Evolution of the Tyrrhenian Sea-Calabrian Arc system: The past and
... alii, 1996; FACCENNA et alii, 2004; ROSENBAUM & LISTER, 2004). This explanation has a solid kinematic basis: if two plates do not converge significantly while subduction continues, the hinge of the subducting plate has to roll back, causing extension in the overriding plate. Conversely, if hinge mig ...
... alii, 1996; FACCENNA et alii, 2004; ROSENBAUM & LISTER, 2004). This explanation has a solid kinematic basis: if two plates do not converge significantly while subduction continues, the hinge of the subducting plate has to roll back, causing extension in the overriding plate. Conversely, if hinge mig ...
Crustal and Upper-mantle Structure Beneath Ice
... terrains in other continents where heat flow ranges from ∼41 to 58 mW m−2 , suggesting that heat flow across those areas of East Antarctica is not elevated. For the WARS, we use the Cretaceous Newfoundland–Iberia rifted margins and the Mesozoic-Tertiary North Sea rift as tectonic analogues. The low- ...
... terrains in other continents where heat flow ranges from ∼41 to 58 mW m−2 , suggesting that heat flow across those areas of East Antarctica is not elevated. For the WARS, we use the Cretaceous Newfoundland–Iberia rifted margins and the Mesozoic-Tertiary North Sea rift as tectonic analogues. The low- ...
A2 Course Study Guide
... One of the simplest crystal structures is that of sodium chloride (Na +Cl-). Here, the sodium and chloride ions are situated as if they were at the corners of cubes. Each sodium ion is surrounded by six chlorine ions and each chlorine ion is surrounded by six sodium ions. Minerals containing silico ...
... One of the simplest crystal structures is that of sodium chloride (Na +Cl-). Here, the sodium and chloride ions are situated as if they were at the corners of cubes. Each sodium ion is surrounded by six chlorine ions and each chlorine ion is surrounded by six sodium ions. Minerals containing silico ...
Mechanics of active magmatic intraplating in the Rio Grande Rift
... the latter is unlikely to be caused by hydrothermal activity. To establish whether the crustal uplift above the SMB indeed continues at a steady rate, and whether there is any variability in the uplift rate on shorter timescales (e.g., months to years), we requested the European Space Agency to resu ...
... the latter is unlikely to be caused by hydrothermal activity. To establish whether the crustal uplift above the SMB indeed continues at a steady rate, and whether there is any variability in the uplift rate on shorter timescales (e.g., months to years), we requested the European Space Agency to resu ...
Catastrophic Granite Formation Rapid Melting of
... or geophysical data. Thus it is now claimed that mechanical considerations suggest granite formation is a “rapid, dynamic process” operating at timescales of less than 100,000 years, or even only thousands of years. Magma Principles First, however, it will be helpful to explain what magma is and why ...
... or geophysical data. Thus it is now claimed that mechanical considerations suggest granite formation is a “rapid, dynamic process” operating at timescales of less than 100,000 years, or even only thousands of years. Magma Principles First, however, it will be helpful to explain what magma is and why ...
Chapter 11 SEDIMENTARY BASINS
... 7.1 The concept of geosynclines was developed in the last century to deal with the existence of thick successions of sedimentary rocks in what we would today call orogenic belts. A geosyncline is large troughlike or basinlike downwarping of the crust in which thick sedimentary and volcanic rocks acc ...
... 7.1 The concept of geosynclines was developed in the last century to deal with the existence of thick successions of sedimentary rocks in what we would today call orogenic belts. A geosyncline is large troughlike or basinlike downwarping of the crust in which thick sedimentary and volcanic rocks acc ...
An electrical resistivity model of the southeast Australian lithosphere
... With the exception of xenolith/xenocryst data (O’Reilly & Griffin 1985), geophysical surveys are the only means of investigating depths associated with the mid to lower crust and upper mantle. Gravity, magnetic, electromagnetic (EM) and reflection seismic (Brewer & Oliver 1980; Korsch et al. 2002) s ...
... With the exception of xenolith/xenocryst data (O’Reilly & Griffin 1985), geophysical surveys are the only means of investigating depths associated with the mid to lower crust and upper mantle. Gravity, magnetic, electromagnetic (EM) and reflection seismic (Brewer & Oliver 1980; Korsch et al. 2002) s ...
Structure of the crust beneath Cameroon, West Africa, from the joint
... A.-P. K. Tokam et al. straints. To make the contribution of each data set to the joint least-squares misfit comparable, a normalization of the data set is necessary, and this is done using the number of data points and variance for each of the data sets. An influence factor is used to control the tr ...
... A.-P. K. Tokam et al. straints. To make the contribution of each data set to the joint least-squares misfit comparable, a normalization of the data set is necessary, and this is done using the number of data points and variance for each of the data sets. An influence factor is used to control the tr ...
Author`s personal copy - School of Arts and Sciences
... ∼ 2.5 km ∼ 10–6 Ma and a slow and steady rise since ∼ 40 Ma. These end member models are evaluated by synthesizing observations of the AP lithosphere and the history of deformation, sedimentation, exhumation, magmatism, uplift, and fluvial incision. Structural and geophysical studies estimate variabl ...
... ∼ 2.5 km ∼ 10–6 Ma and a slow and steady rise since ∼ 40 Ma. These end member models are evaluated by synthesizing observations of the AP lithosphere and the history of deformation, sedimentation, exhumation, magmatism, uplift, and fluvial incision. Structural and geophysical studies estimate variabl ...
Crustal structure of the French Guiana margin
... crust is thinned by a factor of 6.4 over a distance of ∼70 km associated with continental breakup and the initiation and establishment of seafloor spreading. The ocean–continent boundary is a transition zone up to 45 km in width, in which the two-layered oceanic-type crustal structure develops. Alth ...
... crust is thinned by a factor of 6.4 over a distance of ∼70 km associated with continental breakup and the initiation and establishment of seafloor spreading. The ocean–continent boundary is a transition zone up to 45 km in width, in which the two-layered oceanic-type crustal structure develops. Alth ...
body waves tomography from obs-recorded earthquakes
... resolution P- and S-velocity distributions across the Gulf of Cadiz region. These velocity models are obtained using 3D seismic tomography to invert the OBS data-set. The results show that the patterns of anomalies in the Gulf of Cadiz are in general, oriented in NE-SW and NW-SE directions. They als ...
... resolution P- and S-velocity distributions across the Gulf of Cadiz region. These velocity models are obtained using 3D seismic tomography to invert the OBS data-set. The results show that the patterns of anomalies in the Gulf of Cadiz are in general, oriented in NE-SW and NW-SE directions. They als ...
Imaging igneous rocks on the North Atlantic rifted continental margin
... onto the northern slope of the Faroe-Shetland Basin. The velocities of the underlying sediment layer determined by Richardson et al. (1999) were, however, not well constrained due to a trade-off between velocity and thickness during modelling of the wide-angle seismic arrivals. Petrological argument ...
... onto the northern slope of the Faroe-Shetland Basin. The velocities of the underlying sediment layer determined by Richardson et al. (1999) were, however, not well constrained due to a trade-off between velocity and thickness during modelling of the wide-angle seismic arrivals. Petrological argument ...
IODP Proposal Cover Sheet
... The IODP Science Plan states that; ‘The creation and growth of continental crust remains one of the fundamental, unsolved problems in Earth science.’ The formation and evolution of the continental crust is a first order problem of terrestrial geochemistry because for many trace and minor elements, t ...
... The IODP Science Plan states that; ‘The creation and growth of continental crust remains one of the fundamental, unsolved problems in Earth science.’ The formation and evolution of the continental crust is a first order problem of terrestrial geochemistry because for many trace and minor elements, t ...
4.4 billion years of crustal maturation: oxygen isotope ratios of
... and preserves the most reliable record of both magmatic oxygen isotope ratio (d18O, Valley 2003) and magmatic age (U-Th-Pb, Hanchar and Hoskin 2003). Several factors combine in zircon to create a robust and retentive geochemical record, including: high temperatures of mineral stability and melting, ...
... and preserves the most reliable record of both magmatic oxygen isotope ratio (d18O, Valley 2003) and magmatic age (U-Th-Pb, Hanchar and Hoskin 2003). Several factors combine in zircon to create a robust and retentive geochemical record, including: high temperatures of mineral stability and melting, ...
The Architecture, Chemistry, and Evolution of Continental Magmatic
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
CHAPTER 4 GEOCHRONOLOGY AND ISOTOPIC CHARACTER OF
... there is no need to say “652 Ma old”. Ga numbers are an order of magnitude large than Ma numbers, and are used, mostly for convenience, in referring to Paleoproterozoic and Archean ages; an Archean age of 2750 Ma is the same as an age of 2.75 Ga. Geologic ages are measured back from the present time ...
... there is no need to say “652 Ma old”. Ga numbers are an order of magnitude large than Ma numbers, and are used, mostly for convenience, in referring to Paleoproterozoic and Archean ages; an Archean age of 2750 Ma is the same as an age of 2.75 Ga. Geologic ages are measured back from the present time ...
The role of crustal and mantle sources in the genesis of granitoids of
... source within Gondwana (Millar et al. in press). A few small granite bodies were intruded in eastern Graham Land at c. 400 Ma (Milne & Millar 1989): such granites have been identified elsewhere in the peninsula as clasts within conglomerates (Pankhurst 1983; Loske & Miller 1991; Tangeman et al. 1996 ...
... source within Gondwana (Millar et al. in press). A few small granite bodies were intruded in eastern Graham Land at c. 400 Ma (Milne & Millar 1989): such granites have been identified elsewhere in the peninsula as clasts within conglomerates (Pankhurst 1983; Loske & Miller 1991; Tangeman et al. 1996 ...
Igneous Environments
... of the magma erupted explosively, forming a turbulent cloud of pumice, volcanic ash, rock fragments, and hot, toxic gases that raced outward at speeds that likely exceeded hundreds of kilometers per hour. As magma escaped from the underground chamber, the roof of the chamber collapsed downward formi ...
... of the magma erupted explosively, forming a turbulent cloud of pumice, volcanic ash, rock fragments, and hot, toxic gases that raced outward at speeds that likely exceeded hundreds of kilometers per hour. As magma escaped from the underground chamber, the roof of the chamber collapsed downward formi ...
Ridge subduction and porphyry copper
... connected to adakites [4–6, 62, 63]. In China, the Tongling, Shaxi, Dexing porphyry or skarn Cu deposits are all associated with adakite or adakitic rocks [12, 46, 47, 64–66]. It has even been proposed that adakite should be taken as an exploration target for Cu deposits [67]. The genetic connection ...
... connected to adakites [4–6, 62, 63]. In China, the Tongling, Shaxi, Dexing porphyry or skarn Cu deposits are all associated with adakite or adakitic rocks [12, 46, 47, 64–66]. It has even been proposed that adakite should be taken as an exploration target for Cu deposits [67]. The genetic connection ...
The Architecture, Chemistry, and Evolution of - Cin
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
... subduction magmatism where the upper plate is continental and/or accreted transitional lithosphere. The active-type example is the Andean arc of South America. Well-studied deeply exhumed analogs to the Andean volcanic arc occur as composite batholiths along western North America. The South and Nort ...
Crustal structure of the central Sunda margin at the onset of oblique
... SO137-12 is located off southern Sumatra, approximately 75 km southeast of the island of Enggano (Fig. 2) and extends SW–NE from the Sunda trench to the Sumatra shelf. A second line (SO137-42) covers the subduction complex further southeast off Sunda Strait and extends about 250 km seawards of the t ...
... SO137-12 is located off southern Sumatra, approximately 75 km southeast of the island of Enggano (Fig. 2) and extends SW–NE from the Sunda trench to the Sumatra shelf. A second line (SO137-42) covers the subduction complex further southeast off Sunda Strait and extends about 250 km seawards of the t ...
EAST AFRICAN RIFT SYSTEM
... Barberi, F., Santacroce, R., and Varet, J., 1982: Chemical aspects of rift magmatism. In: Pálmason, G. (Ed.). Continental and oceanic rifts. AGU-GSA. Geodynamic series, Vol. 8, p. 223-258. Kebede, F., and Kulhánek, O., 1991: Recent seismicity of the East African Rift system and its implications. Phy ...
... Barberi, F., Santacroce, R., and Varet, J., 1982: Chemical aspects of rift magmatism. In: Pálmason, G. (Ed.). Continental and oceanic rifts. AGU-GSA. Geodynamic series, Vol. 8, p. 223-258. Kebede, F., and Kulhánek, O., 1991: Recent seismicity of the East African Rift system and its implications. Phy ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.