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Topic Review

Jáchymov (Czech pronunciation: [ˈjaːxɪmof]); German: Sankt Joachimsthal or Joachimsthal) is a spa town in Karlovy Vary District in the Karlovy Vary Region of the Czech Republic. It has about 2,300 inhabitants. The historical core of the town from the 16th century is well preserved and protected by law as urban monument zone. It is a comprehensive set of Gothic–Renaissance patrician houses. Jáchymov has a long mining tradition, thanks to which it used to be the second most populous town in the Kingdom of Bohemia in 1534. At first silver was mined here. The silver Joachimsthaler coins minted here since the 16th century gave their name to the Thaler and the dollar. After the Wieliczka Salt Mine ceased industrial exploitation in 2007, the Svornost mine (1525) became the oldest mine still in use in Europe. It is also the first and for a long time the only mine in the world, where radium was mined. The mining cultural landscape of Jáchymov is a UNESCO World Heritage Site as a part of the Ore Mountain Mining Region.

3.3K
04 Nov 2022

Topic Review

Geology (from grc γῆ 'earth', and -λoγία 'study of, discourse') is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology and the atmospheric sciences, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, and numerical modelling. In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and providing insights into past climate change. Geology is a major academic discipline, and it is central to geological engineering and plays an important role in geotechnical engineering.

3.1K
27 Nov 2022

Topic Review

Antimony as a Critical Raw Material

Antimony is widely acknowledged as a critical raw material of worldwide significance, based on its recognition by many countries. According to current projections, there is an anticipated increase in the demand for antimony in the forthcoming years. An issue of significant concern within the supply chain, which poses a substantial obstacle to sustainable development, is the global unequal allocation of abundant antimony resources. Most nations exhibited a high degree of dependence on a few countries for their net imports of antimony, resulting in a notable disruption and raising concerns regarding the supply chain.

3.1K
23 Feb 2024

Topic Review

List of Minerals Approved by IMA (T)

This list includes those recognised minerals beginning with the letter T. 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 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.

3.0K
09 Oct 2022

Topic Review

May 29: First Successful Ascent of Mount Everest

On May 29, 1953, New Zealand mountaineer Edmund Hillary (later knighted) and Nepali Sherpa Tenzing Norgay became the first confirmed climbers to reach the 8,848-meter summit of Mount Everest as part of the ninth British expedition led by John Hunt (later Lord Hunt). Their successful ascent via the Southeast Ridge route (using the South Col as a high camp) marked the culmination of 30 years of British attempts on the mountain. The news reached Britain on June 2, coinciding with Queen Elizabeth II's coronation. Hillary was knighted and Norgay received the George Medal, with their achievement revolutionizing high-altitude mountaineering.

2.9K
27 May 2025

Topic Review

Antigorite is a Mg-rich 1:1 trioctahedral-structured layered silicate mineral of the serpentine group. Antigorite with layered structure can be used as a lubricant and friction reducing material to repair the friction pair of iron agent on line.

2.8K
26 Oct 2020

Biography

Barry Voight (/vɔɪt/; born 1937) is an American geologist, volcanologist, author, and engineer. After earning his Ph.D. at Columbia University, Voight worked as a professor of geology at several universities, including Pennsylvania State University, where he taught from 1964 until his retirement in 2005. He remains an emeritus professor there and still conducts research, focusing on rock mecha

2.7K
30 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).

2.6K
06 Nov 2022

Topic Review

Appalachia (Mesozoic)

During most of the Late Cretaceous (100.5 to 66 million years ago) the eastern half of North America formed Appalachia (named for the Appalachian Mountains), an island land mass separated from Laramidia to the west by the Western Interior Seaway. This seaway had split North America into two massive landmasses due to a multitude of factors such as tectonism and sea-level fluctuations for nearly 40 million years. seaway eventually exapanded, divided across the Dakotas, and by the end of the Cretaceous, it retreated towards the Gulf of Mexico and the Hudson Bay. This left the island masses joined in the continent of North America as the Rocky Mountains rose. From the Cenomanian to the end of the Campanian ages of the Late Cretaceous, Appalachia was separated from the rest of North America. As the Western Interior Seaway retreated in the Maastrichtian, Laramidia and Appalachia eventually connected. Because of this, its fauna was isolated, and developed very differently from the tyrannosaur, ceratopsian, hadrosaurid, pachycephalosaur and ankylosaurid dominated fauna of the western part of North America, known as "Laramidia". Due to the fact that Appalachia was largely flat and had less erosion compared to Laramidia, no terrestrially formed deposits have survived, with most dinosaur remains originating from seaborne carcasses that were transported into marine environments. Some sediments have been removed by glacial erosion during the last ice age, but it is difficult to ascertain how much sediment has been removed, or whether these sediments would have been any more productive than those that remain. Thus relatively little is known about Appalachia in comparison to Laramidia, with exception of plant life, marine life and the insects trapped in amber from New Jersey. In addition, due to a lack of interest in Appalachia, many fossils that have been found in Appalachia lie unstudied and remain in the inaccurate genera to which they were assigned in the days of E. D. Cope and O. C. Marsh. Only a few fossils of the terrestrial creatures that were found in this region have given us a brief glimpse into what life was like here during the Cretaceous period. However, the area has seen a bit of a resurgence of interest due to several discoveries made in the past few years. As mentioned earlier, not much is known about Appalachia, but some fossil sites, such as the Woodbine Formation, Navesink Formation, Ellisdale Fossil Site, Mooreville Chalk Formation, Demopolis Chalk Formation, Black Creek Group and the Niobrara Formation, together with ongoing research in the area, have given us a better look into this forgotten world of paleontology.

2.4K
17 Oct 2022

Topic Review

Saltwater lakes around the world are drying at a rapid rate. These lakes are present in arid and semi-arid regions where evaporation exceeds precipitation. The Aral Sea and Lake Urmia are examples for such rapidly drying lakes. These two lakes have lost up to 90% of their former area in the past 50 years.

2.3K
28 Oct 2020

Topic Review

Marine Nepheloid Layer

Marine nepheloid layer is a turbid layer containing significantly more suspended particles than the adjacent layers in oceans. The suspended particles may collide and form large falling particle aggregates known as marine snow. Although the nepheloid layer continually changes with time and space, it shows certain temporal and spatial stability. A marine nepheloid layer could last a few days to years, with a thickness ranging from meters to kilometers.

2.3K
16 Mar 2022

Topic Review

Expert System for Earthquake Prediction

Earthquake is one of the most hazardous natural calamity. Many algorithms have been proposed for earthquake prediction using expert systems (ES). We aim to identify and compare methods, models, frameworks, and tools used to forecast earthquakes using different parameters. The analysis shows that most of the proposed models have attempted long term predictions about time, intensity, and location of future earthquakes. An investigation on different variants of rule-based, fuzzy, and machine learning based expert systems for earthquake prediction has been presented. Moreover, the discussion covers regional and global seismic data sets used, tools employed, to predict earth quake for different geographical regions. Bibliometric and meta-information based analysis has been performed by classifying the articles according to research type, empirical type, approach, target area, and system specific parameters.

2.2K
03 Feb 2021

Topic Review

Impact of High-Temperature Treatment on Granite

Temperature changes have significant effects on rock properties. The changes in properties vary for different rocks with different temperature ranges. Granite is an igneous type of rock that is common in India and is frequently used for construction and domestic purposes. Granite is mainly composed of quartz and feldspar and shows a considerable response to temperature changes. The heating effects of granite on its physical and mechanical properties become increasingly pronounced with increasing pick temperatures.

2.2K
29 Nov 2022

Topic Review

Agate ‒ a spectacular form of SiO2 and a famous gemstone ‒ is commonly characterized as banded chalcedony. In detail, chalcedony layers in agates can be intergrown or intercalated with macro-crystalline quartz, quartzine, opal-C, opal-CT, cristobalite and/or moganite. In addition, agates often contain considerable amounts of mineral inclusions and water as both interstitial molecular H2O and silanol groups.

2.1K
16 Apr 2021

Topic Review

"Zorbas" on Southeastern Sicily

Over the last few years, several authors have presented contrasting models to describe the response of boulders to extreme waves, but the absence of direct observation of movements has hindered the evaluation of these models. The recent development of online video-sharing platforms in coastal settings has provided the opportunity to monitor the evolution of rocky coastlines during storm events. In September 2018, a surveillance camera of the Marine Protected Area of Plemmirio recorded the movement of several boulders along the coast of Maddalena Peninsula (Siracusa, Southeastern Sicily) during the landfall of the Mediterranean tropical-like cyclone (Medicane) Zorbas. Unmanned autonomous vehicle (UAV) photogrammetric and terrestrial laser scanner (TLS) surveys were performed to reconstruct immersive virtual scenarios to geometrically analyze the boulder displacements recorded in the video. Analyses highlighted that the displacements occurred when the boulders were submerged as a result of the impact of multiple small waves rather than due to a single large wave. Comparison between flow velocities obtained by videos and calculated through relationships showed a strong overestimation of the models, suggesting that values of flow density and lift coefficient used in literature are underestimated.

2.1K
25 Aug 2021

Topic Review

Applications of DAS in Linear Infrastructure Monitoring

Linear infrastructures, such as railways, tunnels, and pipelines, play essential roles in economic and social development worldwide. Distributed acoustic sensing (DAS) is an emerging sensing technology that has rapidly developed in recent years. Due to its unique advantages in long-distance, high-density, and real-time monitoring, DAS arrays have shown broad application prospects in many fields, such as oil and gas exploration, seismic observation, and subsurface imaging. In the field of linear infrastructure monitoring, DAS has gradually attracted the attention of researchers and practitioners.

2.1K
01 Dec 2022

Topic Review

Water Footprint

The water footprint (WF) is a widely recognised and comprehensive indicator of both the direct and indirect appropriation of freshwater. It has been utilised for diverse functions, including as a key indicator of the planetary boundaries and United Nations Sustainable Development Goals. (draft for definition)

2.0K
03 Feb 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.

2.0K
28 Jul 2023

Topic Review

List of Minerals Approved by IMA (E)

This list includes those recognised minerals beginning with the letter E. 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).

1.9K
20 Oct 2022

Topic Review

A crystal mush is a magmatic body which contains a significant amount of crystals (up to 50% of the volume) suspended in the liquid phase (melt). As the crystal fraction makes up less than half of the volume, there is no rigid large-scale three-dimensional network as in solids. As such, their rheological behavior mirrors that of absolute liquids. Within a single crystal mush, there is grading to a higher solid fraction towards the margins of the pluton while the liquid fraction increases towards the uppermost portions, forming a liquid lens at the top. Furthermore, depending on depth of placement crystal mushes are likely to contain a larger portion of crystals at greater depth in the crust than at shallower depth, as melting occurs from the adiabatic decompression of the magma as it rises, this is particularly the case for mid-oceanic ridges. Seismic investigation offers strong evidence for the existence of crystal mushes rather than fully liquid magmatic bodies. Crystal mushes can have a wide range of chemical and mineralogical compositions, from mafic (SiO2-poor, MgO-rich) to felsic (SiO2-rich, MgO-poor).

1.9K
01 Dec 2022

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