Rhenium^Osmium Isotope and Platinum
... Marques et al., 2003). Furthermore, in contrast to the less than 200 Myr snapshot provided by ocean island basalts, LIP magmatism has occurred over much of Earth history, providing important constraints on the secular evolution of the terrestrial mantle. Here, we present a new major- and trace-eleme ...
... Marques et al., 2003). Furthermore, in contrast to the less than 200 Myr snapshot provided by ocean island basalts, LIP magmatism has occurred over much of Earth history, providing important constraints on the secular evolution of the terrestrial mantle. Here, we present a new major- and trace-eleme ...
20 Crystallization, Fractionation and Solidification of Co
... within them to flow or diffuse from one location to another. Crystals with large interfacial angles (>60 degrees) represent a near collapse of the grain-supported structure, which can act to either press out or lock melt fractions from one another within a crystal – a melt mush at lower temperatures ...
... within them to flow or diffuse from one location to another. Crystals with large interfacial angles (>60 degrees) represent a near collapse of the grain-supported structure, which can act to either press out or lock melt fractions from one another within a crystal – a melt mush at lower temperatures ...
The Architecture, Chemistry, and Evolution of - Cin
... All these batholiths are the products of the subduction of the Farallon plate and its derivatives under North America. The main batholithic segments, from south to north, are the Peninsular Ranges batholith (Baja California and southernmost California), the Sierra Nevada batholith and adjacent terra ...
... All these batholiths are the products of the subduction of the Farallon plate and its derivatives under North America. The main batholithic segments, from south to north, are the Peninsular Ranges batholith (Baja California and southernmost California), the Sierra Nevada batholith and adjacent terra ...
pdf version - Berkeley Seismological Laboratory
... observations [Chen, 1992; Dick et al., 2003; White et al., 1992]. The volume of oceanic crust is then calculated by multiplying the thickness of oceanic crust by the area of the seafloor at a given age, with the age of the seafloor determined from magnetic anomalies on the seafloor [M€ uller et al., 19 ...
... observations [Chen, 1992; Dick et al., 2003; White et al., 1992]. The volume of oceanic crust is then calculated by multiplying the thickness of oceanic crust by the area of the seafloor at a given age, with the age of the seafloor determined from magnetic anomalies on the seafloor [M€ uller et al., 19 ...
•Earthquakes and Tectonics •Rupture mechanics and modelling
... Seismic Hazard Map of Europe as part of the Global Seismic Hazard Map (Giardini et al., 2003; Grünthal et al., 1999). The map depicts the seismic hazard as Peak Ground Acceleration (PGA, ms-2) with 10% probability of exceedence (or a 90% chance of non-exceedance) in 50 years, corresponding to a retu ...
... Seismic Hazard Map of Europe as part of the Global Seismic Hazard Map (Giardini et al., 2003; Grünthal et al., 1999). The map depicts the seismic hazard as Peak Ground Acceleration (PGA, ms-2) with 10% probability of exceedence (or a 90% chance of non-exceedance) in 50 years, corresponding to a retu ...
Unusual nickel and copper to noble
... to high-MgO basalts but lower Pd/Ir ratios; there fore, on the Pd/Ir versus Ni/Cu plot, the Rån bogen samples plot below the high-MgO basalts, but still within the field of layered intrusions. The differences in the composition of the rocks from the three localities may be explained by olivine and ...
... to high-MgO basalts but lower Pd/Ir ratios; there fore, on the Pd/Ir versus Ni/Cu plot, the Rån bogen samples plot below the high-MgO basalts, but still within the field of layered intrusions. The differences in the composition of the rocks from the three localities may be explained by olivine and ...
Geological Society of America Bulletin
... Jackson and Thayer (1972) subsequently distinguished harzburgite-type versus lherzolitetype alpine peridotites. In this subgrouping, the harzburgite-type alpine peridotites represent the uppermost oceanic mantle, whereas the less-depleted lherzolite-type alpine peridotites correspond to the subconti ...
... Jackson and Thayer (1972) subsequently distinguished harzburgite-type versus lherzolitetype alpine peridotites. In this subgrouping, the harzburgite-type alpine peridotites represent the uppermost oceanic mantle, whereas the less-depleted lherzolite-type alpine peridotites correspond to the subconti ...
Tectonically asymmetric Earth - Dipartimento di Scienze della Terra
... moved relative to the pacific ones (e.g., Doubrovine et al., 2012). Pacific volcanic chains (e.g., Hawaii) are rather intraplate and independent to plate boundaries; therefore they better represent the motion of the plate with respect to the mantle source. On the other hand, Alpert et al. (2010), in t ...
... moved relative to the pacific ones (e.g., Doubrovine et al., 2012). Pacific volcanic chains (e.g., Hawaii) are rather intraplate and independent to plate boundaries; therefore they better represent the motion of the plate with respect to the mantle source. On the other hand, Alpert et al. (2010), in t ...
OBSERVATIONAL AND THEORETICAL STUDIES OF THE DYNAMICS OF MANTLE PLUME–MID-OCEAN RIDGE INTERACTION
... ratios in the source because isotopes of the same element have similar chemical behavior and do not fractionate during magma formation and migration. Furthermore, isotopes (e.g., 87Sr) with long parent half-lives (87Rb half-life is ⬃49 Gyr) do not grow significantly into the melt on the timescale of ...
... ratios in the source because isotopes of the same element have similar chemical behavior and do not fractionate during magma formation and migration. Furthermore, isotopes (e.g., 87Sr) with long parent half-lives (87Rb half-life is ⬃49 Gyr) do not grow significantly into the melt on the timescale of ...
Scandium mineralizations in southern Norway
... The calcite vein-fracture set is by Segalstad (1996) regarded as tension gashes which opened up as a response to shear movement along mylonite zones (locally called "rotten veins") which have their slip pointing south, possibly as a response to the Kongsberg block being tilted when it bent into the ...
... The calcite vein-fracture set is by Segalstad (1996) regarded as tension gashes which opened up as a response to shear movement along mylonite zones (locally called "rotten veins") which have their slip pointing south, possibly as a response to the Kongsberg block being tilted when it bent into the ...
`granitic` laver of the crust in the southern norwegian precambrian
... The highest levels of the southem Norwegian Precambrian are com posed of recognizable supracrustal rocks of intermediate density (chemical composition). Less dense migmatitic rocks whose origin is more obscure but whose layering is most likely inherited from original supracrustal rocks constitute t ...
... The highest levels of the southem Norwegian Precambrian are com posed of recognizable supracrustal rocks of intermediate density (chemical composition). Less dense migmatitic rocks whose origin is more obscure but whose layering is most likely inherited from original supracrustal rocks constitute t ...
AbdolnaserFazlnia-Word offic file
... and clinopyroxene change gradually. Where these contact boundaries are sharp, these changes are sharp. Anorthosites are composed mainly of plagioclase (Figure 4f) along with small percentages of olivine and clinopyroxene. Where the boundaries between these rocks and gabbro are gradational, changes i ...
... and clinopyroxene change gradually. Where these contact boundaries are sharp, these changes are sharp. Anorthosites are composed mainly of plagioclase (Figure 4f) along with small percentages of olivine and clinopyroxene. Where the boundaries between these rocks and gabbro are gradational, changes i ...
- ResearchOnline@JCU
... Where possible, unaltered samples were selected for Sr and Nd isotopic analyses. However, this was not always possible and the majority of samples were altered to some degree. Consequently, whole rock powders were leached in hot 6M HCl in a ultrasonicator followed by concentrated HNO3 on the hotplat ...
... Where possible, unaltered samples were selected for Sr and Nd isotopic analyses. However, this was not always possible and the majority of samples were altered to some degree. Consequently, whole rock powders were leached in hot 6M HCl in a ultrasonicator followed by concentrated HNO3 on the hotplat ...
Earth`s first two billion years—The era of internally
... over broad ranges, back to the local maximum age: the crustal material was repeatedly, if not continuously, near its solidus temperature for extremely long periods. No supracrustal rocks have been proved older than 3.6 Ga, from which I infer that not until that time were the ancient gneisses cool an ...
... over broad ranges, back to the local maximum age: the crustal material was repeatedly, if not continuously, near its solidus temperature for extremely long periods. No supracrustal rocks have been proved older than 3.6 Ga, from which I infer that not until that time were the ancient gneisses cool an ...
Exhumation of (ultra-)high-pressure terranes: concepts
... surface (Chopin, 1984; Smith, 1984; Sobolev and Shatsky, 1990). These reports prompted vigorous investigation into the physical processes that could be responsible for continental crustal subduction and exhumation. Terranes containing rocks metamorphosed to UHP conditions have now been documented fr ...
... surface (Chopin, 1984; Smith, 1984; Sobolev and Shatsky, 1990). These reports prompted vigorous investigation into the physical processes that could be responsible for continental crustal subduction and exhumation. Terranes containing rocks metamorphosed to UHP conditions have now been documented fr ...
SCIENCE CHINA Magmatism during continental collision
... requires the existence of prior oceanic subduction zone. It is generally assumed that the prerequisite of continental deep subduction is oceanic subduction and its drag force to the connecting passive-margin continental lithosphere during continental collision. Continental subduction and collision l ...
... requires the existence of prior oceanic subduction zone. It is generally assumed that the prerequisite of continental deep subduction is oceanic subduction and its drag force to the connecting passive-margin continental lithosphere during continental collision. Continental subduction and collision l ...
KENT C. CONDIE
... and graduate students in the Earth Sciences. The rapid accumulation of data on plate tectonics, mantle evolution, and the origin of continents in the last decade has necessitated continued updating of the course. The book is written for an advanced undergraduate or graduate student, and it assumes a ...
... and graduate students in the Earth Sciences. The rapid accumulation of data on plate tectonics, mantle evolution, and the origin of continents in the last decade has necessitated continued updating of the course. The book is written for an advanced undergraduate or graduate student, and it assumes a ...
Age of the Earth
The age of the Earth is 4.54 ± 0.05 billion years (4.54 × 109 years ± 1%). This age is based on evidence from radiometric age dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.Following the development of radiometric age dating in the early 20th century, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.The oldest such minerals analyzed to date—small crystals of zircon from the Jack Hills of Western Australia—are at least 4.404 billion years old. Comparing the mass and luminosity of the Sun to those of other stars, it appears that the Solar System cannot be much older than those rocks. Calcium-aluminium-rich inclusions – the oldest known solid constituents within meteorites that are formed within the Solar System – are 4.567 billion years old, giving an age for the solar system and an upper limit for the age of Earth.It is hypothesised that the accretion of Earth began soon after the formation of the calcium-aluminium-rich inclusions and the meteorites. Because the exact amount of time this accretion process took is not yet known, and the predictions from different accretion models range from a few millions up to about 100 million years, the exact age of Earth is difficult to determine. It is also difficult to determine the exact age of the oldest rocks on Earth, exposed at the surface, as they are aggregates of minerals of possibly different ages.