|
Flute Cast
Sole marks are sedimentary structures found on the bases of certain strata, that indicate small-scale (usually on the order of centimetres) grooves or irregularities. This usually occurs at the interface of two differing lithologies and/or grain sizes. They are commonly preserved as casts of these indents on the bottom of the overlying bed (like flute casts). This is similar to casts and molds in fossil preservation. Occurring as they do only at the bottom of beds, and their distinctive shapes, they can make useful way up structures and paleocurrent indicators. Sole markings are found most commonly in turbidite deposits, but are also often seen in modern river beds and tidal channels. History Sole markings were first recognized in the Devonian rocks of New York State by James Hall in 1843. Originally, the features found on the undersides of beds were called ''hieroglyphs'', ''fucoids'', and ''bio hieroglyphs'', because of their structure and how they were thought to be cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groove Casts
Groove or Grooves may refer to: Music * Groove (music) * Groove (drumming) * The Groove (band), an Australian rock/pop band of the 1960s * The Groove (Sirius XM), a US radio station * Groove 101.7FM, a former Perth, Australia, radio station * ''Groove'' (Eurogliders album), 1988 * ''Groove'' (Billy Crawford album), 2009 * ''Groove'' (Richard "Groove" Holmes album), 1961 * "The Groove" (song), a 1980 song by Rodney Franklin * Groove Music, Microsoft software * Groove Records, record label * "Groove", a song by Exo from '' Obsession'' * "Groove", song by Jay Haze from '' A Bugged Out Mix'' * "The Groove", 2003 song by Muse, B-side to " Time Is Running Out" * The Groove, a dance club in the Universal CityWalk section of Universal Orlando Resort Other uses * Grooves (archaeology), long and narrow indentations * Groove (engineering), a long and narrow indentation built into a material * ''Groove'' (film), a 2000 US film * Groove (joinery), a slot cut parallel to the grain * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flute Casts Mcr1
The flute is a family of classical music instrument in the woodwind group. Like all woodwinds, flutes are aerophones, meaning they make sound by vibrating a column of air. However, unlike woodwind instruments with reeds, a flute is a reedless wind instrument that produces its sound from the flow of air across an opening. According to the instrument classification of Hornbostel–Sachs, flutes are categorized as edge-blown aerophones. A musician who plays the flute is called a flautist or flutist. Flutes are the earliest known identifiable musical instruments, as paleolithic The Paleolithic or Palaeolithic (), also called the Old Stone Age (from Greek: παλαιός ''palaios'', "old" and λίθος ''lithos'', "stone"), is a period in human prehistory that is distinguished by the original development of stone too ... examples with hand-bored holes have been found. A number of flutes dating to about 53,000 to 45,000 years ago have been found in the Swabian Jura region of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Structures
Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different particle sizes are deposited on top of each other. These beds range from millimeters to centimeters thick and can even go to meters or multiple meters thick. Sedimentary structures such as cross-bedding, graded bedding, and ripple marks are utilized in stratigraphic studies to indicate original position of strata in geologically complex terrains and understand the depositional environment of the sediment. Flow structures There are two kinds of flow structures: bidirectional (multiple directions, back-and-forth) and unidirectional. Flow regimes in single-direction (typically fluvial) flow, which at varying speeds and velocities produce different structures, are called bedforms. In the ''lower flow regime'', the natural progression is from a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithology
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone. Lithology is the basis of subdividing rock sequences into individual lithostratigraphic units for the purposes of mapping and correlation between areas. In certain applications, such as site investigations, lithology is described using a standard terminology such as in the European geotechnical standard Eurocode 7. Rock type The naming of a lithology is based on the rock type. The three major rock types are igneous, sedimentary, and metamorphic. Igneous rocks are formed directly from magma, which is a mixture of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) 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, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. 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. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. 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. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Way Up Structure
A way up structure'', ''way up criterion, or geopetal indicator is a characteristic relationship observed in a sedimentary or volcanic rock, or sequence of rocks, that makes it possible to determine whether they are the right way up (i.e. in the attitude in which they were originally deposited, also known as "stratigraphic up" or "younging upwards") or have been overturned by subsequent deformation. This technique is particularly important in areas affected by thrusting and where there is a lack of other indications of the relative ages of beds within the sequence, such as in the Precambrian where fossils are rare. The original definition comes from Bruno Sander in 1936, translated from German to English in 1951, which states: ''Geopetal Fabrics'' - All the widely distributed spatial characters of a fabric that enable us to determine what was the relation of "top" to "bottom" at the time when the rock was formed are termed ''geopetal'' fabrics. Such fabrics are mechanical and che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocurrent
A paleocurrent or paleocurrent indicator is a geological feature (typically a sedimentary structure) that helps one determine the direction of flowing water in the geologic past. This is an invaluable tool in the reconstruction of ancient depositional environments. There are two main types of paleocurrent indicators: *''Unidirectional'', which give a clear, single direction of flow *''Bidirectional'', which give a good linear direction, but it is unclear which direction along the linear trend the water flowed. Paleocurrents are usually measured with an azimuth, or as a rake on a bedding plane, and displayed with a Rose Diagram to show the dominant direction(s) of flow. This is needed because in some depositional environments, like meandering rivers, the paleocurrent resulting from natural sinuosity has a natural variation of 180 degrees or more. Below are a partial list of common paleocurrent indicators: Unidirectional *Cross-bedding – the axis of a trough cross bed or the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbidite
A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing Turbidites were first properly described by Arnold H. Bouma (1962), who studied deepwater sediments and recognized particular "fining-up intervals" within deep water, fine-grained shales, which were anomalous because they started at pebble conglomerates and terminated in shales. This was anomalous because within the deep ocean it had historically been assumed that there was no mechanism by which tractional flow could carry and deposit coarse-grained sediments into the abyssal depths. Bouma cycles begin with an erosional contact of a coarse lower bed of pebble to granule conglomerate in a sandy matrix, and grade up through coarse then medium plane parallel sandstone; through cross-bedded sandstone; rippled cross-bedded sand/silty sand, and finally lami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Hall (paleontologist)
James Hall Jr. (September 12, 1811 – August 7, 1898) was an American geologist and paleontologist. He was a noted authority on stratigraphy and had an influential role in the development of paleontology in the United States. Early life James Hall was born in Hingham, Massachusetts, the oldest of four children. His parents, James Hall Sr. and Sousanna Dourdain Hall, had emigrated from England two years earlier. Hall developed an early interest in science and enrolled in Rensselaer Polytechnic Institute, a recently established college that emphasized student participation and focused on science. He was a student of Amos Eaton and Ebenezer Emmons, both notable geologists. Hall graduated with honors in 1832, received his master's degree in 1833, and remained at Rensselaer to teach chemistry and later geology. In 1836 a multi-year survey was established to collect information on the geology and natural history of New York. For purposes of the survey, the state was divided into f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
