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Tafoni
Tafoni (singular: tafone) are cavities that develop in granular rock. Although there are various definitions in the scientific literature, tafoni are commonly defined as small (less than ) to large (greater than ) cavity features that develop in either natural or manmade, vertical to steeply sloping, exposures of granular rock (i.e., granite, sandstone) with smooth concave walls, and often round rims and openings. Recognized subcategories of tafoni include ''honeycomb'', ''stonelace'', ''alveolar'' (less than ), ''sidewall'', ''basal'', ''nested'', and ''relic tafoni''. It is also commonly synonymous with ''nido d’ape roccioso'' in Italian.Paradise, T.R., 2013. ''Tafoni and other rock basins.'' In: Shroder, J. (Editor in Chief), Pope, G.A., (Ed.), ''Treatise on Geomorphology.'' Academic Press, San Diego, CA, vol. 4, Weathering and Soils Geomorphology, pp.111–126. The etymology of the word ''tafoni'' is unclear. Tafoni may come from the Greek word ''taphos'', ''tomb'', or it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honeycomb Weathering
Honeycomb weathering, also known as honeycombs, honeycombed sandstone, is a form of cavernous weathering that consists of regular, tightly adjoining, and commonly patterned cavities that are developed in weathered bedrock; are less than in size; and resemble a honeycombed structure. Honeycombs also been called alveoli, lacework, stonelace, fretting, or miniature tafoni weathering.Bruthans, J., Filippi, M., Slavík, M. and Svobodová, E., 2018. ''Origin of honeycombs: Testing the hydraulic and case hardening hypotheses.'' ''Geomorphology'', 303, pp.68-83.Paradise, T.R., 2013. ''Tafoni and other rock basins.'' In: Shroder, J. (Editor in Chief), Pope, G.A., (Ed.), ''Treatise on Geomorphology.'' Academic Press, San Diego, CA, vol. 4, Weathering and Soils Geomorphology, pp.111–126. The size at which honeycombs are differentiated from tafoni varies greatly in the scientific literature and lacks an official consensus.Groom, K.M., Allen, C.D., Mol, L., Paradise, T.R. and Hall, K., 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haloclasty
Haloclasty (also called salt weathering) is a type of physical weathering caused by the growth and thermal expansion of salt crystals. The process starts when saline water seeps into deep cracks and evaporates depositing salt crystals. When the rocks are then heated, the crystals will expand putting pressure on the surrounding rock which will over time splinter the stone into fragments. Salt crystallization may also take place when solutions decompose rocks (for example, limestone, chalk, or sandstone ) to form salt solutions of sodium sulfate, sodium carbonate, or calcium carbonate, from which water evaporates to form their respective salt crystals. The salts which have proved most effective in disintegrating rocks are sodium sulfate, magnesium sulfate, and calcium chloride Calcium chloride is an inorganic compound, a Salt (chemistry), salt with the chemical formula . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Hardening Of Rocks
Case hardening is a weathering phenomenon of rock surface induration. It is observed commonly in: felsic alkaline rocks, such as nepheline syenite, phonolite and trachyte; pyroclastic rocks, as pyroclastic flow deposit, fine air-fall deposits and vent-filling pyroclastic deposits; sedimentary rocks, as sandstone and mudstone. Weathering process Chemical weathering alters the minerals constituent of rock surface. Decomposition of mafic and opaque minerals releases ions and colloids of iron, magnesium, calcium and sulphur. Alteration of feldspars and feldspathoids releases silica colloid. These materials are reached and transported by surface water. The remnant materials are highly aluminous and siliceous. They could have certain mechanical firmness of own minerals, however no cohesion. Therefore, physical disintegration of the rock takes place to form the surface. In certain cases, the weathered surface obtains mechanical firmness higher than subsurface. The reached material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negev
The Negev ( ; ) or Naqab (), is a desert and semidesert region of southern Israel. The region's largest city and administrative capital is Beersheba (pop. ), in the north. At its southern end is the Gulf of Aqaba and the resort town, resort city and port of Eilat. It contains several development towns, including Dimona, Arad, Israel, Arad, and Mitzpe Ramon, as well as a number of small Negev Bedouin, Bedouin towns, including Rahat, Tel Sheva, and Lakiya. There are also several kibbutzim, including Revivim and Sde Boker; the latter became the home of Israel's first Prime Minister of Israel, prime minister, David Ben-Gurion, after his retirement from politics. Although historically part of a separate region (known during the Roman Empire, Roman period as Arabia Petraea), the Negev was added to the proposed area of Mandatory Palestine, of which large parts later became Israel, on 10 July 1922, having been conceded by British representative St John Philby "in Emirate of Transjordan, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in life on Earth; prior to the Period, the majority of living organisms were small, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it was not until the Cambrian that fossil diversity seems to rapidly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isle Of Skye
The Isle of Skye, or simply Skye, is the largest and northernmost of the major islands in the Inner Hebrides of Scotland. The island's peninsulas radiate from a mountainous hub dominated by the Cuillin, the rocky slopes of which provide some of the most dramatic mountain scenery in the country.#Slesser70, Slesser (1981) p. 19. Although has been suggested to describe a winged shape, no definitive agreement exists as to the name's origin."Gaelic Culture" . VisitScotland. Retrieved 5 January 2013. The island has been occupied since the Mesolithic period, and over its history has been occupied at various times by Celtic tribes including the Picts and the Gaels, Scandinavian Vikings, and most notably the powerful integrated Norse-Gaels clans of Clan MacLeod, MacLeod and Clan Donald, MacDonald. The island was considered to be under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total population of over 84 million in an area of , making it the most populous member state of the European Union. It borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The Capital of Germany, nation's capital and List of cities in Germany by population, most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr. Settlement in the territory of modern Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts. Various Germanic peoples, Germanic tribes have inhabited the northern parts of modern Germany since classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheinland-Pfalz
Rhineland-Palatinate ( , ; ; ; ) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the sixteen states. Mainz is the capital and largest city. Other cities are Ludwigshafen am Rhein, Koblenz, Trier, Kaiserslautern, Worms, and Neuwied. It is bordered by North Rhine-Westphalia, Saarland, Baden-Württemberg and Hesse and by France, Luxembourg and Belgium. Rhineland-Palatinate was established in 1946 after World War II, from parts of the former states of Prussia (part of its Rhineland and Nassau provinces), Hesse ( Rhenish Hesse) and Bavaria (its former outlying Palatinate kreis or district), by the French military administration in Allied-occupied Germany. Rhineland-Palatinate became part of the Federal Republic of Germany in 1949 and shared the country's only border with the Saar Protectorate until the latter was returned to German control in 1957. Rhineland-Palatinate's natural and cultural her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of 2024, San Francisco is the List of California cities by population, fourth-most populous city in the U.S. state of California and the List of United States cities by population, 17th-most populous in the United States. San Francisco has a land area of at the upper end of the San Francisco Peninsula and is the County statistics of the United States, fifth-most densely populated U.S. county. Among U.S. cities proper with over 250,000 residents, San Francisco is ranked first by per capita income and sixth by aggregate income as of 2023. San Francisco anchors the Metropolitan statistical area#United States, 13th-most populous metropolitan statistical area in the U.S., with almost 4.6 million residents in 2023. The larger San Francisco Bay Area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual Climate of Antarctica#Precipitation, precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the Lowest temperature recorded on Earth, lowest measured temperature on Earth, . The coastal regions can reach temperatures over in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic
The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway (Nordland, Troms, Finnmark, Svalbard and Jan Mayen), northernmost Sweden (Västerbotten, Norrbotten and Lapland (Sweden), Lappland), northern Finland (North Ostrobothnia, Kainuu and Lapland (Finland), Lappi), Russia (Murmansk Oblast, Murmansk, Siberia, Nenets Autonomous Okrug, Nenets Okrug, Novaya Zemlya), the United States (Alaska), Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), and northern Iceland (Grímsey and Kolbeinsey), along with the Arctic Ocean and adjacent seas. Land within the Arctic region has seasonally varying cryosphere, snow and ice cover, with predominantly treeless permafrost under the tundra. Arctic seas contain seasonal sea ice in many places. The Arctic region is a unique area among Earth's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
