sedimentary rocks, if inclusions (or clasts) are found in a formation, then the inclusions must be older than the formation that contains them. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found. These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in the matrix. As a result, xenoliths are older than the rock which contains them. Clastic rocks refers to rocks formed from fragments of pre-existing rock. ... A xenolith A xenolith (Greek: foreign rock) is a rock fragment which becomes enveloped in a larger rock during the latters development and hardening. ... Magma is molten rock located beneath the surface of the Earth (or any other rocky planet), and which often collects in a magma chamber. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ...


The principle of uniformitarianism states that the geologic processes observed in operation that modify the Earth's crust at present have worked in much the same way over geologic time. A fundamental principle of geology advanced by the 18th century Scottish physician and geologist James Hutton, is that "the present is the key to the past." In Hutton's words: "the past history of our globe must be explained by what can be seen to be happening now." Uniformitarianism, in the philosophy of science, is the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present. ... James Hutton, painted by Abner Lowe. ...


The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds. Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units is horizontal). Proposed by Nicholas Steno. ... Cross bedding is a geological term referring to the way a sedimentary deposit is affected by water currents, during its formation. ...


The principle of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it. Logically a younger layer cannot slip beneath a layer previously deposited. This principle allows sedimentary layers to be viewed as a form of vertical time line, a partial or complete record of the time elapsed from deposition of the lowest layer to deposition of the highest bed. The law of superposition (or the principle of superposition) is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields dealing with stratigraphy. ...


The principle of faunal succession is based on the appearance of fossils in sedimentary rocks. As organisms exist at the same time period throughout the world, their presence or (sometimes) absence may be used to provide a relative age of the formations in which they are found. Based on principles laid out by William Smith almost a hundred years before the publication of Charles Darwin's theory of evolution, the principles of succession were developed independently of evolutionary thought. The principle becomes quite complex, however, given the uncertainties of fossilization, the localization of fossil types due to lateral changes in habitat (facies change in sedimentary strata), and that not all fossils may be found globally at the same time. This article or section does not cite its references or sources. ... William Smith. ... Charles Robert Darwin (12 February 1809 – 19 April 1882) was an eminent English naturalist who achieved lasting fame by convincing the scientific community that species develop over time from a common origin. ... This article is about biological evolution. ... The term facies was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy (see Cross and Homewood 1997), which replaced the earlier notions of Neptunism. ...


Fields or related disciplines

An illustrated depiction of a syncline and anticline commonly studied in Structural geology and Geomorphology.
An illustrated depiction of a syncline and anticline commonly studied in Structural geology and Geomorphology.
Oceanic-continental convergence resulting in subduction and volcanic arcs illustrates one effect of plate tectonics.
Oceanic-continental convergence resulting in subduction and volcanic arcs illustrates one effect of plate tectonics.

Image File history File links Download high resolution version (846x614, 192 KB) Summary Description: A scheme showing the syncline and anticline. ... Image File history File links Download high resolution version (846x614, 192 KB) Summary Description: A scheme showing the syncline and anticline. ... Road Cut near Ft. ... Anticline with syncline visible at far right- USGS In structural geology, an anticline is a Fold (geology) that is convex to the youngest beds—youngest sediments are on back of hand, older under the palm. ... Structural geology is the study of the three dimensional distribution of rock bodies and their planar or folded surfaces, and their internal fabrics. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. ... Economic geology is concerned with earth materials that can be utilized for economic and/or industrial purposes. ... This article is about mineral extraction. ... Petroleum geology is a term used to refer to the specific set of geological disciplines that are applied to the search for hydrocarbons (oil exploration). ... Engineering Geology is the application of the science of geology to the understanding of geologic phenomena and the engineering solution of geologic hazards and other geologic problems for society. ... Environmental geology, like hydrogeology, is a multidisciplinary field of applied science and is closely related to engineering geology and somewhat related to environmental geography. ... Geoarchaeology is a sub-field of archaeology which uses the techniques and subject matter of the earth sciences to examine topics which inform archaeological knowledge and thought. ... The field of geochemistry involves study of the chemical composition of the Earth and other planets, chemical processes and reactions that govern the composition of rocks and soils, and the cycles of matter and energy that transport the Earths chemical components in time and space, and their interaction with... The field of biogeochemistry involves scientific study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the hydrosphere, the pedosphere, the atmosphere, and the lithosphere), and the cycles of matter and energy that transport the Earths chemical... Isotope geochemistry is an aspect of Geology based upon study of the relative and absolute concentrations of the elements and their isotopes in the Earth. ... Geochronology is the science of determining the age of rocks, fossils, and sediments. ... This article or section should include material from Erdmessung. ... Geomicrobiology is a science that combines geology and microbiology, and studies the interaction of microscopic organisms with their inorganic environment, such as in sedimentary rocks. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... ‹ The template below has been proposed for deletion. ... Lateral moraine on a glacier joining the Gorner Glacier, Zermatt, Switzerland. ... Historical geology is the use of the principles of geology to reconstruct and understand the history of the Earth. ... Hydrogeology (hydro- meaning water, and -geology meaning the study of rocks) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust (commonly in aquifers). ... Hydrogeology (hydro- meaning water, and -geology meaning the study of rocks) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust (commonly in Aquifers). ... Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. ... Thermohaline circulation Oceanography (from Ocean + Greek γράφειν = write), also called oceanology or marine science, is the branch of Earth Sciences that studies the Earths oceans and seas. ... Oceanography (from Ocean + Greek γράφειν = write), also called oceanology and marine science is the study of the earths oceans and their interlinked ecosystems and chemical and physical processes. ... Paleoclimatology is the study of climate change taken on the scale of the entire history of the Earth. ... Paleontology, palaeontology or palæontology (see spelling differences) is the study of the history and development of life on Earth, including that of ancient plants and animals, based on the fossil record (evidence of their prehistoric existence as typically preserved in sedimentary rocks). ... Micropaleontology, the study of microfossils, is a branch of paleontology. ... Pollen under microscope Palynology is the science that studies contemporary and fossil palynomorphs, including pollen, spores, dinoflagellate cysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter (POM) and kerogen found in sedimentary rocks and sediments. ... Petrology is a field of geology which focuses on the study of rocks and the conditions by which they form. ... This article or section is in need of attention from an expert on the subject. ... Image File history File links Oceanic-continental_convergence_Fig21oceancont. ... Image File history File links Oceanic-continental_convergence_Fig21oceancont. ... The Juan de Fuca plate sinks below the North America plate at the Cascadia subduction zone. ... A volcanic arc is a chain of volcanic islands or mountains located near the edge of continents that are formed as the result of tectonic plate subduction. ... Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ... Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ... Sedimentology is the branch of geology primarily concerned with understanding the characteristics of sediments, sedimentary processes and sedimentary rocks originally deposited in sedimentary basins. ... Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the movement of waves through the Earth. ... Soil science deals with soil as a natural resource on the surface of the earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils per se; and these properties in relation to the use and management of soils. ... Pedology (pÄ›dÇ’lōgy), (from Russian: pedologiya, from the Greek pedon = soil, earth), is the study of soils and soil formation. ... Grotte des Faux-Monnayeurs, Switzerland Speleology is the scientific study of caves and other karst features, their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). ... Stratigraphy, a branch of geology, is basically the study of rock layers and layering (stratification). ... Biostratigraphy is the science of dating rocks by using the fossils contained within them. ... Chronostratigraphy is the branch of stratigraphy that studies the age of rock strata in relation to time. ... Lithostratigraphy is the geological science associated with the study of stratum or rock layers. ... Structural geology is the study of the three dimensional distribution of rock bodies and their planar or folded surfaces, and their internal fabrics. ... Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma, and related geological phenomena. ...

Regional geology

The Alps are a mountain range in Central Europe, this article describes the geology of the Alps. ... The geology of the Appalachians dates back to more than 480 million years ago. ... Fig 1: The earth in the Early Permian. ...

By Nations

  • Geology of Nigeria

page in progress // Overview Australia is a continent situated on the Indo-Australian Plate. ... // Geology Australia was created by the junction of three early pieces of continental crust (cratons). ... The Australian state of Victoria rests at the southern end of the Great Dividing Range, which stretches along the east coast and terminates near Ballarat. ... // The Yilgarn Craton is a huge craton which constitutes the bulk of the Western Australian land mass. ... The Geology of Europe is hugely varied and complex, and gives rise to the wide variety of landscapes found across the continent, from the Scottish Highlands to the rolling plains of Hungary. ... The geology of the Netherlands is very much influenced by its very low position. ... Geological map of Great Britain. ... Geological map of Great Britain, showing the differing geology of England, Scotland and Wales. ... Stylised simple Geology map of Dorset Dorset, England, rests on a variety of different rock types which give the county its interesting landscapes and habitats. ... Hampshires geology falls into two categories. ... The rocks of the English county of Hertfordshire belong to the great shallow syncline known as the London basin, the beds dip in a south-easterly direction towards the synclines lowest point roughly under the River Thames. ... Geological map of Great Britain. ... The Geology of Lizard (The Lizard Peninsula, Cornwall, United Kingdom) has been the subject of much study. ... Scotland has an incomparable variety of geology for an area of its size. ... Geological map of Great Britain. ... This article needs translation. ... This article is in need of attention from an expert on the subject. ... Sikkim (also Sikhim) (DevanāgarÄ«: सिक्किम  ) is a landlocked Indian state nestled in the Himalayas. ... The islands of Japan are primarily the result of volcanism caused by the subduction of the Philippine Plate and the pacific Plate beneath the continental Eurasian Plate. ... Sedimentary, volcanic, plutonic, metamorphic rock types of North America. ... Greetings from California, vintage large-letter postcard. ... As part of New England, Connecticut has undergone much geologic change shaped by plate tectonics, volcanism, and glacial activity. ... Shaded Relief Map of the Llano Estacado. ... The exposed geology of the Bryce Canyon area shows a record of deposition that covers the last part of the Cretaceous period and the first half of the Cenozoic era in that part of North America. ... The exposed geology of the Canyonlands area is complex and diverse; 12 formations are exposed in Canyonlands National Park that range in age from Pennsylvanian to Cretaceous. ... The Waterpocket Fold is the major geographic feature in the area of the park. ... The exposed geology of the Death Valley area presents a diverse and complex story that includes at least 23 formations of sedimentary units, two major gaps in the geologic record called unconformities, and at least one distinct set of related formations geologists call groups. ... The Grand Canyon from Navajo Point. ... The geology of the Grand Teton area consists of some of oldest rocks and one of the youngest mountain ranges in North America. ... The source of heat for volcanism in the Lassen Volcanic National Park area was, and still is, subduction off the Northern California coast of the Gorda Plate diving below the North American Plate. ... Mt. ... About 593,000 years ago andesitic lavas erupted in what is now Mount Shastas western flank near McBride Spring. ... The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. ... Kolob Canyons from the end of Kolob Canyons Road. ... The Genesee River flows northward from its source in northern Pennsylvania to enter Lake Ontario north of Rochester, New York. ...

Planetary geology

Surface of Mars as photographed by the Viking 2 lander December 9, 1977.
Surface of Mars as photographed by the Viking 2 lander December 9, 1977.

Image File history File links Viking2_frost_enhance. ... Image File history File links Viking2_frost_enhance. ...    Frost on Mars. ... December 9 is the 343rd day (344th in leap years) of the year in the Gregorian calendar. ... For the album by Ash, see 1977 (album). ... Of all the terrestrial planets in the Solar System, the geology of Mercury is the least understood. ... A global view of Venus made from a mosaic of radar images from the Magellan spacecraft, centred at 90 degrees longitude. ... Exploring Shorty crater during the Apollo 17 mission to the Moon. ... The geology of Mars, sometimes called areology, is the study of its composition, structure, physical properties, history and the processes that shape it. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% H2 ~13% Helium 0. ... Note: This article contains special characters. ... Adjectives: Uranian Atmosphere Surface pressure: 120 kPa (at the cloud level) Composition: 83% Hydrogen 15% Helium 1. ... Note: This article contains special characters. ...

See also

Timeline of geology: see also geologic timescale. ... This page is intended as a list of all rock types. ... Gem animals. ... This is a list of all articles related to geology that cannot be readily placed on the following subtopic pages: Geology subtopics Geologic timescale List of compounds List of earthquakes List of elements by name List of geologists List of fluvial topics List of landforms List of minerals List of... This page is intended to be a list of rock textural and morphological terms. ... The Geologist by Carl Spitzweg A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology). ... Geologic modeling is the applied science of creating computerized representations of portions of the Earths crust, especially oil and gas fields and groundwater aquifers. ... // For other uses, see time scale. ... Minerals are natural compounds formed through geological processes. ... IUGS logo The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology. ... The International Union of Geological Sciences (IUGS) was founded in 1961 and is a Scientific Union member of the International Council for Science (ICSU), which it recognizes as the coordinating body for the international organization of science. ... // Foundations Principles of Geology Author: Charles Lyell Publication data: 1830–1833. ...

External links

References

  1. ^ Winchester, Simon (2001). The Map that Changed the World. HarperCollins Publishers, 25.  ISBN 0-06-093180-9

  Results from FactBites:
 
Geology - MSN Encarta (1015 words)
Geology, study of the planet earth, its rocky exterior, its history, and the processes that act upon it.
The word geology comes from the Greek geo, “earth,” and logia, “the study of.” Geologists seek to understand how the earth formed and evolved into what it is today, as well as what made the earth capable of supporting life.
The field of geology includes subfields that examine all of the earth's systems, from the deep interior core to the outer atmosphere, including the hydrosphere (the waters of the earth) and the biosphere (the living component of earth).
The Geology Department, University of California, Davis (271 words)
UCD Geology faculty, staff and students are outstanding in their field.
Read about the latest work being done by UC Davis Geology faculty and researchers in the Fall edition of College Currents, the UC Davis College of Letters and Science Magazine.
Geology Department • University of California • One Shields Avenue • Davis, CA USA 95616-8605
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