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Ripple Mark
In geology, ripple marks are sedimentary structures (i.e., bedforms of the lower flow regime) and indicate agitation by water (Ocean current, current or wind wave, waves) or directly by wind. Defining ripple cross-laminae and asymmetric ripples * ''Current ripple marks'', ''unidirectional ripples'', or ''asymmetrical ripple marks'' are asymmetrical in profile, with a gentle up-current slope and a steeper down-current slope. The down-current slope is the angle of repose, which depends on the shape of the sediment. These commonly form in fluvial and Aeolian processes, aeolian depositional environments, and are a signifier of the lower part of the Lower Flow Regime. * Ripple cross-laminae forms when deposition takes place during migration of current or wave ripples. A series of cross-laminae are produced by superimposing migrating ripples. The ripples form lateral to one another, such that the crests of vertically succeeding laminae are out of phase and appear to be advancing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ripple Marks In Moenkopi Formation Rock Off Of Capitol Reef Scenic Drive
Ripple may refer to: Science and technology * Capillary wave, commonly known as ripple, a wave traveling along the phase boundary of a fluid ** Ripple, more generally a disturbance, for example of spacetime in gravitational waves * Ripple (electrical), residual periodic variation in DC voltage during ac to dc conversion ** Ripple current, pulsed current draw caused by some non-linear devices and circuits ** Frequency-domain ripple ** Ringing (signal), oscillation of a signal, particularly in the step response * Polarization ripples, appearing after irradiation of a solid by energy flux (laser, ions, etc.) * Ripple marks, as identified in sediments and sedimentary rocks * Ripple (payment protocol), a real-time payment system by Ripple Labs * Ripple control, a form of electrical load management * Various brainwave patterns, including those which follow Sharp waves and ripples, sharp waves in the hippocampus * Ripple I and Ripple II, 1962 US nuclear bomb tests in Operation Dominic Org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur Ridge
Dinosaur Ridge is a segment of the Dakota Hogback in the Morrison Fossil Area National Natural Landmark located in Jefferson County, Colorado, near the town of Morrison, Colorado, Morrison and just west of Denver. In 1877 Arthur Lakes, a clergyman, teacher, and amateur paleontologist from Golden, CO, and Henry Beckwith, a retired naval officer, discovered the first ever dinosaur material in the Morrison Formation at Dinosaur Ridge. The same year, excavation began under the direction of Yale paleontologist Dr. Othniel Charles Marsh. The first identified Stegosaurus fossils in the world were discovered here, and fossil bones found in the layers of rock here represent some well-known dinosaurs, including ''Apatosaurus'', ''Camarasaurus,'' ''Diplodocus'', and ''Allosaurus''. In 1973, the area was recognized as an outstanding example of the nation's natural heritage, and was designated a National Natural Landmark by the National Park Service. The area was expanded in June 2011, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dakota Formation
The Dakota is a sedimentary rock, sedimentary geologic unit name of Formation (stratigraphy), formation and Group (stratigraphy), group rank in Midwestern North America. The Dakota units are generally composed of sandstones, mudstones, clays, and shales deposited in the Mid-Cretaceous opening of the Western Interior Seaway.Monroe, James S. and Wicander, Reed (1997) ''The Changing Earth: Exploring Geology and Evolution'' (2nd edition) Wadsworth Publishing Company, Belmont, California, page 610, The usage of the name Dakota for this particular Albian-Cenomanian strata is exceptionally widespread; from British Columbia and Alberta to Montana and Wisconsin to Colorado and Kansas to Utah and Arizona. It is famous for producing massive colorful rock formations in the Rocky Mountains and the Great Plains of the United States, and for preserving both Fossil track, dinosaur footprints and early deciduous tree leaves. Owing to extensive weathering of older rocks during the Jurassic and Tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crest Trough
Crest or CREST may refer to: Buildings * The Crest (Huntington, New York), a historic house in Suffolk County, New York * "The Crest", an alternate name for 63 Wall Street, in Manhattan, New York * Crest Castle (Château Du Crest), Jussy, Switzerland * Crest House, a building, now in ruins, at the summit of Mount Evans in Colorado * Crest Theatre, a historic theatre in downtown Sacramento, California * Nimoy Theater, formerly Majestic Crest Theatre, Los Angeles, California * Crest Theatre, in Old School Square, Delray Beach, Florida Business or commerce * Crest (toothpaste), a brand of toothpaste * Crest Audio, an American manufacturer of power amplifiers and mixing consoles * Crest Animation Productions, an animation studio in Burbank, California * Crest Animation Studios, an animation studio in India * Crest Books, an imprint of now defunct Fawcett Publications * Crest Hotels, a defunct hotel chain in the UK * Crest Manufacturing Company, producer of the Crest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Aeolian Ridges
Transverse aeolian ridges (TARs) are visually bright features commonly found in Topography, topographic depressions on Mars. These small-scale and relict Bedform, bedforms were first seen in narrow-angle images from the Mars Global Surveyor, Mars Orbiter Camera (MOC) and were called “ridges” to preserve both Dune, dunes and Ripple marks#Ripple marks in different environments, ripples as formative mechanisms. While TARs are widespread on Mars, their formation, age, composition, and role in past Martian Sediment transport, sediment cycles remain poorly constrained. Aeolian bedforms Aeolian processes, Aeolian bedforms are typically classified into either Ripple marks#Ripple marks in different environments, ripples or Dune, dunes based on their morphologies and formative mechanisms. Dunes are larger (>0.5 m or taller on Earth), typically asymmetrical in cross-profile, and are the product of hydrodynamic instability related to sand flux, the local topography, shear stress exerted by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltation (geology)
In geology, saltation () is a specific type of particle transport by fluids such as wind or water. It occurs when loose materials are removed from a bed and carried by the fluid, before being transported back to the surface. Examples include pebble transport by rivers, sand drift over desert surfaces, soil blowing over fields, and snow drift over smooth surfaces such as those in the Arctic or Canadian Prairies. Process At low fluid velocities, loose material rolls downstream, staying in contact with the surface. This is called ''creep'' or ''reptation''. Here the forces exerted by the fluid on the particle are only enough to roll the particle around the point of contact with the surface. Once the wind speed reaches a certain critical value, termed the ''impact'' or ''fluid threshold'', the drag and lift forces exerted by the fluid are sufficient to lift some particles from the surface. These particles are accelerated by the fluid, and pulled downward by gravity, causing them t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1969 Afghanistan (Sistan) Wind Ripples
1969 (Roman numerals, MCMLXIX) was a common year starting on Wednesday of the Gregorian calendar, the 1969th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 969th year of the 2nd millennium, the 69th year of the 20th century, and the 10th and last year of the 1960s decade. Events January * January 4 – The Government of Spain hands over Ifni to Morocco. * January 5 – Ariana Afghan Airlines Flight 701 crashes into a house on its approach to London's Gatwick Airport, killing 50 of the 62 people on board and two of the home's occupants. * January 14 – USS Enterprise fire, An explosion aboard the aircraft carrier USS Enterprise (CVN-65), USS ''Enterprise'' near Hawaii kills 28 and injures 314. * January 16 – First successful docking of two crewed spacecraft in orbit and the first transfer of crew from one space vehicle to another (by a space walk) between Soviet craft Soyuz 5 and Soyuz 4. * January 18 – Failure of Soyuz 5's service module to separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Bed
A streambed or stream bed is the bottom of a stream or river and is confined within a Stream channel, channel or the Bank (geography), banks of the waterway. Usually, the bed does not contain terrestrial (land) vegetation and instead supports different types of aquatic vegetation (aquatic plant), depending on the type of streambed material and water velocity. Streambeds are what would be left once a stream is no longer in existence. The beds are usually well preserved even if they get buried because the banks and canyons made by the stream are typically hard, although soft sand and debris often fill the bed. Dry, buried streambeds can actually be underground water pockets. During times of rain, sandy streambeds can soak up and retain water, even during dry seasons, keeping the water table close enough to the surface to be obtainable by local people. The nature of any streambed is always a function of the flow dynamics and the local geologic materials. The climate of an area wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinusoidal
A sine wave, sinusoidal wave, or sinusoid (symbol: ∿) is a periodic wave whose waveform (shape) is the trigonometric sine function. In mechanics, as a linear motion over time, this is '' simple harmonic motion''; as rotation, it corresponds to '' uniform circular motion''. Sine waves occur often in physics, including wind waves, sound waves, and light waves, such as monochromatic radiation. In engineering, signal processing, and mathematics, Fourier analysis decomposes general functions into a sum of sine waves of various frequencies, relative phases, and magnitudes. When any two sine waves of the same frequency (but arbitrary phase) are linearly combined, the result is another sine wave of the same frequency; this property is unique among periodic waves. Conversely, if some phase is chosen as a zero reference, a sine wave of arbitrary phase can be written as the linear combination of two sine waves with phases of zero and a quarter cycle, the ''sine'' and ''cosine'' co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetric
Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is invariant under some transformations, such as translation, reflection, rotation, or scaling. Although these two meanings of the word can sometimes be told apart, they are intricately related, and hence are discussed together in this article. Mathematical symmetry may be observed with respect to the passage of time; as a spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including theoretic models, language, and music. This article describes symmetry from three perspectives: in mathematics, including geometry, the most familiar type of symmetry for many people; in science and nature; and in the arts, covering architecture, art, and music. The opposite of symmetry is asymmetr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
