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Praia Grande Crater
Praia Grande crater is a diameter circular feature in the Santos Basin offshore Brazil. It is a possible impact crater that has been identified on 3D seismic by Petrobras in 2004. Further investigation is needed to obtain more information on the structure. The Russian Academy of Sciences lists the structure as a probable impact crater.Mikheeva, 2017 Description The Praia Grande crater is located in the Santos Basin, approximately southeast from the coastline of São Paulo State, Brazil. The identification of this structure is based on the interpretation of three-dimensional seismic data, acquired and processed in 2004 for petroleum exploration in a Petrobras concession block in the Santos Basin. The principal morphological elements, imposed on Upper Cretaceous rocks, are a structural high in the center of the crater, an adjacent ring syncline, and, externally, several concentric circular listric normal faults. The structure is apparently well preserved from erosion, measure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santos Basin
The Santos Basin ( pt, Bacia de Santos) is an approximately large mostly offshore sedimentary basin. It is located in the south Atlantic Ocean, some southeast of Santos, Brazil. The basin is one of the Brazilian basins to have resulted from the break-up of Gondwana since the Early Cretaceous, where a sequence of rift basins formed on both sides of the South Atlantic; the Pelotas, Santos, Campos and Espírito Santo Basins in Brazil, and the Namibia, Kwanza and Congo Basins in southwestern Africa. Santos Basin is separated from the Campos Basin to the north by the Cabo Frio High and the Pelotas Basin in the south by the Florianópolis High and the northwestern boundary onshore is formed by the Serra Do Mar coastal range. The basin is known for its thick layers of salt that have formed structures in the subsurface due to halokinesis. The basin started forming in the Early Cretaceous on top of the Congo Craton as a rift basin. The rift stage of the basin evolution combined with 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 compr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Brazil
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow 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 ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Impact Craters
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow 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 ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Possible Impact Craters On Earth
Possibility is the condition or fact of being possible. Latin origins of the word hint at ability. Possibility may refer to: * Probability, the measure of the likelihood that an event will occur * Epistemic possibility, a topic in philosophy and modal logic * Possibility theory, a mathematical theory for dealing with certain types of uncertainty and is an alternative to probability theory * Subjunctive possibility, (also called alethic possibility) is a form of modality studied in modal logic. ** Logical possibility, a proposition that will depend on the system of logic being considered, rather than on the violation of any single rule * Possible world, a complete and consistent way the world is or could have been Other *Possible (Italy), a political party in Italy * Possible Peru, a political party in Peru * Possible Peru Alliance, an electoral alliance in Peru Entertainment *''Kim Possible'', a US children's TV series :*Kim Possible (character), the central character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters Of Brazil
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] |
Santa Marta Crater
Santa Marta crater is a newly confirmed impact crater in Piauí State, northeastern Brazil. It is in diameter and it is estimated to have formed between 100 and 66 Ma, during the Late Cretaceous. Description Its impact origin was first proposed by S. Master and J. Heymann in 2000 based primarily on satellite remote sensing data and was confirmed more than a decade later after conclusive evidence of shock metamorphism such as breccia and shatter cones 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 rang ... were found.A. P. Crósta and M. A. Vasconcelos (2013)Confirmation Of The Impact Origin Of The Santa Marta Crater, Brazil 76th Annual Meteoritical Society Meeting See also * Umm al Binni lake References Impact craters of Brazil Cretaceous impact craters Cretaceous Bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Impact Craters In South America
This list includes all 11 confirmed impact craters in South America as listed in the Earth Impact Database. These features were caused by the collision of large meteorites or comets with the Earth. For eroded or buried craters, the stated diameter typically refers to an estimate of original rim diameter, and may not correspond to present surface features. Confirmed impact craters Unconfirmed impact craters The following craters are officially considered "unconfirmed" because they are not listed in the Earth Impact Database. Due to stringent requirements regarding evidence and peer-reviewed publication, newly discovered craters or those with difficulty collecting evidence generally are known for some time before becoming listed. However, entries on the unconfirmed list could still have an impact origin disproven. See also * Impact craters * Impact events * Bolides and Meteorites * Earth Impact Database – primary source * Traces of Catastrophe book from Lunar and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Possible Impact Structures On Earth
This is a list of possible impact structures on Earth. More than 130 geophysical features on the surface of the Earth have been proposed as candidate sites for impact events by appearing several times in the literature and/or being endorsed by the Impact Field Studies Group (IFSG) and/or Expert Database on Earth Impact Structures (EDEIS). For the purposes of this list and the List of impact craters on Earth, the terminology of "confirmed" as defined by the Earth Impact Database (EID) is considered authoritative. List of possible impact structures The following tables list geological features on Earth that some individuals have associated with impact events, but for which there is currently no confirming scientific evidence in the peer-reviewed literature. In order for a structure to be confirmed as an impact crater, it must meet a stringent set of well-established criteria. Some proposed impact structures are likely to eventually be confirmed, whereas others are likely to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Metamorphism
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions and the difficulty in reaching sufficient pressures during such an event. Effects Mineral microstructures Planar fractures Planar fractures are parallel sets of multiple planar cracks or cleavages in quartz grains; they develop at the lowest pressures characteristic of shock waves (~5–8 GPa) and a common feature of quartz grains found associated with impact structures. Although the occurrence of planar fractures is relatively common in other deformed rocks, the development of intense, widespread, and closely spaced planar fractures is considered diagnostic of shock metamorphism. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.Gradstein ''et al.'' (2004) Stratigraphic definition The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located. The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve '' Cladoceramus undulatoplicatus''. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012. The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid '' Marsup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A '' fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
