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Eolianite
Eolianite or aeolianite is any rock formed by the lithification of sediment deposited by aeolian processes; that is, the wind. In common use, however, the term refers specifically to the most common form of eolianite: coastal limestone consisting of carbonate sediment of shallow marine biogenic origin, formed into coastal dunes by the wind, and subsequently lithified. It is also known as kurkar in the Middle East, miliolite in India and Arabia, and grès dunaire in the eastern Mediterranean. eolianite has a hardness of 4.3 and is very dull. Streak is light brown. Description Sayles coined the term in 1931, when he described the dune-shaped hills of Bermuda, consisting of bioclastic grainstones. Thus, Bermuda is considered the type locality for carbonate eolianite facies, with clearly defined cross-bedding, foresets, and topsets. Deposition is controlled by glacio-eustatic changes, with eolianites forming during interglaciations. Eolianites occur along the margins of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolianite
Eolianite or aeolianite is any rock formed by the lithification of sediment deposited by aeolian processes; that is, the wind. In common use, however, the term refers specifically to the most common form of eolianite: coastal limestone consisting of carbonate sediment of shallow marine biogenic origin, formed into coastal dunes by the wind, and subsequently lithified. It is also known as kurkar in the Middle East, miliolite in India and Arabia, and grès dunaire in the eastern Mediterranean. eolianite has a hardness of 4.3 and is very dull. Streak is light brown. Description Sayles coined the term in 1931, when he described the dune-shaped hills of Bermuda, consisting of bioclastic grainstones. Thus, Bermuda is considered the type locality for carbonate eolianite facies, with clearly defined cross-bedding, foresets, and topsets. Deposition is controlled by glacio-eustatic changes, with eolianites forming during interglaciations. Eolianites occur along the margins of the gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bermuda
) , anthem = "God Save the King" , song_type = National song , song = "Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , established_title2 = English settlement , established_date2 = 1609 (officially becoming part of the Colony of Virginia in 1612) , official_languages = English , demonym = Bermudian , capital = Hamilton , coordinates = , largest_city = Hamilton , ethnic_groups = , ethnic_groups_year = 2016 , government_type = Parliamentary dependency under a constitutional monarchy , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_name2 = Rena Lalgie , leader_title3 = Premier , leader_name3 = Edward David Burt , legislature = Parliament , upper_house = Senate , lower_house = House of Assembly , area_km2 = 53.2 , area_sq_mi = 20.54 , area_rank = , percent_water = 27 , elevation_max_m = 7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone ( sedimentary rocks) through lithification. Sediments are most often transported by water ( fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Classification Sediment can be classified based on its grain size, grain s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rottnest Island
Rottnest Island ( nys, Wadjemup), often colloquially referred to as "Rotto", is a island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-class reserve, the highest level of protection afforded to public land. Together with Garden Island, Rottnest Island is a remnant of Pleistocene dune ridges. Along with several other islands, Rottnest became separated from the mainland around 7,000 years ago, when sea levels rose; the traditional Noongar name for the island is ''Wadjemup'', which means "place across the water where the spirits are". Human artefacts have been found on the island dating back at least 30,000 years, but visitation and habitation of the island by the Noongar people appears to have ceased following its separation from the mainland. The island was first documented by Willem de Vlamingh in 1696, who called it t Eylandt 't Rottenest'' ("Rats' Nest Island") after the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kurkar
Kurkar ( ar, كركار / he, כורכר) is the term used in Palestinian Arabic and modern Hebrew for the rock type of which lithified sea sand dunes consist. The equivalent term used in Lebanon is ramleh.[Aharon Horowitz. ''The Quaternary of Israel.'' Page 109. Academic Press, New York, 1979. . https://books.google.com/books?id=uT-0BQAAQBAJ&pg=PA109&lpg=PA109&dq=arabic+kurkar&source=bl&ots=jsSFmx-BO4&sig=a7zcZmxiJAoUMrqxs2u7f9u6fPQ&hl=en&sa=X&ved=0ahUKEwjCx7ynisrKAhWFkg8KHQwHCssQ6AEIODAG#v=onepage&q=arabic%20kurkar&f=false] History Kurkar is the regional name for an aeolian quartz sandstone with carbonate cement, in other words an eolianite or a calcarenite (calcareous sandstone or grainstone), found on the Levantine coast of the Mediterranean Sea in Turkey, Palestine, Syria, Lebanon, Israel, Francisc Dov Por. ''The Legacy of Tethys: An Aquatic Biogeography of the Levant.'' Pages 46-48, 54. Springer, New York, 1989, Monographiae Biologicae (Book 63), . "... around Tel Aviv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grainstone
Under the Dunham classification (Dunham, 1962) system of limestones, a grainstone is defined as a grain-supported carbonate rock that contains less than 1% mud-grade material. This definition has recently been clarified as ''a carbonate-dominated rock that does not contain any carbonate mud and where less than 10% of the components are larger than 2 mm.'' The spaces between grains may be empty (pores) or filled by cement. The identification of grainstone The presence of any primary carbonate mud precludes a classification of grainstone. A study of the use of carbonate classification systems by Lokier and Al Junaibi (2016) highlighted that the most common source of confusion in the classification of grainstone was to misidentify fine-grained internal micrite, generated by in-situ processes, as clay–silt grade sediment - thus resulting in the misidentification of grainstone as packstone Under the Dunham classification (Dunham, 1962Dunham, R.J. (1962) Classification of carbonate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dune
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat regions covered with wind-swept sand or dunes with little or no vegetation are called '' ergs'' or ''sand seas''. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter ''slip face'' in the lee side. The valley or trough between dunes is called a ''dune slack''. Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in other areas where poorly cemented s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seashell
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have decomposed or been eaten by another animal. A seashell is usually the exoskeleton of an invertebrate (an animal without a backbone), and is typically composed of calcium carbonate or chitin. Most shells that are found on beaches are the shells of marine mollusks, partly because these shells are usually made of calcium carbonate, and endure better than shells made of chitin. Apart from mollusk shells, other shells that can be found on beaches are those of barnacles, horseshoe crabs and brachiopods. Marine annelid worms in the family Serpulidae create shells which are tubes made of calcium carbonate cemented onto other surfaces. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interglaciation
An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene interglacial began at the end of the Pleistocene, about 11,700 years ago. Pleistocene During the 2.5 million years of the Pleistocene, numerous glacials, or significant advances of continental ice sheets, in North America and Europe, occurred at intervals of approximately 40,000 to 100,000 years. The long glacial periods were separated by more temperate and shorter interglacials. During interglacials, such as the present one, the climate warms and the tundra recedes polewards following the ice sheets. Forests return to areas that once supported tundra vegetation. Interglacials are identified on land or in shallow epicontinental seas by their paleontology. Floral and faunal remains of species pointing to temperate climate and indicating a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
