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Topic Review
Chalk
Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). Chalk, as seen in Cretaceous deposits of Western Europe, is unusual among sedimentary limestones in the thickness of the beds. Most cliffs of chalk have very few obvious bedding planes unlike most thick sequences of limestone such as the Carboniferous Limestone or the Jurassic oolitic limestones. This may indicate very stable conditions over tens of millions of years. Chalk has greater resistance to weathering and slumping than the clays with which it is usually associated, thus forming tall, steep cliffs where chalk ridges meet the sea. Chalk hills, known as chalk downland, usually form where bands of chalk reach the surface at an angle, so forming a scarp slope. Because chalk is well jointed it can hold a large volume of ground water, providing a natural reservoir that releases water slowly through dry seasons.
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  • 29 Nov 2022
Topic Review
Oceanic Climate
An oceanic climate, also known as a marine climate or temperate oceanic climate, is the Köppen classification of climate typical of west coasts in higher middle latitudes of continents, and generally features cool summers (relative to their latitude) and cool but not cold winters, with a relatively narrow annual temperature range and few extremes of temperature. Oceanic climates are defined as having a monthly mean temperature below 22 °C (72 °F) in the warmest month, and above 0 °C (32 °F) (or −3 °C (27 °F) in the coldest month). This climate type is often caused by the onshore flow from the cool, high latitude oceans that are found west of their location. It typically lacks a dry season, as precipitation is more evenly dispersed throughout the year. It is the predominant climate type across much of Western Europe, United Kingdom , New Zealand, the Pacific Northwest region of the United States and Canada, far southwestern South America, a narrow zone of southeastern Australia including Tasmania, and isolated locations elsewhere. Oceanic climates are generally characterised by a narrower annual range of temperatures than in other places at a comparable latitude, and generally do not have the extremely dry summers of Mediterranean climates or the hot and wet summers of humid subtropical climates. Oceanic climates are most dominant in Europe, where they spread much farther inland than in other continents. Oceanic climates can have considerable storm activity as they are located in the belt of the stormy westerlies. Many oceanic climates have frequent cloudy or overcast conditions due to the near constant storms and lows tracking over or near them. The annual range of temperatures is smaller than typical climates at these latitudes due to the constant stable marine air masses that pass through oceanic climates, which lack both very warm and very cool fronts.
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Topic Review
Effects of Global Warming on Oceans
Effects of global warming on oceans provides information on the various effects that global warming has on oceans. Global warming can affect sea levels, coastlines, ocean acidification, ocean currents, seawater, sea surface temperatures, tides, the sea floor, weather, and trigger several changes in ocean bio-geochemistry; all of these affect the functioning of a society.
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Topic Review
List of Minerals F (Complete)
This list includes those recognised minerals beginning with the letter F. 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).
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Topic Review
Trewartha Climate Classification
The Trewartha climate classification is a climate classification system first published by American geographer Glenn Thomas Trewartha in 1966. It is a modified version of the Köppen-Geiger system, created to answer some of its deficiencies. The Trewartha system attempts to redefine the middle latitudes to be closer to vegetation zoning and genetic climate systems. It was considered a more true or "real world" reflection of the global climate. The changes were seen as most effective on the large landmasses in Asia and North America, where many areas fall into a single group (C) in the Köppen-Geiger system. For example, under the standard Köppen system, Washington (state) and Oregon are classed into the same climate zone (Csb) as Southern California, even though the two regions have strikingly different weather and vegetation. Another example was classifying cities like London in the same climate group (C) as Brisbane or New Orleans, despite great differences in seasonal temperatures and native plant life.
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Topic Review
Coal Fly Ash Production, Utilization in India
Coal fly ash (CFA) is one of the most burning issues in the whole world due to its large amount of production in thermal power plants. Every year a million tons (MTs) of CFA are generated globally of which almost half is utilized in various forms, while the remaining half remains unused, leading to various types of pollution.
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Topic Review
EcoHealth
EcoHealth (also referred to as Health Ecology) is an emerging field of study researching how changes in the earth’s ecosystems affect human health. It has many prospects. EcoHealth examines changes in the biological, physical, social and economic environments and relates these changes to human health. Examples of these changes and their effects abound. Common examples include increases in asthma rates due to air pollution, PCB contamination of game fish in the Great Lakes of the United States , and habitat fragmentation leading to increasing rates of Lyme disease. Recently virulent new infectious diseases such as SARS, Ebola virus, Nipah virus, bird flu and hantavirus have all been found to result from ecosystem change created by humans. These diseases have high death rates and very few effective therapies. EcoHealth is bringing together physicians, veterinarians, ecologists, life scientists, social scientists, agricultural scientists, landscape and urban planners, and others to study how ecosystem changes affect human health. EcoHealth strives to provide innovative, practical solutions to reduce or reverse the negative health effects of ecosystem change, and to use the salutogenic effects of functional ecosystems to improve public health.
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Topic Review
Stadt Huys Site
The Stadt Huys (an old Dutch spelling, meaning city hall) was the very first city hall in New York City built in 17th-century during Dutch settlement (New Amsterdam). It stopped function in 1679 due to safety. It is located at the 71 Pearl Street today. The Stadt Huys block archaeology project was the first large scale archaeological excavation in New York City in 1979-1980. At the time it was excavated, it was one of the most expensive and most productive projects of urban archeology undertaken in an American city. A lot of logistical procedures for urban archaeology had to be developed as the project evolved. Most of these procedures have become a model for performing large-scale excavations in the city.
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Topic Review
Struthiosaurinae
Struthiosaurinae is a subfamily of ankylosaurian dinosaurs from the Cretaceous of Europe. It is defined as "the most inclusive clade containing Europelta but not the North American Cedarpelta, Peloroplites, Sauropelta or Edmontonia" while being reinstated for a newly recognized clade of basal nodosaurids. Struthiosaurinae appeared at about exactly the same time as the North American subfamily Nodosaurinae. Struthiosaurines range all across the Cretaceous, the oldest genus being Europelta at an age of 112 Ma and the youngest being Struthiosaurus at about 85–66 Ma. It was originally mentioned by Franz Nopcsa in 1923 as a subfamily of Acanthopholidae, along with the previously defined Acanthopholinae. The family has gone through many taxonomic revisions since it was defined by Nopcsa in 1902. It is now recognized as a junior synonym of the family Nodosauridae. The subfamily now includes the genera Anoplosaurus, Europelta, Hungarosaurus, and Struthiosaurus, designated as the type genus. Because of the instability of Acanthopholis, the generic namesake of Acanthopholinae, and its current identification as a nomen dubium, Struthiosaurinae, the next named group, was decidedly used over the older one. A review of ankylosaur osteoderms was published in 2000, and reviewed the armour of Struthiosaurinae. The group was represented by the single genus Struthiosaurus, known from head, cervical, dorsal, sacral, and caudal scutes. Only a few head osteoderms were identified, so it is unknown how much of the skull was armoured. Many cervical and dorsal scutes have been preserved alongside species of Struthiosaurus. They include cervical bands, which are groups of osteoderms fused together and attached to the vertebrae, and large spines found on the shoulders of nodosaurids like Sauropelta and Edmontonia, although it is not known if the spines were fused like the later of separate like the former. It is quite possible that small ovoid scutes found on Struthiosaurus could have formed a pelvic shield like polacanthids. The caudal scutes of struthiosaurines are small and rough. Even though osteoderms are well-known, it is not certain where they were positioned on the body.
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Topic Review
Bread in Culture
Bread has a significance beyond mere nutrition in many cultures in the Western world and Greater Middle East because of its history and contemporary importance. Bread is also significant in Christianity as one of the elements (alongside wine) of the Eucharist; see sacramental bread. The word companion comes from Latin com- "with" + panis "bread". The political significance of bread is considerable. In 19th century Britain, the inflated price of bread due to the Corn Laws caused major political and social divisions, and was central to debates over free trade versus protectionism. The Assize of Bread and Ale in the 13th century demonstrated the importance of bread in medieval times by setting heavy punishments for short-changing bakers, and bread appeared in Magna Carta a half-century earlier. Like other foods, choosing the "right" kind of bread is used as a social signal, to let others know, for example, that the person buying expensive bread is financially secure, or the person buying whatever type of bread that the current fashions deem most healthful is a health-conscious consumer. As a simple, cheap, and adaptable type of food, bread is often used as a synecdoche for food in general in some languages and dialects, such as Greek and Punjabi. There are many variations on the basic recipe of bread worldwide, such as bagels, baguettes, biscuits, bocadillo, brioche, chapatis, Challah, lavash, naan, pitas, pizza, pretzels, puris, tortillas, and many others. There are various types of traditional "cheese breads" in many countries, including Brazil , Colombia, Italy, and Russia .
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