Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Amin Beiranvand Pour
My scholarly interests range widely, from mineral exploration to environmental issues such as geo-hazard, structural mapping, geothermal and geomorphic and coastal geology investigations. Subsequently, I have conducted several research projects for geological mapping, disaster management and environmental modeling using a variety of satellite remote sensing data such as the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Landsat Enhanced Thematic Mapper+ (ETM+), Landsat-8, Advanced Land Imager (ALI), Hyperion and Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite data in arid and semi-arid terrains, Antarctic, Arctic and tropical environments. 
  • 1.2K
  • 10 Nov 2020
Topic Review
Pyrolysis of Technogenic-Redeposited Coal-Bearing Rocks
Hydrocarbon products formed under high-temperature and low-temperature pyrolysis of coal-bearing rocks were studied by using a chromatography-mass spectrometer GCMS-QP2010NC Plus (made by Shimadzu Company). The average temperature of low-temperature natural pyrolysis does not exceed 120°C, and its average speed is approximately 2 m/year. In this case, three pyrolysis zones gradually built metamorphic rock mass (from bottom to top) are clearly established: heating (focal) activated and enriched. The average temperature of high-temperature pyrolysis reaches 850°C, and its average speed is approximately 20 m/year. Unlike low-temperature pyrolysis, high-temperature pyrolysis is accompanied by the presence of two major zones (from bottom to top): pyrogenic (focal) and enriched (coke). The chemical composition of the enriched pyrolysis zone was studied in detail. It has been established that hydrocarbon compounds in samples of the pyrolysis zone are presented by six classes: asphaltic-resinous substances; polycyclic aromatic hydrocarbons, heterocyclic compounds, organic sulphur compounds; pyrolytic hydrocarbon and heavy hydrocarbon residue. Quantitative content of hydrocarbon compounds in the analyzed samples varies from 0.35% to 41.88%.   Based on the materials of fieldwork, we created a video film that can be seen on the website https://youtu.be/Tqs6YiKfDdE
  • 1.2K
  • 29 Oct 2020
Topic Review
Application of Nanomaterials in Enhanced Oil Recovery
The implementation of nanoparticles in Enhanced Oil Recovery (EOR) techniques is a novel method that has proven to increase the recovery of oil in place more than conventional EOR processes in most cases. The main aim of integrating nanoparticles in EOR methods is to boost the performance of each EOR technique by enhancing one or more parameters or mechanisms related to the recovery method. Sometimes, adding nanoparticles to the EOR method might reduce oil recovery due to porosity reduction, injection blockage, aggregation, and settling problems. The utilization of nanomaterials in several EOR applications comes with many benefits, such as IFT reduction, wettability alteration, and mobility improvement.
  • 1.2K
  • 02 Feb 2023
Topic Review
Tectonic Archaeology
Tectonic Archaeology is conceived as an umbrella term for efforts to deal with evidence of volcanic eruptions, earthquakes, and tsunami in the archaeological record and the consequences for society. It also can serve as a foundation for Geoarchaeology in general.
  • 1.1K
  • 28 Sep 2021
Topic Review
Sierra Espuña Cenozoic Malaguide Basin
The Cenozoic Malaguide Basin from Sierra Espuña (Internal Betic Zone, S Spain) due to the qual-ity of outcropping, areal representation, and continuity in the sedimentation can be considered a key-basin. In the last 30 years, a large number of studies with very different methodological ap-proaches have been done in the area. Models indicate an evolution from passive margin to wedge-top basin from Late Cretaceous to Early Miocene. Sedimentation changes from limestone platforms with scarce terrigenous inputs, during the Paleocene to Early Oligocene, to the deep ba-sin with huge supplies of turbidite sandstones and conglomerates during the Late Oligocene to Early Miocene. The area now appears structured as an antiformal stack with evidence of synsedimentary tectonics.
  • 1.1K
  • 19 Jan 2021
Topic Review
Coastal Adaptation to Sea-Level Rise
The Earth’s climate is changing; ice sheets and glaciers are melting and coastal hazards and sea level are rising in response. With a total population of over 300 million people situated on coasts, including 20 of the planet’s 33 megacities (over 10 million people), low-lying coastal areas represent one of the most vulnerable areas to the impacts of climate change. The need to identify and implement adaptation solutions to the impacts of climate change in coastal zones is urgent. 
  • 1.1K
  • 17 Aug 2021
Topic Review
Pedro JM Costa
My research focus on the study of coastal processes using geomorphological and sedimentological data coupled with physical and numerical modeling to understand morphological and sediment changes caused by natural hazards (e.g. tsunamis and storms) and their impacts on the environment. I also work on the establishment of provenance relationships in siliciclastic sediments, aspects of aeolian sediment transport, Antarctic soils, Mars geology and geoarchaeological studies.
  • 1.1K
  • 10 Nov 2020
Topic Review
Mining Effects on the Karst
Karst develops on soluble rocks (limestone, dolomite, and evaporite). The infiltrating water with carbonic acid creates cavities (caves), fills them, and flows towards the mountain margin (karst water), where it emerges in springs. The infiltrated water constitutes a three-dimensional system whose surface is the karst water level, which undergoes fluctuation of various degrees and periods due to natural and artificial effects, at another time a one-way rise or subsidence. Since karst rocks drain water, neither a surface water network nor valleys develop (they are only formed at sites where the valley is inherited from the non-karstic cover or when the karst water level is situated at the valley floor). The dissolved material is transported into the karst with the infiltrating waters; therefore, surface karst features are closed. These are karren, dolines, ponors with blind valleys, and poljes. The material transported in the solution precipitates as freshwater limestone.
  • 1.1K
  • 05 Dec 2022
Topic Review
List of Minerals Approved by IMA (P–Q)
This list includes those recognised minerals beginning with the letters P and Q. The International Mineralogical Association is the international group that recognises new minerals and new mineral names, however minerals discovered before 1959 did not go through the official naming procedure, although some minerals published previously have been either confirmed or discredited since that date. This list contains a mixture of mineral names that have been approved since 1959 and those mineral names believed to still refer to valid mineral species (these are called "grandfathered" species). The list is divided into groups: The data was exported from mindat.org on 29 April 2005; updated up to 'IMA2018'. The minerals are sorted by name, followed by the structural group (rruff.info/ima and ima-cnmnc by mineralienatlas.de, mainly) or chemical class (mindat.org and basics), the year of publication (if it's before of an IMA approval procedure), the IMA approval and the Nickel–Strunz code. The first link is to mindat.org, the second link is to webmineral.com, and the third is to the Handbook of Mineralogy (Mineralogical Society of America).
  • 1.1K
  • 06 Nov 2022
Topic Review
Core-Mantle Differentiation
Core-mantle differentiation is the set of processes that took place during the accretion stage of Earth's evolution (or more generally, of rocky planets) that results in the separation of iron-rich materials that eventually would conform a metal core, surrounded by a rocky mantle. According to the Safronov's model, protoplanets formed as the result of collisions of smaller bodies (planetesimals), which previously condensed from solid debris present in the original nebula. Planetesimals contained iron and silicates either already differentiated or mixed together. Either way, after impacting the Proto-Earth their materials very likely became homogenized. At this stage, the Proto-Earth was probably the size of Mars. Next followed the separation and stratification of the Proto-Earth's constituents, chiefly driven by their density contrasts. Factors such as pressure, temperature, and impact bodies in the primordial magma ocean have been involved in the differentiation process. The differentiation process is driven by the higher density of iron compared to silicate rocks, but the lower melting point of the former constitutes an important factor. In fact, once iron has melted, differentiation can take place whether silicate rocks are completely melted or not. On the premises of these plausible scenarios, several models have been proposed to account for the core-mantle differentiation following the stage of nebular formation of the solar system. They can be summarized into three mechanisms: 1) Percolation of iron alloy through silicate crystals; 2) Separation of metal from rock in a primordial magma ocean; 3) Migration of iron diapirs or dikes through the mantle.
  • 1.1K
  • 08 Nov 2022
Topic Review
Bradoriids and the Cambrian Diversification
Bradoriids, among the earliest arthropods to appear in the fossil record, are extinct, ostracod-like bivalved forms that ranged from the early Cambrian to the Middle Ordovician. Bradoriids are notable for having appeared in the Cambrian fossil record before the earliest trilobites, and considering their rapid ascent to high genus-level diversity, provide key data for our understanding of the evolutionary dynamics of the Cambrian Explosion. This paper presents a broad review of bradoriid paleobiology. 
  • 1.1K
  • 29 Oct 2020
Topic Review
Japan Median Tectonic Line
Japan Median Tectonic Line (中央構造線, Chūō Kōzō Sen), also Median Tectonic Line (MTL), is Japan's longest fault system. The MTL begins near Ibaraki Prefecture, where it connects with the Itoigawa-Shizuoka Tectonic Line (ISTL) and the Fossa Magna. It runs parallel to Japan's volcanic arc, passing through central Honshū to near Nagoya, through Mikawa Bay, then through the Inland Sea from the Kii Channel and Naruto Strait to Shikoku along the Sadamisaki Peninsula and the Bungo Channel and Hōyo Strait to Kyūshū. The sense of motion on the MTL is right-lateral strike-slip, at a rate of about 5–10 mm/yr. This sense of motion is consistent with the direction of oblique convergence at the Nankai Trough. The rate of motion on the MTL is much less than the rate of convergence at the plate boundary, making it difficult to distinguish the motion on the MTL from interseismic elastic straining in GPS data.
  • 1.1K
  • 10 Nov 2022
Topic Review
Tungsten in Soil
Tungsten (W) occurs naturally in soils and the Earth’s crust is the most important source of this element. Tungsten reserves have been estimated to be approximately 3.1 Mt in ore deposits, where the metal exists mainly as a component of several minerals, such as wolframite (Fe, MnWO4) and scheelite (CaWO4).
  • 1.1K
  • 26 Jul 2021
Topic Review
Groundwater Temperature Measurements
Groundwater temperature (GWT) can be influenced by anthropogenic factors such as surface sealing or geothermal use. These thermal influences can lead to geochemical changes in groundwater, which can affect groundwater quality. Therefore, it is important to measure and monitor GWT. For this purpose, screened monitoring wells (MWs) are usually used. However, temperature measurements can be disturbed by vertical currents within MWs as a result of convection.
  • 1.1K
  • 05 May 2022
Topic Review
Geodiversity and Geoconservation in Central America
Central America is located in a dynamic region where tectonics and volcanism together with the tropical climate and its diverse vegetation have shaped the landscapes. 
  • 1.0K
  • 06 Jan 2022
Topic Review
Porphyry Mo Deposits
Porphyry Mo deposits are the most important type of Mo resource. They result from a high oxygen fugacity of the parent magma, which acts as an effective indicator for evaluating the mineralization. In the ore-forming system of porphyry Mo deposits, sulfur exists mainly as sulfate in highly oxidized magma but as sulfide in ores. What triggers the reduction in the mineralization system that leads to sulfide precipitation has not yet been determined. 
  • 1.0K
  • 28 Jul 2023
Topic Review
Polar Forests of the Cretaceous
Cretaceous polar forests were temperate forests that grew at polar latitudes during the final period of the Mesozoic Era, known as the Cretaceous Period 145–66 Ma. During this period, global average temperature was about 10 °C (18 °F) higher and carbon dioxide (CO2) levels were approximately 1000 parts per million (ppm), 2.5 times the current concentration in Earth's atmosphere. The abundance of atmospheric carbon dioxide had a very significant impact on global climate and Earth's natural systems as its concentration is considered one of the main factors in the development of a pronounced greenhouse Earth during the Cretaceous with a very low average global temperature gradient. As a consequence, high paleolatitudes in both hemispheres were much warmer than at present. This temperature gradient was partly responsible for the lack of continental ice sheets in polar regions. As a response to elevated global temperatures, the Earth's hydrologic cycle was significantly enhanced due to greater volume of moisture evaporation from the surface of the ocean. In turn, the absolute sea level during this time period stood at elevations much higher than the present level. Continental encroachment of seawater formed widespread shallow seas, including expanses of epeiric seas. An increase in surface area between shallow, warm epeiric seawater and the atmosphere permits higher evaporation rates and more precipitation at various latitudes, producing a more temperate global climate. A widespread temperate climate also had significant effects on high latitude ecosystems.
  • 1.0K
  • 02 Nov 2022
Topic Review
Diamond-Bearing Ophiolite
Ophiolites are fragments of ancient oceanic crust and upper mantle, which is created at ocean spreading ridges and then emplaced on land. Ophiolite-hosted diamond discovered in ophiolitic peridotite and chromitite is considered to be a new type that has been named an ophiolite-type by Yang et al., in 2011. 
  • 973
  • 22 Nov 2021
Topic Review
Geochemical Characteristics of Oceanic Carbonatites
The occurrence of carbonatites in oceanic settings is very rare if compared with their continental counterpart, having been reported only in Cape Verde and Canary Islands. This entry provides an overview of the main geochemical characteristics of oceanic carbonatites, around which many debates still exist regarding their petrogenesis.
  • 965
  • 26 Mar 2021
Topic Review
Geologic Background of Sixtymile Gold District, Yukon, Canada
The Sixtymile gold district, Yukon, Canada has been mined for placer gold since the late 19th century. 
  • 961
  • 14 Apr 2022
  • Page
  • of
  • 6
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Video Production Service
Feedback