Continental crust generated in oceanic arcs
... oceanic crust that originally formed above the Galápagos mantle plume. We also find that seismic P-waves travel through the crust at velocities intermediate between those typically observed for oceanic and continental crust. We develop a continentality index to quantitatively correlate geochemical c ...
... oceanic crust that originally formed above the Galápagos mantle plume. We also find that seismic P-waves travel through the crust at velocities intermediate between those typically observed for oceanic and continental crust. We develop a continentality index to quantitatively correlate geochemical c ...
The origin and evolution of the Earth`s continental crust
... McCulloch & Bennett 1993). If about 60 per cent of the crust was in place by 2.6 Ae, a mean age of 2.4 Ae for the continental crust is obtained. ...
... McCulloch & Bennett 1993). If about 60 per cent of the crust was in place by 2.6 Ae, a mean age of 2.4 Ae for the continental crust is obtained. ...
Geologic Structures
... Some scientists have suggested that a nearby star exploded and the shock wave triggered the condensation. More than 90 percent of the matter in the cloud collapsed toward the center of the disk under the influence of gravity, forming the protosun. Collisions among highspeed particles released heat w ...
... Some scientists have suggested that a nearby star exploded and the shock wave triggered the condensation. More than 90 percent of the matter in the cloud collapsed toward the center of the disk under the influence of gravity, forming the protosun. Collisions among highspeed particles released heat w ...
Age, Origin and Emplacement of Diamonds
... which they crystallize, as well as the roclzs that brought them to the surface and in which they now are found as primary deposits. Clearly, such a broad survey is beyond the scope of this article. Therefore, we will focus on those aspects of diamond genesis that are of the greatest interest to gemo ...
... which they crystallize, as well as the roclzs that brought them to the surface and in which they now are found as primary deposits. Clearly, such a broad survey is beyond the scope of this article. Therefore, we will focus on those aspects of diamond genesis that are of the greatest interest to gemo ...
From oceanic plateaus to allochthonous terranes: Numerical
... plate beneath a continental margin on a lithospheric to upper mantle cross-section (4000 km by 1400 km) Fig. 1. The rectangular grid with 1361∗ 351 nodal points is non-uniform and contains a (1000 km wide) high-resolution area of 1 km ∗ 1 km in the centre of the domain. The rest of the model remains ...
... plate beneath a continental margin on a lithospheric to upper mantle cross-section (4000 km by 1400 km) Fig. 1. The rectangular grid with 1361∗ 351 nodal points is non-uniform and contains a (1000 km wide) high-resolution area of 1 km ∗ 1 km in the centre of the domain. The rest of the model remains ...
Relations between sedimentary basins and petroleum
... geodesy, earthquakes and magnetic anomalies for past movements. The flow of the plates, its westward polarization and the greater velocity of plates at low latitudes suggest that plate tectonics is influenced by the Earth’s rotation. The concentration of the mantle also seems to support this hypothe ...
... geodesy, earthquakes and magnetic anomalies for past movements. The flow of the plates, its westward polarization and the greater velocity of plates at low latitudes suggest that plate tectonics is influenced by the Earth’s rotation. The concentration of the mantle also seems to support this hypothe ...
nature ano evolution of the subcontinental mantle lithosphere below
... Ultramafic xenoliths found in the Pleistocene Pali-Aike alkali basalts, the southernmost outcropping of the Patagonian Plateau lavas of southern South America, inelude both garnet-bearing and garnet-free Iherzolites, harzburgites, and orthopyroxenites. Mineral geothermometry and geobarometry indicat ...
... Ultramafic xenoliths found in the Pleistocene Pali-Aike alkali basalts, the southernmost outcropping of the Patagonian Plateau lavas of southern South America, inelude both garnet-bearing and garnet-free Iherzolites, harzburgites, and orthopyroxenites. Mineral geothermometry and geobarometry indicat ...
SCIENCE CHINA Magmatism during continental collision
... Continental orogens on Earth can be classified into accretionary orogen and collisional orogen. Magmatism in orogens occurs in every periods of an orogenic cycle, from oceanic subduction, continental collision to orogenic collapse. Continental collision requires the existence of prior oceanic subduc ...
... Continental orogens on Earth can be classified into accretionary orogen and collisional orogen. Magmatism in orogens occurs in every periods of an orogenic cycle, from oceanic subduction, continental collision to orogenic collapse. Continental collision requires the existence of prior oceanic subduc ...
The Architecture, Chemistry, and Evolution of - Cin
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
... Below we describe the major subduction-related arcs of the Americas, other significant arcs in the geologic record, and some of the tilted sections that expose deeper segments of arcs. 2.4.1. Extinct arcs. The western North American Cordillera comprises a continuous belt of arc products (mostly intru ...
- Wiley Online Library
... [1] Physical properties of the mantle lithosphere have a strong influence on the rifting processes and rifted structures. In particular, in context of rifting, two of these properties have been overlooked: (1) Mohr-Coulomb plasticity (localizing pressure dependent) may not be valid at mantle depths a ...
... [1] Physical properties of the mantle lithosphere have a strong influence on the rifting processes and rifted structures. In particular, in context of rifting, two of these properties have been overlooked: (1) Mohr-Coulomb plasticity (localizing pressure dependent) may not be valid at mantle depths a ...
Kistufell: Primitive Melt from the Iceland Mantle
... (Hemond et al. 1993; Chauvel & Hemond, 2000). Identifying the source of these geochemical anomalies is not trivial, however. Although excess Sr and 18O-depletion in other ocean-island basalts (OIB) have been attributed to recycled oceanic crust in their mantle source (Lassiter & Hauri, 1998; Sobolev ...
... (Hemond et al. 1993; Chauvel & Hemond, 2000). Identifying the source of these geochemical anomalies is not trivial, however. Although excess Sr and 18O-depletion in other ocean-island basalts (OIB) have been attributed to recycled oceanic crust in their mantle source (Lassiter & Hauri, 1998; Sobolev ...
Synthesis of Results From the CD-ROM Experiment
... under the Archean (Dueker et al., 2001; Yuan and Dueker, this volume; Levander and Niu, 2004). The most plausible explanation for the north-dipping, high velocity, mantle anomaly is that it is an ancient slab fragment, for example a remnant of the rifted margin of the Wyoming Province (Tyson et al., ...
... under the Archean (Dueker et al., 2001; Yuan and Dueker, this volume; Levander and Niu, 2004). The most plausible explanation for the north-dipping, high velocity, mantle anomaly is that it is an ancient slab fragment, for example a remnant of the rifted margin of the Wyoming Province (Tyson et al., ...
joseph barrell - National Academy of Sciences
... "Those whom the gods love, die young." His period of educational preparation, balancing of personal characteristics, and storing dp of fundamental experiences was back of him. Had he lived longer he would have become the chief exponent in the subjects of geologic sedimentation, metamorphism, structu ...
... "Those whom the gods love, die young." His period of educational preparation, balancing of personal characteristics, and storing dp of fundamental experiences was back of him. Had he lived longer he would have become the chief exponent in the subjects of geologic sedimentation, metamorphism, structu ...
Volatile Cycling of H2O, CO2, F, and Cl in the HIMU Mantle: A New
... and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et al., 2011, 2014]. Alternatively, the high U/Pb inferred for the HIMU mantle source may be a result of U incorporation into oceanic crust during submarine alteration [Hart and Staudigel, 1982; Hofmann and Whi ...
... and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et al., 2011, 2014]. Alternatively, the high U/Pb inferred for the HIMU mantle source may be a result of U incorporation into oceanic crust during submarine alteration [Hart and Staudigel, 1982; Hofmann and Whi ...
Igneous Rock Associations 8. Arc Magmatism II: Geo
... In recent years, chemical studies of arc magmas have integrated data from major elements (those that typically comprise 0.1 wt % or higher), trace elements (less than 0.1 wt %), rare-earth elements (generally the “lanthanides”) and isotopes (typically RbSr, Sm-Nd and U-Pb systems). Important goals o ...
... In recent years, chemical studies of arc magmas have integrated data from major elements (those that typically comprise 0.1 wt % or higher), trace elements (less than 0.1 wt %), rare-earth elements (generally the “lanthanides”) and isotopes (typically RbSr, Sm-Nd and U-Pb systems). Important goals o ...
Hafnium isotope evidence for slab melt contributions in the Central
... 2005). It has also been shown that higher slab temperatures lead to increased silica polymerization and as a result, higher overall trace element mobility (Manning, 2004). Thus, high temperature silica-rich “slab-melts” can be traced by elements with limited mobility in low temperature aqueous- or s ...
... 2005). It has also been shown that higher slab temperatures lead to increased silica polymerization and as a result, higher overall trace element mobility (Manning, 2004). Thus, high temperature silica-rich “slab-melts” can be traced by elements with limited mobility in low temperature aqueous- or s ...
Magma genesis, plate tectonics, and chemical
... the solid mantle when partial melting occurs.The mantle and crust are both heterogeneous.Heterogeneitiesare produced in mantle peridotite by partial melting and extraction of melt, passage,or eraplacementof melt through or in mantle regions removed from the melt source, by the action of metasomatizi ...
... the solid mantle when partial melting occurs.The mantle and crust are both heterogeneous.Heterogeneitiesare produced in mantle peridotite by partial melting and extraction of melt, passage,or eraplacementof melt through or in mantle regions removed from the melt source, by the action of metasomatizi ...
2.03 Sampling Mantle Heterogeneity through Oceanic Basalts
... from the mantle are not in osmium-isotopic equilibrium with their source is given by the fact that osmium isotopes in MORBs are, on average, significantly more radiogenic than osmium isotopes from oceanic peridotites (see also Figure 9 further below). Although it may be argued that there is no one-t ...
... from the mantle are not in osmium-isotopic equilibrium with their source is given by the fact that osmium isotopes in MORBs are, on average, significantly more radiogenic than osmium isotopes from oceanic peridotites (see also Figure 9 further below). Although it may be argued that there is no one-t ...
Philippine Sea Plate inception, evolution, and consumption with
... We compiled the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent. We also analyzed the various explanatory models in light of this updated dataset. The following main conclusions are discussed in this study. (1) The Izanagi slab deta ...
... We compiled the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent. We also analyzed the various explanatory models in light of this updated dataset. The following main conclusions are discussed in this study. (1) The Izanagi slab deta ...
A2 Course Study Guide
... fixed composition will melt at higher temperatures than at lower pressures. And a ―wet‖ silicate (containing lots of volatiles) will melt (and freeze) at lower temperatures than a dry one. All these variables, coupled with polymerization, mean that when a rock is heated, it does not begin to melt at ...
... fixed composition will melt at higher temperatures than at lower pressures. And a ―wet‖ silicate (containing lots of volatiles) will melt (and freeze) at lower temperatures than a dry one. All these variables, coupled with polymerization, mean that when a rock is heated, it does not begin to melt at ...
34 - School of Ocean and Earth Science and Technology
... Because oceanic crust is relatively homogeneous, we can estimate its average composition through direct measurement of oceanic basalts. This is difficult to do with the continental crust, because it contains many different types of rocks. ...
... Because oceanic crust is relatively homogeneous, we can estimate its average composition through direct measurement of oceanic basalts. This is difficult to do with the continental crust, because it contains many different types of rocks. ...
Differentiation of the continental crust by relamination
... Crust extracted from the mantle in arcs is refined into continental crust in subduction zones. During sediment subduction, subduction erosion, arc subduction, and continent subduction, mafic rocks become eclogite and may sink into the mantle, whereas more silica-rich rocks are transformed into felsic ...
... Crust extracted from the mantle in arcs is refined into continental crust in subduction zones. During sediment subduction, subduction erosion, arc subduction, and continent subduction, mafic rocks become eclogite and may sink into the mantle, whereas more silica-rich rocks are transformed into felsic ...
Fluid Processes in Subduction Zones Hydrous Minerals and
... H2O Content of Arc Magmas • Significantly more H2O than MORBs, OIBs • Explosive eruptions (more H2O degassing, higher SiO2 content) • Hornblende (amphibole) is common phenocryst • H2O dramatically lowers melting T of rocks, mantle by 100s of degrees. key to arc magma genesis ...
... H2O Content of Arc Magmas • Significantly more H2O than MORBs, OIBs • Explosive eruptions (more H2O degassing, higher SiO2 content) • Hornblende (amphibole) is common phenocryst • H2O dramatically lowers melting T of rocks, mantle by 100s of degrees. key to arc magma genesis ...
Global tectonics - Scheme of work and lesson plan booklet
... OCR has produced an overview document, which summarises the changes to Geology. This can be found at www.ocr.org.uk, along with the new specification. In order to help you plan effectively for the implementation of the new specification we have produced this Scheme of Work and Sample Lesson Plans fo ...
... OCR has produced an overview document, which summarises the changes to Geology. This can be found at www.ocr.org.uk, along with the new specification. In order to help you plan effectively for the implementation of the new specification we have produced this Scheme of Work and Sample Lesson Plans fo ...