1.
Lithology
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It may be either a detailed description of these characteristics or be a summary of the gross physical character of a rock. It is the basis of subdividing rock sequences into individual lithostratigraphic units for the purposes of mapping, in certain applications, such as site investigations, lithology is described using a standard terminology such as in the European geotechnical standard Eurocode 7. The naming of a lithology is based on the rock type, the three major rock types are sedimentary, igneous, metamorphic. Sedimentary rocks are classified by whether they are siliciclastic or carbonate. Siliciclastic sedimentary rocks are then subcategorized based on their size distribution and the relative proportions of quartz, feldspar. Carbonate rocks are classified with the Dunham or Folk classification schemes according to the constituents of the carbonate rock, the name of an igneous rock requires information on crystal size and mineralogy. This classification can often be performed with a QAPF diagram, metamorphic rock naming can be based on texture, protolith, metamorphic facies, and/or the locations in which they are found. Naming based on texture and a pelite protolith can be used to slate and phyllite. Texture-based names are schist and gneiss and these textures, from slate to gneiss, define a continually-increasing extent of metamorphism. Metamorphic facies are defined by the fields in which particular minerals form. In igneous and metamorphic rocks, grain size is a measure of the sizes of the crystals in the rock. In igneous rock, this is used to determine the rate at which the material cooled, large crystals typically indicate intrusive igneous rock, as metamorphic reactions progress, the grains in metamorphic rocks can often be broken down into smaller grains. In clastic sedimentary rocks, grain size is the diameter of the grains and/or clasts that constitute the rock and these are used to determine which rock naming system to use. In the case of sandstones and conglomerates, which cover a range of grain sizes. Examples are pebble conglomerate and fine quartz arenite, in rocks in which mineral grains are large enough to be identified using a hand lens, the visible mineralogy is included as part of the description. The mineralogical composition of a rock is one of the ways in which it is classified. In general, igneous rocks can be categorized by increasing silica content as ultramafic, mafic, intermediate, or felsic, the fabric of a rock describes the spatial and geometric configuration of all the elements that make it up. In sedimentary rocks the main fabric is normally bedding and the scale
2.
Outcrop
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An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. However, in places where the cover is removed through erosion or tectonic uplift. In Finland, glacial erosion during the last glacial maximum, followed by scouring by sea waves, bedrock and superficial deposits may also be exposed at the Earths surface due to human excavations such as quarrying and building of transport routes. Outcrops allow direct observation and sampling of the bedrock in situ for geologic analysis, in situ measurements are critical for proper analysis of geological history and outcrops are therefore extremely important for understanding the geologic time scale of earth history. Outcrops are also important for understanding fossil assemblages, paleo-environment. An outcrop example in California is the Vasquez Rocks, familiar from location shooting use in many films, list of rock formations Geological formation Geologic time scale Media related to Outcrops at Wikimedia Commons
3.
Core sample
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A core sample is a cylindrical section of a naturally occurring substance. Most core samples are obtained by drilling with special drills into the substance, for example sediment or rock, the hole made for the core sample is called the core bowling. A variety of core samplers exist to sample different media under different conditions, more continue to be invented on a regular basis. In the coring process, the sample is pushed more or less intact into the tube, removed from the tube in the laboratory, it is inspected and analyzed by different techniques and equipment depending on the type of data desired. Core samples can be taken to test the properties of materials, such as concrete, ceramics, some metals and alloys. Core samples can also be taken of living things, including human beings, the range of equipment and techniques applied to the task is correspondingly great. Core samples are most often taken with their axis oriented roughly parallel to the axis of a borehole. However it is possible to take core samples from the wall of an existing borehole. Taking samples from an exposure, albeit an overhanging rock face or on a different planet, is almost trivial. The penetration forces, if recorded, give information about the strength of different depths in the material and this technique is common in both civil engineering site investigations and geological studies of recent aquatic deposits. The low strength of the materials penetrated means that cores have to be relatively small, vibracoring, in which the sampler is vibrated to allow penetration into thixotropic media. Again, the strength of the subject material limits the size of core that can be retrieved. A mechanism is normally needed to retain the cylindrical sample in the coring tool, the mechanical forces imposed on the core sample by the tool frequently lead to fracture of the core and loss of less-competent intervals, which can greatly complicate interpretation of the core. Cores can routinely be cut as small as a few millimeters in diameter up to over 150 millimeters in diameter, percussion sidewall coring uses robust cylindrical bullets explosively propelled into the wall of a borehole to retrieve a small, short core sample. These tend to be shattered, rendering porosity/ permeability measurements dubious. Many samples can be attempted in a run of the tools. Several tools can often be ganged together for a single run and this is an important consideration in planning sample programmes. Rotary sidewall coring where a miniaturised automated rotary drilling tool is applied to the side of the borehole to cut a sample similar in size to a percussion sidewall core and these tend to suffer less deformation than percussion cores
4.
United States Geological Survey
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The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its resources. The organization has four science disciplines, concerning biology, geography, geology. The USGS is a research organization with no regulatory responsibility. The USGS is a bureau of the United States Department of the Interior, the USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, the current motto of the USGS, in use since August 1997, is science for a changing world. The agencys previous slogan, adopted on the occasion of its anniversary, was Earth Science in the Public Service. Prompted by a report from the National Academy of Sciences, the USGS was created, by a last-minute amendment and it was charged with the classification of the public lands, and examination of the geological structure, mineral resources, and products of the national domain. This task was driven by the need to inventory the vast lands added to the United States by the Louisiana Purchase in 1803, the legislation also provided that the Hayden, Powell, and Wheeler surveys be discontinued as of June 30,1879. Clarence King, the first director of USGS, assembled the new organization from disparate regional survey agencies, after a short tenure, King was succeeded in the directors chair by John Wesley Powell. Administratively, it is divided into a Headquarters unit and six Regional Units, Other specific programs include, Earthquake Hazards Program monitors earthquake activity worldwide. The National Earthquake Information Center in Golden, Colorado on the campus of the Colorado School of Mines detects the location, the USGS also runs or supports several regional monitoring networks in the United States under the umbrella of the Advanced National Seismic System. The USGS informs authorities, emergency responders, the media, and it also maintains long-term archives of earthquake data for scientific and engineering research. It also conducts and supports research on long-term seismic hazards, USGS has released the UCERF California earthquake forecast. The USGS National Geomagnetism Program monitors the magnetic field at magnetic observatories and distributes magnetometer data in real time, the USGS operates the streamgaging network for the United States, with over 7400 streamgages. Real-time streamflow data are available online, since 1962, the Astrogeology Research Program has been involved in global, lunar, and planetary exploration and mapping. USGS operates a number of related programs, notably the National Streamflow Information Program. USGS Water data is available from their National Water Information System database
5.
Petroleum industry
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The petroleum industry includes the global processes of exploration, extraction, refining, transporting, and marketing of petroleum products. The largest volume products of the industry are fuel oil and gasoline, Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, synthetic fragrances, and plastics. The industry is divided into three major components, upstream, midstream and downstream. Midstream operations are included in the downstream category. Petroleum is vital to many industries, and is of importance to the maintenance of industrial civilization in its current configuration, and thus is a critical concern for many nations. Oil accounts for a percentage of the world’s energy consumption, ranging from a low of 32% for Europe and Asia. Other geographic regions consumption patterns are as follows, South and Central America, Africa, the world consumes 30 billion barrels of oil per year, with developed nations being the largest consumers. The United States consumed 25% of the oil produced in 2007, the production, distribution, refining, and retailing of petroleum taken as a whole represents the worlds largest industry in terms of dollar value. Petroleum is a naturally occurring liquid found in rock formations and it consists of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds. It is generally accepted that oil is formed mostly from the carbon rich remains of ancient plankton after exposure to heat, Petroleum in an unrefined state has been utilized by humans for over 5000 years. Oil in general has been used since early history to keep fires ablaze. Its importance to the world economy evolved slowly, with oil used for lighting in the 19th century and wood. The Industrial Revolution generated an increasing need for energy which was met mainly by coal, Imperial Russia produced 3,500 tons of oil in 1825 and doubled its output by mid-century. Batum is renamed to Batumi in 1936, at the turn of the 20th century, Imperial Russias output of oil, almost entirely from the Apsheron Peninsula, accounted for half of the worlds production and dominated international markets. Nearly 200 small refineries operated in the suburbs of Baku by 1884, as a side effect of these early developments, the Apsheron Peninsula emerged as the worlds oldest legacy of oil pollution and environmental negligence. In 1846, Baku the first ever well drilled with percussion tools to a depth of 21 meters for oil exploration, in 1878, Ludvig Nobel and his Branobel company revolutionized oil transport by commissioning the first oil tanker and launching it on the Caspian Sea. Samuel Kier established Americas first oil refinery in Pittsburgh on Seventh avenue near Grant Street, one of the first modern oil refineries were built by Ignacy Łukasiewicz near Jasło, Poland in 1854–56. These were initially small as demand for refined fuel was limited, the refined products were used in artificial asphalt, machine oil and lubricants, in addition to Łukasiewiczs kerosene lamp
6.
Reflection seismology
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Reflection seismology is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earths subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite/Tovex, Reflection seismology is similar to sonar and echolocation. This article is about surface seismic surveys, for vertical seismic profiles, Seismic waves are mechanical perturbations that travel in the Earth at a speed governed by the acoustic impedance of the medium in which they are travelling. The acoustic impedance, Z, is defined by the equation, Z = V ρ, in common with other geophysical methods, reflection seismology may be seen as a type of inverse problem. In the case of reflection seismology, the data are recorded seismograms. For these reasons, great care must be taken when interpreting the results of a seismic survey. These reflected energy waves are recorded over a time period by receivers that detect the motion of the ground in which they are placed. On land, the receiver used is a small, portable instrument known as a geophone. In water, hydrophones are used, which convert pressure changes into electrical signals, each receiver’s response to a single shot is known as a “trace” and is recorded onto a data storage device, then the shot location is moved along and the process is repeated. In general, the complex the geology of the area under study. Modern seismic reflection surveys contain large amount of data and so large amounts of computer processing. Similarly, the amplitude of the incident wave is multiplied by the coefficient to predict the amplitude of the wave transmitted through the boundary. The formula for the transmission coefficient is T =1 − R =2 Z1. By observing changes in the strength of reflectors, seismologists can infer changes in the seismic impedances, in turn, they use this information to infer changes in the properties of the rocks at the interface, such as density and elastic modulus. The situation becomes more complicated in the case of non-normal incidence. These equations have 4 unknowns and can be solved but they do not give an understanding for how the reflection amplitudes vary with the rock properties involved. The reflection and transmission coefficients, which govern the amplitude of each reflection, vary with angle of incidence, AVO studies attempt with some success to predict the fluid content of potential reservoirs, to lower the risk of drilling unproductive wells and to identify new petroleum reservoirs. The 3-term simplification of the Zoeppritz equations that is most commonly used was developed in 1985 and is known as the Shuey equation and this equation reduces to that of normal incidence at =0
7.
Mineralogy
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Mineralogy is a subject of geology specializing in the scientific study of chemistry, crystal structure, and physical properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, the German Renaissance specialist Georgius Agricola wrote works such as De re metallica and De Natura Fossilium which began the scientific approach to the subject. Systematic scientific studies of minerals and rocks developed in post-Renaissance Europe, the modern study of mineralogy was founded on the principles of crystallography and to the microscopic study of rock sections with the invention of the microscope in the 17th century. Nicholas Steno first observed the law of constancy of interfacial angles in quartz crystals in 1669 and this was later generalized and established experimentally by Jean-Baptiste L. Romé de lIslee in 1783. In 1814, Jöns Jacob Berzelius introduced a classification of minerals based on their chemistry rather than their crystal structure, james D. Dana published his first edition of A System of Mineralogy in 1837, and in a later edition introduced a chemical classification that is still the standard. It, however, retains a focus on the structures commonly encountered in rock-forming minerals. An initial step in identifying a mineral is to examine its physical properties and these can be classified into density, measures of mechanical cohesion, macroscopic visual properties, magnetic and electric properties, radioactivity and solubility in hydrogen chloride. If the mineral is crystallized, it will also have a distinctive crystal habit that reflects the crystal structure or internal arrangement of atoms. It is also affected by crystal defects and twinning. Many crystals are polymorphic, having more than one crystal structure depending on factors such as pressure and temperature. ”Examples of polymorphs are calcite and aragonite - two minerals with identical chemical composition, distinguished by their crystallography, calcite is rhombohedral and aragonite is orthorhombic. The crystal structure is the arrangement of atoms in a crystal and it is represented by a lattice of points which repeats a basic pattern, called a unit cell, in three dimensions. The lattice can be characterized by its symmetries and by the dimensions of the unit cell and these dimensions are represented by three Miller indices. The lattice remains unchanged by certain symmetry operations about any point in the lattice, reflection, rotation, inversion, and rotary inversion. Together, they make up an object called a crystallographic point group or crystal class. There are 32 possible crystal classes, in addition, there are operations that displace all the points, translation, screw axis, and glide plane. In combination with the point symmetries, they form 230 possible space groups, most geology departments have X-ray powder diffraction equipment to analyze the crystal structures of minerals. X-rays have wavelengths that are the order of magnitude as the distances between atoms. In a sample that is ground to a powder, the X-rays sample a random distribution of all crystal orientations, powder diffraction can distinguish between minerals that may appear the same in a hand sample, for example quartz and its polymorphs tridymite and cristobalite
8.
Geology
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Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also refer generally to the study of the features of any terrestrial planet. Geology gives insight into the history of the Earth by providing the evidence for plate tectonics, the evolutionary history of life. Geology also plays a role in engineering and is a major academic discipline. The majority of data comes from research on solid Earth materials. These typically fall into one of two categories, rock and unconsolidated material, the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three types of rock, igneous, sedimentary, and metamorphic. The rock cycle is an important concept in geology which illustrates the relationships between three types of rock, and magma. When a rock crystallizes from melt, it is an igneous rock, the sedimentary rock can then be subsequently turned into a metamorphic rock due to heat and pressure and is then weathered, eroded, deposited, and lithified, ultimately becoming a sedimentary rock. Sedimentary rock may also be re-eroded and redeposited, and metamorphic rock may also undergo additional metamorphism, all three types of rocks may be re-melted, when this happens, a new magma is formed, from which an igneous rock may once again crystallize. Geologists also study unlithified material which typically comes from more recent deposits and these materials are superficial deposits which lie above the bedrock. Because of this, the study of material is often known as Quaternary geology. This includes the study of sediment and soils, including studies in geomorphology, sedimentology and this theory is supported by several types of observations, including seafloor spreading, and the global distribution of mountain terrain and seismicity. This coupling between rigid plates moving on the surface of the Earth and the mantle is called plate tectonics. The development of plate tectonics provided a basis for many observations of the solid Earth. Long linear regions of geologic features could be explained as plate boundaries, mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, were explained as divergent boundaries, where two plates move apart. Arcs of volcanoes and earthquakes were explained as convergent boundaries, where one plate subducts under another, transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes. Plate tectonics also provided a mechanism for Alfred Wegeners theory of continental drift and they also provided a driving force for crustal deformation, and a new setting for the observations of structural geology
9.
Well logging
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Well logging, also known as borehole logging is the practice of making a detailed record of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface or on physical measurements made by instruments lowered into the hole. Some types of geophysical well logs can be done during any phase of a history, drilling, completing, producing. Well logging is performed in boreholes drilled for the oil and gas, groundwater, mineral and geothermal exploration, the oil and gas industry uses wireline logging to obtain a continuous record of a formations rock properties. Wireline logging can be defined as being The acquisition and analysis of geophysical data performed as a function of well bore depth, note that wireline logging and mud logging are not the same, yet are closely linked through the integration of the data sets. For this article, they are broken down by the main property that they respond to. Real-time data is recorded directly against measured cable depth, memory data is recorded against time, and then depth data is simultaneously measured against time. The two data sets are then merged using the time base to create an instrument response versus depth log. Memory recorded depth can also be corrected in exactly the way as real-time corrections are made. The measurements made must then be corrected for elastic stretch and temperature, there are many types of wireline logs and they can be categorized either by their function or by the technology that they use. Open hole logs are run before the oil or gas well is lined with pipe or cased, cased hole logs are run after the well is lined with casing or production pipe. Wireline logs can be divided into categories based on the physical properties measured. Conrad and Marcel Schlumberger, who founded Schlumberger Limited in 1926, are considered the inventors of electric well logging, conrad developed the Schlumberger array, which was a technique for prospecting for metal ore deposits, and the brothers adapted that surface technique to subsurface applications. On September 5,1927, a crew working for Schlumberger lowered an electric sonde or tool down a well in Pechelbronn, in modern terms, the first log was a resistivity log that could be described as 3. 5-meter upside-down lateral log. In 1931, Henri George Doll and G. Dechatre, working for Schlumberger and this led to the discovery of the spontaneous potential which was as important as the ability to measure resistivity. The SP effect was produced naturally by the mud at the boundaries of permeable beds. By simultaneously recording SP and resistivity, loggers could distinguish between permeable oil-bearing beds and impermeable nonproducing beds, in 1940, Schlumberger invented the spontaneous potential dipmeter, this instrument allowed the calculation of the dip and direction of the dip of a layer. The basic dipmeter was later enhanced by the resistivity dipmeter and the resistivity dipmeter
10.
Ancient Greek
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Ancient Greek includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD. It is often divided into the Archaic period, Classical period. It is antedated in the second millennium BC by Mycenaean Greek, the language of the Hellenistic phase is known as Koine. Koine is regarded as a historical stage of its own, although in its earliest form it closely resembled Attic Greek. Prior to the Koine period, Greek of the classic and earlier periods included several regional dialects, Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical phases of the language, Ancient Greek was a pluricentric language, divided into many dialects. The main dialect groups are Attic and Ionic, Aeolic, Arcadocypriot, some dialects are found in standardized literary forms used in literature, while others are attested only in inscriptions. There are also several historical forms, homeric Greek is a literary form of Archaic Greek used in the epic poems, the Iliad and Odyssey, and in later poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic, the origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between the divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period and they have the same general outline, but differ in some of the detail. The invasion would not be Dorian unless the invaders had some relationship to the historical Dorians. The invasion is known to have displaced population to the later Attic-Ionic regions, the Greeks of this period believed there were three major divisions of all Greek people—Dorians, Aeolians, and Ionians, each with their own defining and distinctive dialects. Often non-west is called East Greek, Arcadocypriot apparently descended more closely from the Mycenaean Greek of the Bronze Age. Boeotian had come under a strong Northwest Greek influence, and can in some respects be considered a transitional dialect, thessalian likewise had come under Northwest Greek influence, though to a lesser degree. Most of the dialect sub-groups listed above had further subdivisions, generally equivalent to a city-state and its surrounding territory, Doric notably had several intermediate divisions as well, into Island Doric, Southern Peloponnesus Doric, and Northern Peloponnesus Doric. The Lesbian dialect was Aeolic Greek and this dialect slowly replaced most of the older dialects, although Doric dialect has survived in the Tsakonian language, which is spoken in the region of modern Sparta. Doric has also passed down its aorist terminations into most verbs of Demotic Greek, by about the 6th century AD, the Koine had slowly metamorphosized into Medieval Greek
