Chalk
Chalk ( /ˈtʃɔːk/) is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. 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
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
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Coordinates: 51°N 9°E / 51°N 9°E / 51; 9Federal Republic
Republic of Germany Bundesrepublik Deutschland (German)[a]FlagCoat of armsMotto: "Einigkeit und Recht und Freiheit" (de facto) "Unity and Justice and Freedom"Anthem: "Deutschlandlied" (third verse only)[b] "Song of Germany"Location of Germany (dark green) – in Europe (green & dark grey) – in the European Union (green)Location of
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Groundwater
Groundwater is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater
Groundwater is recharged from, and eventually flows to, the surface naturally; natural discharge often occurs at springs and seeps, and can form oases or wetlands. Groundwater
Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells
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In geology, petrifaction or petrification is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood
Petrified wood typifies this process, but all organisms, from bacteria to vertebrates, can become petrified (although harder, more durable matter such as bone, beaks, and shells survive the process better than softer remains such as muscle tissue, feathers, or skin). Petrifaction
Petrifaction takes place through a combination of two similar processes: permineralization and replacement
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The Negev (Hebrew: הַנֶּגֶב, Tiberian vocalization: han-Néḡeḇ ; Arabic: النقب an-Naqab) is a desert and semidesert region of southern Israel. The region's largest city and administrative capital is Beersheba (pop. 205,810), in the north. At its southern end is the Gulf of Aqaba and the resort city of Eilat. It contains several development towns, including Dimona, Arad and Mitzpe Ramon, as well as a number of small Bedouin cities, including Rahat and Tel as-Sabi and Lakyah
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Coordinates: 31°N 35°E / 31°N 35°E / 31; 35State of Israelמְדִינַת יִשְׂרָאֵל (Hebrew) دَوْلَة إِسْرَائِيل (Arabic)FlagEmblemAnthem: "Hatikvah" (Hebrew for "The Hope")(pre-) 1967 border (Green Line)Capital and largest city Jerusalem
Jerusalem (limited recognition)[fn 1] 31°47′N 35°13′E / 31.783°N 35.217°E / 31.783; 35.217Official languagesHebrew ArabicEthnic groups (2017)74.7% Jewish
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The Mesozoic
Mesozoic Era ( /ˌmɛsəˈzoʊɪk, ˌmiː-, -soʊ-/ or /ˌmɛzəˈzoʊɪk, ˌmiː-, -soʊ-/[1][2]) is an interval of geological time from about 252 to 66 million years ago. It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell
Gideon Mantell who viewed it as dominated by diapsids such as Iguanodon, Megalosaurus, Plesiosaurus
Plesiosaurus and Pterodactylus. This Era is also called from a paleobotanist view the Age of Conifers.[3] Mesozoic
Mesozoic means "middle life", deriving from the Greek prefix meso-/μεσο- for "between" and zōon/ζῷον meaning "animal" or "living being".[4] It is one of three geologic eras of the Phanerozoic Eon, preceded by the Paleozoic
Paleozoic ("ancient life") and succeeded by the Cenozoic
Cenozoic ("new life")
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Clay
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Clay is a finely-grained natural rock or soil material that combines one or more clay minerals with possible traces of quartz (SiO4), metal oxides (Al2O3 , MgO etc.) and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Clays are plastic due to particle size and geometry as well as water content, and become hard, brittle and non–plastic upon drying or firing.[1][2][3] Depending on the soil's content in which it is found, clay can appear in various colours from white to dull grey or brown to deep orange-red.Electron microscope photograph of smectite clay – magnification 23,500Although many naturally occurring deposits include both silts and clay, clays are distinguished from other fine-grained soils by differences in size and mineralogy
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A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit (e.g. Box Hill, Surrey).Contents1 Terminology 2 Historical significance 3 Military significance 4 Sports and games 5 Largest man-made 6 Gallery 7 See also 8 References 9 External linksTerminology[edit] Chocolate Hills
Chocolate Hills of the PhilippinesHills in Tuscany, ItalyThe distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally considered to be less tall and less steep than a mountain. In the United Kingdom, geographers historically regarded mountains as hills greater than 1,000 feet (304.8 meters) above sea level, which formed the basis of the plot of the 1995 film The Englishman Who Went Up a Hill
Hill But Came Down a Mountain
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1 French Land Register data, which excludes lakes, ponds, glaciers > 1 km2 (0.386 sq mi or 247 acres) and river estuaries. 2 Population without double counting: residents of multiple communes (e.g., students and military personnel) only counted once. Meudon
Meudon (French pronunciation: [mø.dɔ̃]) is a municipality in the southwestern suburbs of Paris, France. It is in the département of Hauts-de-Seine
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A fossil (from Classical Latin
Latin fossilis; literally, "obtained by digging")[1] 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, hair, petrified wood, oil, coal, and DNA
DNA remnants. The totality of fossils is known as the fossil record. Paleontology
Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old.[2] The oldest fossils are from around 3.48 billion years old[3][4][5] to 4.1 billion years old.[6][7] The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils
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Underground hard rock mining refers to various underground mining techniques used to excavate hard minerals, usually those containing metals[1] such as ore containing gold, silver, iron, copper, zinc, nickel, tin and lead, but also involves using the same techniques for excavating ores of gems such as diamonds. Soft rock mining refers to excavation of softer minerals such as salt, coal, or oil sands.Contents1 Mine access1.1 Underground access 1.2 Ore
Ore access2 Development mining vs. production mining 3 Ventilation 4 Ground support4.1 Area ground support4.1.1 Mechanical bolts 4.1.2 Grouted bolts 4.1.3 Friction bolts4.2 Local ground support5 Stope and retreat vs
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The Industrial Revolution
Industrial Revolution was the transition to new manufacturing processes in the period from about 1760 to sometime between 1820 and 1840. This transition included going from hand production methods to machines, new chemical manufacturing and iron production processes, the increasing use of steam power, the development of machine tools and the rise of the factory system. Textiles were the dominant industry of the Industrial Revolution
Industrial Revolution in terms of employment, value of output and capital invested
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Calcium
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term lime connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, quicklime specifically applies to the single chemical compound calcium oxide. Calcium
Calcium oxide that survives processing without reacting in building products such as cement is called free lime.[5] Quicklime is relatively inexpensive
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A brick is building material used to make walls, pavements and other elements in masonry construction. Traditionally, the term brick referred to a unit composed of clay, but it is now used to denote any rectangular units laid in mortar. A brick can be composed of clay-bearing soil, sand, and lime, or concrete materials. Bricks are produced in numerous classes, types, materials, and sizes which vary with region and time period, and are produced in bulk quantities. Two basic categories of bricks are fired and non-fired bricks. Block is a similar term referring to a rectangular building unit composed of similar materials, but is usually larger than a brick. Lightweight bricks (also called lightweight blocks) are made from expanded clay aggregate. Fired bricks are one of the longest-lasting and strongest building materials, sometimes referred to as artificial stone, and have been used since circa 4000 BC
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Europe
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Europe is a continent located entirely in the Northern Hemisphere
Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic
Arctic Ocean to the north, the Atlantic Ocean
Atlantic Ocean to the west, and the Mediterranean Sea to the south. It comprises the westernmost part of Eurasia. Since around 1850, Europe
Europe is most commonly considered as separated from Asia
Asia by the watershed divides of the Ural and Caucasus
Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits.[5] Though the term "continent" implies physical geography, the land border is somewhat arbitrary and has moved since its first conception in classical antiquity
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