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Micrinite
Inertinites are a group of partially oxidized organic (mainly plant) materials or fossilized charcoals, all sharing the characteristic that they typically are inert (i.e., not altered) when heated in the absence of oxygen. Inertinite is a common maceral in most types of coal. The main inertinite submacerals are fusinite, semifusinite, micrinite, macrinite, and funginite, with semifusinite being the most common. From the perspective of coal combustion, inertinite can be burned to yield heat but does not yield significant volatile fractions during coking. Inertinite is also found as tiny flakes within sedimentary rocks. The presence of inertinite in this context is significant in the geological record, as it signifies that wildfires may have occurred at the time that the host sediment was deposited. It can also be an indication of oxidation due to atmospheric exposure or fungal decomposition during deposition. The optical properties of semifusinite are very similar to those of vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before prin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charcoal
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen. The material can also be heated in a closed retort. Modern charcoal briquettes used for outdoor cooking may contain many other additives, e.g. coal. The early history of wood charcoal production spans ancient times, rooted in the abundance of wood in various regions. The process typically involves stacking wood billets to form a conical pile, allowing air to enter through openings at the bottom, and igniting the pile gradually. Charcoal burners, skilled professionals tasked with managing the delicate operation, often lived in isolation to tend their wood piles . Throughout histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maceral
A maceral is a component, organic in origin, of coal or oil shale. The term 'maceral' in reference to coal is analogous to the use of the term 'mineral' in reference to igneous or metamorphic rocks. Examples of macerals are inertinite, vitrinite, and liptinite. Inertinite Inertinite is considered to be the equivalent of charcoal and degraded plant material. It is highly oxidised in nature and may be said to be burnt. A large portion of South Africa's coal reserves consist of inertinite. Vitrinite Vitrinite is shiny, glass-like material that is considered to be composed of cellular plant material such as roots, bark, plant stems and tree trunks. Vitrinite macerals when observed under the microscope show a boxlike, cellular structure, often with oblong voids and cavities which are likely the remains of plant stems. This has a high calorific value (24 - 28 MJ/kg) and a large proportion of volatile matter (24 - 30%). It often occurs interbanded or interlaminated with inertini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a type of fossil fuel, formed when dead plant matter decays into peat which is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian (geology), Pennsylvanian) and Permian times. Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution. With the invention of the steam engine, coal consumption increased. In 2020, coal supplied about a quarter of the world's primary energy and over a third of its Electricity generation, electricity. Some iron and steel-maki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusinite
Fusain is a fossilised carbon deposit which, after some controversy, has been identified as fossilised charcoal. It is fibrous, black and opaque, and often preserves details of cell wall architecture. Wood-derived fusain usually takes the form of cubic blocks, whereas fusain from other plant material may take the form of thin films which are only visible under a microscope where the surrounding rock is dissolved by acid maceration. The material is silky and crumbles on the touch. The loss of volatile elements during combustion means that fusain fossils are usually smaller than the original organism, but this same factor makes them unlikely to be eaten by any animals (for they have no nutritional value), enhancing their preservation potential. Fusain shows characteristics diagnostic of pyrolysis Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Funginite
Funginite is a maceral, a component, organic in origin, of coal or oil shale, exhibiting several different physical properties and characteristics under particular conditions; its dimensions are based upon its source and place of discovery. Furthermore, it is primarily part of a group of macerals that naturally occur in rocks containing mostly carbon constituents, specifically coal. Due to its nature, research into the chemical structure and formula of funginite is considered limited and lacking. According to Chen et al. referencing ICCP, 2001 (International Committee for Coal and Organic Petrology), alongside the maceral secretinite, they "are both macerals of the inertinite group, which is more commonly known as fossilized charcoal, and were previously jointly classified as the maceral sclerotinite". In the scientific community, the discernment between the two does not remain entirely clear, but there are slight particular and specific differences in regards to the composition betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coking
Coking is the process of heating coal in the absence of oxygen to a temperature above to drive off the volatile components of the raw coal, leaving behind a hard, strong, porous material with a high carbon content called coke. Coke is predominantly carbon. Its porous structure provides a high surface area, allowing it to burn more rapidly, much like how a bundle of tinder burns faster than a solid wooden log. As such, when a kilogram of coke is burned, it releases more heat than a kilogram of the original coal. Application to smelting iron Coke is used as fuel in a blast furnace. In a continuous process, coke, iron ore, and limestone are mixed together and placed in the top of the blast furnace, and at the bottom liquid iron and waste slag are removed. The raw materials continuously move down the blast furnace. During this continuous process more raw materials are placed at the top, and as the coke moves down, it must withstand the ever-increasing weight of the materials above i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Rock
Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedimentation is any process that causes these particles to settle in place. Geological detritus originates from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or Mass wasting, mass movement, which are called agents of denudation. Biological detritus is formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (marine snow). Sedimentation may also occur when dissolved minerals precipitate from aqueous solution, water solution. The sedimentary rock cover of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire
A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire (Bushfires in Australia, in Australia), desert fire, grass fire, hill fire, Peat#Peat fires, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems Fire ecology, depend on wildfire. Modern forest management often engages in prescribed burns to mitigate fire risk and promote natural forest cycles. However, controlled burns can turn into wildfires by mistake. Wildfires can be classified by cause of ignition, physical properties, combustible material present, and the effect of weather on the fire. Wildfire severity results from a combination of factors such as available fuels, physical setting, and weather. Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sediment
Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension (chemistry), suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone (sedimentary rocks) through lithification. Sediments are most often transported by water (fluvial, fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and stream channel, river channel deposits are examples of fluvial transport and deposition (geology), deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitrinite
Vitrinite is one of the primary components of coals and most sedimentary kerogens. Vitrinite is a type of maceral, where "macerals" are organic components of coal analogous to the "minerals" of rocks. Vitrinite has a shiny appearance resembling glass (vitreous). It is derived from the cell-wall material or woody tissue of the plants from which coal was formed. Chemically, it is composed of polymers, cellulose and lignin. Vitrinite Reflectance (Ro%) : Vitrinite reflectance (Ro%) is a very important geochemical parameter used to assess and evaluate the thermal maturity of sedimentary rocks, particularly those rich in organic matter. It is measure of the reflectivity of vitrinite—a type of maceral (organic component of coal and sedimentary rock)—when viewed under a microscope using oil immersion and reflected light.It is expressed as a percentage (Ro%), vitrinite reflectance increases with greater burial depth and thermal exposure, making it a reliable indicator of the maximum te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflectance
The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic structure of the material to the electromagnetic field of light, and is in general a function of the frequency, or wavelength, of the light, its polarization, and the angle of incidence. The dependence of reflectance on the wavelength is called a ''reflectance spectrum'' or ''spectral reflectance curve''. Mathematical definitions Hemispherical reflectance The ''hemispherical reflectance'' of a surface, denoted , is defined as R = \frac, where is the radiant flux ''reflected'' by that surface and is the radiant flux ''received'' by that surface. Spectral hemispherical reflectance The ''spectral hemispherical reflectance in frequency'' and ''spectral hemispherical reflectance in wavelength'' of a surface, denoted and respectively, are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
