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Santo Domingo Formation
Santo Domingo Formation ( es, Formación Santo Domingo) is a mainly marine Miocene sedimentary formation located in south–central Chile.Encinas et al., 2008 The formation was defined by R. Martínez Pardo and Mario Pino in 1979 and named after the roadcut locality they studied about southeast of Valdivia. Sediments of the formation accumulated in Valdivia and Osorno–Llanquihue Basin.Elgueta ''et al.''., 2000, p.10 The formations overlie a basement consisting of metamorphic and igneous rocks, the Bahía Mansa Metamorphic Complex and Cretaceous granitoids, respectively. In parts, it further overlies the coal–bearing Pupunahue–Catamutún Formation. The sedimentary facies of the Santo Domingo Formation are composed of sandstone, siltstone, and mudstone with smaller amounts of conglomerate.Elgueta ''et al.''., 2000, p.16 The formation underlies Pliocene and Quaternary sediments. Fossil content Some of the trace fossils that can be found in the Santo Domingo Formation ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laguna Brava Formation
Laguna Brava Formation ( es, Formación Laguna Brava), formerly referred to as Santo Domingo Formation, is a Late Eocene (Tinguirirican in the SALMA classification) sedimentary formation located in the Argentine Northwest.Quebrada de Santa Domingo at .org The formation contains beds with described as '' Gruipeda domingue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdivia Basin
Valdivia (; Mapuche: Ainil) is a city and commune in southern Chile, administered by the Municipality of Valdivia. The city is named after its founder Pedro de Valdivia and is located at the confluence of the Calle-Calle, Valdivia, and Cau-Cau Rivers, approximately east of the coastal towns of Corral and Niebla. Since October 2007, Valdivia has been the capital of Los Ríos Region and is also the capital of Valdivia Province. The national census of 2017 recorded the commune of Valdivia as having 166,080 inhabitants (''Valdivianos''), of whom 150,048 were living in the city. The main economic activities of Valdivia include tourism, wood pulp manufacturing, forestry, metallurgy, and beer production. The city is also the home of the Austral University of Chile, founded in 1954 and the Centro de Estudios Científicos. The city of Valdivia and the Chiloé Archipelago were once the two southernmost outliers of the Spanish Empire. From 1645 to 1740 the city depended d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoophycos
''Zoophycos'' is a somewhat cosmopolitan ichnogenus thought to be produced by moving and feeding polychaete worms. Appearance ''Zoophycos'' occurs in two forms, one planar, and one which resembles a corkscrew. In the latter helicoidal form, successive turns have larger or smaller radii. A marginal tube surrounds the perimeter of the corkscrew, linked to the vertical shaft that connects the burrow to the surface. Spreiten occur between the marginal tube and the corkscrew axis. The burrows can exceed a metre in vertical and horizontal dimension. Ethology One hypothesis proposes that ''Zoophycos'' represents gardening behaviour, in a similar fashion to '' Palaeodictyon''. According to this view, there should be a fractionation of carbon isotopes between the burrow infills and the matrix – but such differentiation was not observed in Quaternary instances from deep-water cores off the Portuguese coast.(Variation in morphology between different zoophycos 'species' means tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or mineralization. The study of such trace fossils is ichnology and is the work of ichnologists. Trace fossils may consist of impressions made on or in the substrate by an organism. For example, burrows, borings (bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints and feeding marks and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ordini). The term "quaternary" was introduced by Jules Desnoye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formation), and the changes that may occur in those attributes over a geographic area. A facies encompasses all of the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock. The term facies was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy, which replaced the earlier notions of Neptunism. Types of facies Sedimentary facies Ideally, a Sedimentary structures, sedimentary facies is a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or environment. Sedimentary facies are either descriptive or interpretative. Sedimentary facies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and distorti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdivia
Valdivia (; Mapuche: Ainil) is a city and commune in southern Chile, administered by the Municipality of Valdivia. The city is named after its founder Pedro de Valdivia and is located at the confluence of the Calle-Calle, Valdivia, and Cau-Cau Rivers, approximately east of the coastal towns of Corral and Niebla. Since October 2007, Valdivia has been the capital of Los Ríos Region and is also the capital of Valdivia Province. The national census of 2017 recorded the commune of Valdivia as having 166,080 inhabitants (''Valdivianos''), of whom 150,048 were living in the city. The main economic activities of Valdivia include tourism, wood pulp manufacturing, forestry, metallurgy, and beer production. The city is also the home of the Austral University of Chile, founded in 1954 and the Centro de Estudios Científicos. The city of Valdivia and the Chiloé Archipelago were once the two southernmost outliers of the Spanish Empire. From 1645 to 1740 the city depended directly on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cut (earthmoving)
In civil engineering, a cut or cutting is where soil or rock from a relative rise along a route is removed. The term is also used in river management to speed a waterway's flow by short-cutting a meander. Cuts are typically used in road, rail, and canal construction to reduce the length and grade of a route. Cut and fill construction uses the spoils from cuts to fill in defiles to cost-effectively create relatively straight routes at steady grades. Cuts are used as alternatives to indirect routes, embankments, or viaducts. They also have the advantage of comparatively lower noise pollution than elevated or at-grade solutions. History The term ''cutting'' appears in the 19th century literature to designate rock cuts developed to moderate grades of railway lines. ''Railway Age's Comprehensive Railroad Dictionary'' defines a cut as "a passage cut for the roadway through an obstacle of rock or dirt." Creation Cuts can be created by multiple passes of a shovel, grader, scrap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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