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Des Plaines Crater
The Des Plaines crater or Des Plaines disturbance is recognized as an impact crater in Cook County, Illinois, United States. It is located beneath the eastern part of the city of Des Plaines, which is a suburb of Chicago. The Des Plaines crater is in diameter and covers an area of approximately . The age of the crater is unknown but is thought to be between 280 million years and 2 million years ( Permian or younger). The crater is buried beneath 75 to 200 feet (23–60 m) of glacial till and can only be seen as a series of faults and deformations in well logs and seismic surveys. Faulting in the structure has produced as much as of vertical displacement. Subsurface strata of Cambrian through Pennsylvanian age has been faulted and tilted by the event. The anomalous area was first noted by water well drillers in 1893, who noted an absence of water in a deep well. Prior to being recognized as an impact structure, the feature was referred to as a ''cryptoexplosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Preserve District Of Cook County
The Forest Preserve District of Cook County is a governmental commission in Cook County, Illinois, that owns and manages a network of open spaces, containing forest, prairie, wetland, streams, and lakes, that are mostly set aside as natural areas. Cook County contains Chicago, and is the center of the most densely populated urban metropolitan area in the Midwest. The Forest Preserve lands encompass approximately , about 11% of the county, providing open space within its urban surroundings. It contains facilities for recreation, as well as a zoo and a botanic garden. Background Most often being left more in their natural state, the Forest Preserves have a different purpose from urban parks; also they generally do not contain organized recreational facilities such as tennis courts or softball diamonds. They do contain hiking, bicycling, and riding trails, as well as facilities for nature and group activities, and they are heavily used for picnicking. They are administered by the F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection Seismology
Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite or Tovex blast, a specialized air gun or a seismic vibrator. Reflection seismology is similar to sonar and echolocation. This article is about surface seismic surveys; for vertical seismic profiles, see VSP. History Reflections and refractions of seismic waves at geologic interfaces within the Earth were first observed on recordings of earthquake-generated seismic waves. The basic model of the Earth's deep interior is based on observations of earthquake-generated seismic waves transmitted through the Earth's interior (e.g., Mohorovičić, 1910). The use of human-generated seismic waves to map in detail the geology of the upper few kilometers of the Earth's crust followed shortly thereafter and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of The United States
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *''Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from '' Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a student magazine for the University of Nottingham, England * '' Bathim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Illinois
The geology of Illinois includes extensive deposits of marine sedimentary rocks from the Palaeozoic, as well as relatively minor contributions from the Mesozoic and Cenozoic. Ice age glaciation left a wealth of glacial topographic features throughout the state. Precambrian Geology Precambrian rocks of Illinois are deeply buried by 2000–13000 feet (610–3960 m) of later sediments. Drilling has revealed these rocks to be primarily intrusive felsic igneous rocks, though some extrusive felsic rocks have also been recovered from boreholes. Precambrian rocks of Illinois are highly faulted; tectonic extension and related thermal subsidence have led to the formation of two major sedimentary basins. These basins, termed the Illinois Basin and Michigan Basin, allowed for extensive deposition of sedimentary rock during the Palaeozoic Era. The Illinois Basin is a northwest-southeast asymmetrical structural basin that is filled with more than 4000 meters of Paleozoic sedimentary rocks. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shatter Cone
Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the range of . Morphology Shatter cones have a distinctively conical shape that radiates from the top (''apex'') of the cones repeating cone-on-cone in large and small scales in the same sample. Sometimes they have more of a spoon shape on the side of a larger cone. In finer-grained rocks such as limestone, they form an easily recognizable "horsetail" pattern with thin grooves (''striae''). However, the word "striae" should not be used to describe shatter cones, as that is considered misleading. Coarser grained rocks tend to yield less well developed shatter cones, which may be difficult to distinguish from other geological formations such as slickensides. Geologists have various theories of what causes shatter cones to form, including compress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midwestern United States
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. It was officially named the North Central Region by the Census Bureau until 1984. It is between the Northeastern United States and the Western United States, with Canada to the north and the Southern United States to the south. The Census Bureau's definition consists of 12 states in the north central United States: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The region generally lies on the broad Interior Plain between the states occupying the Appalachian Mountain range and the states occupying the Rocky Mountain range. Major rivers in the region include, from east to west, the Ohio River, the Upper Mississippi River, and the Missouri River. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptoexplosion
In geology, a cryptoexplosion structure (or cryptovolcanic structure) is an explosion of unknown cause. The term is now largely obsolete. It was once commonly used to describe sites where there was geological evidence of a large-scale explosion within the Earth's crust, but no definitive evidence for the cause such as normal volcanic rocks. These sites are usually circular with signs of anomalous rock deformation contrasting with the surrounding region, and often showing evidence that crustal material had been uplifted and/or blown outwards. The assumption was that some unusual form of volcanism, or a gas explosion originating within the crust, was the cause. The use of the term went away with the rise of the science of impact crater recognition in the late 20th century. Most structures described as cryptoexplosions turned out to be eroded impact craters, caused by the impact of meteorites. Today geologists discount former cryptoexplosion theories. See also *Impact crater * Impact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSA Bulletin
The ''Geological Society of America Bulletin'' (until 1960 called ''The Bulletin of the Geological Society of America'' and also commonly referred to as ''GSA Bulletin'') is a peer-reviewed scientific journal that has been published by the Geological Society of America since 1890. Its first editor was William John McGee.Eckel, Edwin, 1982, GSA Memoir 155, The Geological Society of America — Life History of a Learned Society, p. 79., . According to the ''Journal Citation Reports'', the journal has a 2016 impact factor of 4.212. See also *List of scientific journals in earth and atmospheric sciences A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union ... References External links * Geological Society of America English-language journals Geology journals Bimonthly journals {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratum
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as either '' bedding surfaces'' or ''bedding planes''.Salvador, A. ed., 1994. ''International stratigraphic guide: a guide to stratigraphic classification, terminology, and procedure. 2nd ed.'' Boulder, Colorado, The Geological Society of America, Inc., 215 pp. . Prior to the publication of the International Stratigraphic Guide, older publications have defined a stratum as either being either equivalent to a single bed or composed of a number of beds; as a layer greater than 1 cm in thickness and constituting a part of a bed; or a general term that includes both ''bed'' and ''lamina''.Neuendorf, K.K.E., Mehl, Jr., J.P., and Jackson, J.A. , eds., 2005. ''Glossary of Geology'' 5th ed. Alexandria, Virginia, American Geological Institute. 779 pp. . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Displacement
In tectonics, vertical displacement refers to the shifting of land in a vertical direction, resulting in uplift and subsidence. The displacement of rock layers can provide information on how and why Earth's lithosphere changes throughout geologic time. There are different mechanisms which lead to vertical displacement such as tectonic activity, and isostatic adjustments. Tectonic activity leads to vertical displacement when crust is rearranged during a seismic event. Isostatic adjustments result in vertical displacement through sinking due to an increased load or isostatic rebound due to load removal. Tectonic causes of vertical displacement Vertical displacement resulting from tectonic activity occurs at divergent and convergent plate boundaries. The movement of magma in the asthenosphere can create divergent plate boundaries as the magma begins to rise and protrude weaker lithospheric crust. Subsidence at a divergent plate boundary is a form of vertical displacement which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
