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Parga Formation
Parga Formation ( es, Formación Parga) is a geological formation of sedimentary rock in south-central Chile. The sediments of the formation were deposited during the Late Oligocene and Middle Miocene epochs. The formation's lower sections are made up of conglomerate, sandstone and mudstone some of which is rich in organic material. Additionally there are thin beds of tuff and coal. The formation's composition indicates that sedimentation occurred in an estuarine (paralic) and marine environments. Stratigraphically it overlies the Bahía Mansa Metamorphic Complex and is similar in age and type to Lacui Formation to the south and Cheuquemó and Santo Domingo Formation to the north. It is overlain across an angular unconformity by Pliocene or Quaternary sediments. The formation is intruded by porphyritic trachyte of Oligocene to Miocene age (Ancud Volcanic Complex). The outcrops of the formation are restricted to a NW-SE strip near Caleta Parga north of the estuary of Maullín Rive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith (geologist), William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of Stratum, strata or rock layering and the importance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Series Of South America
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Chile
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Mining In Chile
In Chile, coal mining is restricted to a few places located in its southern half. Energy originating from coal stands for 11,6% of Chile's electricity consumption.Carbon . CNE. Accessed on September 10. 2012. Currently the country is not considered a major producer of coal. The three zones of mining are Zona Central Sur (36–38° S), Zona Sur (39–42° S) and Zona Austral (51–54° S) in southernmost Chile. Most of the coal resources of Chile lie in Zona Austral at southernmost Chile. Zona Central Sur  ...
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National Geology And Mining Service
250px, Sernageomin building in Providencia, Santiago. The National Geology and Mining Service ( es, Servicio Nacional de Geología y Minería; SERNAGEOMIN) is a Chilean government agency. Its function is to provide geological information and advice, technical assistance to government, public and private interests, and to regulate the mining industry in Chile. The service was formed in 1980 by the combination of the previous Institute of Geological Investigations and the State Mines Service. Its director is appointed by the President of Chile The president of Chile ( es, Presidente de Chile), officially known as the President of the Republic of Chile ( es, Presidente de la República de Chile), is the head of state and head of government of the Republic of Chile. The president is r ....United States Geological Survey">United States Geological Survey web site, The volcanos in Chile are monitored by SERNAGEOMIN Since 1974, SERNAGEOMIN has published the scientific journal ''An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maullín River
Maullín River( es, Río Maullín) is a river of Chile located in the Los Lagos Region. The river originates as the outflow of Llanquihue Lake, and flows generally southwestward, over a number of small waterfalls, emptying into the Gulf of Coronados.Image Science and Analysis Laboratory, NASA-Johnson Space CenterNM23-720-597 "Maullin River, Puerto Montt," ''Chile,'' Winter/Spring 1997, (16 July 2007) The lower course of the river is a tidal estuary. History Franciscan Friar Francisco Alvarez Villanueva mention in 1780 Maullín River as the limit between the Spanish possessions and the " Cunco nation" to the north. The river was first explored extensively in 1856 and 1857 by the Chilean Navy officers Francisco Hudson Ancud.html" ;"title="Punta Arenas by sea from Ancud">Punta Arenas by sea from Ancud, and in orange Hudson's proposed route. The red dot shows the 20 km wide Ofqui Isthmus the only obstacle that makes this route intransitable. --> Francisco Hudson C ... and Francisco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancud Volcanic Complex
Ancud Volcanic Complex ( es, Complejo Volcánico de Ancud) is a volcanic complex of Oligocene and Miocene age located around Ancud with exposures in Chiloé Island, the Chilean mainland and smaller islets. Three subunits are recognized in the complex: Hueihuen, Teguaco and Cocotue. The complex is part of the mid-Tertiary coastal magmatic belt in south-central Chile. See also * Parga Formation * 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 ... References {{Geology of Chile Geologic formations of Chile Miocene South America Oligocene South America Oligocene volcanism Miocene volcanism Paleogene Chile Neogene Chile Volcanoes of Los Lagos Region Geology of Los Lagos Region Chiloé Archipelago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trachyte
Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and alkali metals. It is the volcanic equivalent of syenite. Trachyte is common wherever alkali magma is erupted, including in late stages of ocean island volcanismMacDonald 1983, pp. 51-52 and in continental rift valleys, above mantle plumes,Philpotts and Ague 2009, pp. 390-394 and in areas of back-arc extension. Trachyte has also been found in Gale crater on Mars. Trachyte has been used as decorative building stone and was extensively used as dimension stone in the Roman Empire and the Republic of Venice. Chemical composition Trachyte has a silica content of 60 to 65% and an alkali oxide content of over 7%. This gives it less SiO2 than rhyolite and more (Na2O plus K2O) than dacite. These chemical differences are consistent with the positio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porphyry (geology)
Porphyry ( ) is a textural term for an igneous rock consisting of coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass. The larger crystals are called phenocrysts. In its non-geologic, traditional use, the term ''porphyry'' refers to the purple-red form of this stone, valued for its appearance. The term ''porphyry'' is from the Ancient Greek (), meaning "purple". Purple was the color of royalty, and the "imperial porphyry" was a deep purple igneous rock with large crystals of plagioclase. Some authors claimed the rock was the hardest known in antiquity. Thus, "imperial"-grade porphyry was prized for monuments and building projects in Imperial Rome and thereafter. Subsequently, the name was given to any igneous rocks with large crystals. The adjective ''porphyritic'' now refers to a certain texture of igneous rock regardless of its chemical and mineralogical composition. Its chief characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrusion (geology)
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March 27, 2017.Igneous intrusive rocks, accessdate: March 27, 2017.Britannica.comintrusive rock , geology , Britannica.com accessdate: March 27, 2017. Intrusion is one of the two ways igneous rock can form. The other is extrusion, such as a volcanic eruption or similar event. An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet. In contrast, an ''extrusion'' consists of extrusive rock, formed above the surface of the crust. Some geologists use the term plutonic rock synonymously with intrusive rock, but other geologists subdivide intrusive rock, by crystal size, into coarse-grained plutonic rock (typically formed deeper in the Earth's crust in batholiths or stocks) an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Unconformity
An unconformity is a buried erosion surface, erosional or non-depositional surface separating two Rock (geology), rock masses or Stratum, strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the Sedimentary rocks, sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity Law of superposition, are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents Geologic time, time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
