Dynamic Earth: crustal and mantle heterogeneity
... Research School of Earth Sciences, Australian National University, ACT 0200, Australia. The dynamic processes within the Earth leave their record in geophysical and geochemical variation about the general stratification with depth. A snapshot of current structure is provided by geophysical evidence, ...
... Research School of Earth Sciences, Australian National University, ACT 0200, Australia. The dynamic processes within the Earth leave their record in geophysical and geochemical variation about the general stratification with depth. A snapshot of current structure is provided by geophysical evidence, ...
Thermal evolution of the Earth as recorded by komatiites
... generation, and therefore provide important constraints on mantle conditions throughout Earth history. It is here that komatiites have played an important role, because their compositional characteristics have been used to trace mantle melting depths, temperatures and processes back into the Archean ...
... generation, and therefore provide important constraints on mantle conditions throughout Earth history. It is here that komatiites have played an important role, because their compositional characteristics have been used to trace mantle melting depths, temperatures and processes back into the Archean ...
Lecture 18
... lands also plot below the Hf-Nd isotope correlation. In addition, they have remarkably radiogenic Pb, with 206Pb/204Pb > 20. Following this kind of procedure, I found that oceanic basalts fall into 5 or so groups (White, 1985). It is reasonable to suppose that this reflects the existence of 5 reserv ...
... lands also plot below the Hf-Nd isotope correlation. In addition, they have remarkably radiogenic Pb, with 206Pb/204Pb > 20. Following this kind of procedure, I found that oceanic basalts fall into 5 or so groups (White, 1985). It is reasonable to suppose that this reflects the existence of 5 reserv ...
Physics of the Earth and Planetary Interiors Supercontinent
... between mantle plumes and plate tectonics, contrary to an earlier view that mantle plumes operate largely independent of plate tectonic processes (e.g., Hill et al., 1992). The large-scale (>6000 km) seismically slow anomalies below Africa and the Pacific led to suggestions of African and Pacific su ...
... between mantle plumes and plate tectonics, contrary to an earlier view that mantle plumes operate largely independent of plate tectonic processes (e.g., Hill et al., 1992). The large-scale (>6000 km) seismically slow anomalies below Africa and the Pacific led to suggestions of African and Pacific su ...
Dismantling the Deep Earth: Geochemical
... The observation that the mantle is heterogeneous leads to some of the most important questions in the study of the deep Earth: 1. How did the mantle become heterogeneous—how are the heterogeneities formed? 2. How old are the heterogeneities— how long do they survive? 3. At what length scales do the ...
... The observation that the mantle is heterogeneous leads to some of the most important questions in the study of the deep Earth: 1. How did the mantle become heterogeneous—how are the heterogeneities formed? 2. How old are the heterogeneities— how long do they survive? 3. At what length scales do the ...
Workman, Hart, 2005 - University of Maryland, Department of Geology
... ridge basalts (MORBs), which represents at least 30% the mass of the whole silicate Earth. A database for the chemical and physical properties of abyssal peridotites has become robust and complete enough to truly access a reference DMM. Using trace element depletion trends from the abyssal peridotit ...
... ridge basalts (MORBs), which represents at least 30% the mass of the whole silicate Earth. A database for the chemical and physical properties of abyssal peridotites has become robust and complete enough to truly access a reference DMM. Using trace element depletion trends from the abyssal peridotit ...
Three distinct types of hotspots in the Earth`s mantle
... There are on the order of 40 remaining, nonprimary hotspots. These do not have enough indications of a deep, lower mantle origin in our view. We will see below that they can themselves be subdivided into two groups, one of which may have a transition zone origin whereas the other would be much more ...
... There are on the order of 40 remaining, nonprimary hotspots. These do not have enough indications of a deep, lower mantle origin in our view. We will see below that they can themselves be subdivided into two groups, one of which may have a transition zone origin whereas the other would be much more ...
The Mantle and its Products
... considered an obstacle to slabs of oceanic lithosphere that had been subducted into the mantle, but evidence from seismic tomography (a technique in which seismic waves can be used to produce three-dimensional images of Earth’s interior) suggests that its role in acting as an impermeable barrier may ...
... considered an obstacle to slabs of oceanic lithosphere that had been subducted into the mantle, but evidence from seismic tomography (a technique in which seismic waves can be used to produce three-dimensional images of Earth’s interior) suggests that its role in acting as an impermeable barrier may ...
Radiogenic Isotope Geochemistry of the Mantle
... A principal objective of geology is to understand how the Earth evolved from its initial state to its present one. Radiogenic isotope geochemistry is uniquely suited for this sort of study because an isotope ratio such as 87Sr/86Sr is a function not only of the differentiation processes which fracti ...
... A principal objective of geology is to understand how the Earth evolved from its initial state to its present one. Radiogenic isotope geochemistry is uniquely suited for this sort of study because an isotope ratio such as 87Sr/86Sr is a function not only of the differentiation processes which fracti ...
American Journal of Science - gemoc
... of radiogenic heat sources. Decrease in the MgO content of komatiites.—The average MgO content of komatiites is one way to track the average eruptive temperature of the magma and of the mantle sources, which are likely mantle plumes (Arndt and others, 2008). Each point on figure 2 is the average MgO ...
... of radiogenic heat sources. Decrease in the MgO content of komatiites.—The average MgO content of komatiites is one way to track the average eruptive temperature of the magma and of the mantle sources, which are likely mantle plumes (Arndt and others, 2008). Each point on figure 2 is the average MgO ...
Impact origin for the greater Ontong Java Plateau?
... Geochemical similarities among Early Cretaceous tholeiites from the OJP, and the East Mariana and Nauru basins, have led to proposals for a common genetic origin, possibly by an OJP mantle plume [7,9]. Mesozoic magnetic anomalies in the basins indicate that Late Jurassic and Early Cretaceous oceanic ...
... Geochemical similarities among Early Cretaceous tholeiites from the OJP, and the East Mariana and Nauru basins, have led to proposals for a common genetic origin, possibly by an OJP mantle plume [7,9]. Mesozoic magnetic anomalies in the basins indicate that Late Jurassic and Early Cretaceous oceanic ...
A relatively reduced Hadean continental crust and - HAL
... Among the physical and chemical parameters used to characterize the Earth, oxidation state, as reflected by its prevailing oxygen fugacity (fO2), is a particularly important one. It controls many physicochemical properties and geological processes of the Earth’s different reservoirs, and affects the ...
... Among the physical and chemical parameters used to characterize the Earth, oxidation state, as reflected by its prevailing oxygen fugacity (fO2), is a particularly important one. It controls many physicochemical properties and geological processes of the Earth’s different reservoirs, and affects the ...
CT Science Center
... This package provides you and your students with pre visit, visit and post visit materials related to the topic of geologic forces. Specifically how do constructive and destructive forces shape the Earth’s surface? We have focused the investigations on how have those constructive and destructive for ...
... This package provides you and your students with pre visit, visit and post visit materials related to the topic of geologic forces. Specifically how do constructive and destructive forces shape the Earth’s surface? We have focused the investigations on how have those constructive and destructive for ...
Final Exam Study Guide File
... 54. Which of the following metamorphic rocks has a nonfoliated texture? a. slate c. marble b. gneiss d. schist REF: p. 83 OBJ: 3.14 Recognize foliated metamorphic rocks and describe how they form. MSC: application 55. Which of the following results when divergence occurs between two oceanic plates? ...
... 54. Which of the following metamorphic rocks has a nonfoliated texture? a. slate c. marble b. gneiss d. schist REF: p. 83 OBJ: 3.14 Recognize foliated metamorphic rocks and describe how they form. MSC: application 55. Which of the following results when divergence occurs between two oceanic plates? ...
Scholarly Interest Report
... Volcanic arcs at convergent plate margins account for roughly 25% of modern magmatism on the Earth. In addition, high volatile contents (mainly water) cause them to erupt in an explosive manner, and the volatile fluxes associated with this activity contribute significantly to greenhouse gases in th ...
... Volcanic arcs at convergent plate margins account for roughly 25% of modern magmatism on the Earth. In addition, high volatile contents (mainly water) cause them to erupt in an explosive manner, and the volatile fluxes associated with this activity contribute significantly to greenhouse gases in th ...
Earth and Planetary Science Letters Recycled crust in the
... then projected these values to 0 Ma (assuming a radiogenic ingrowth corresponding to the source parent/daughter ratios). This method allows for proper comparison of Quepos and CLIP lavas to the present day isotopic domains in the Galápagos archipelago. We tested the sensitivity of radiogenic source ...
... then projected these values to 0 Ma (assuming a radiogenic ingrowth corresponding to the source parent/daughter ratios). This method allows for proper comparison of Quepos and CLIP lavas to the present day isotopic domains in the Galápagos archipelago. We tested the sensitivity of radiogenic source ...
Recycled crust in the Galápagos Plume source at 70 Ma
... then projected these values to 0 Ma (assuming a radiogenic ingrowth corresponding to the source parent/daughter ratios). This method allows for proper comparison of Quepos and CLIP lavas to the present day isotopic domains in the Galápagos archipelago. We tested the sensitivity of radiogenic source ...
... then projected these values to 0 Ma (assuming a radiogenic ingrowth corresponding to the source parent/daughter ratios). This method allows for proper comparison of Quepos and CLIP lavas to the present day isotopic domains in the Galápagos archipelago. We tested the sensitivity of radiogenic source ...
Learning Outcome mapping of old spec to new
... changes in stress in rocks, changes in water levels in wells, changes in ground levels, magnetism and animal behaviour describe and explain the social consequences of attempted earthquake ...
... changes in stress in rocks, changes in water levels in wells, changes in ground levels, magnetism and animal behaviour describe and explain the social consequences of attempted earthquake ...
Linking collisional and accretionary orogens during Rodinia
... linked to the initiation of subduction and development of accretionary orogens around its periphery. Thus, breakup was a top-down instigated process. The locus of convergence was initially around northeastern and northern Laurentia in the early Neoproterozoic before extending to outboard of Amazonia ...
... linked to the initiation of subduction and development of accretionary orogens around its periphery. Thus, breakup was a top-down instigated process. The locus of convergence was initially around northeastern and northern Laurentia in the early Neoproterozoic before extending to outboard of Amazonia ...
The thermochemical structure and evolution of Earth`s mantle
... of depleted MORB mantle composition from a model of bulk-silicate-Earth composition: a signi cant fraction of the expected abundance of several elements is `missing’. This is consistent with the low concentrations of HPEs in the MORB source, which are insu¯ cient to explain the Earth’s heat ®ow, im ...
... of depleted MORB mantle composition from a model of bulk-silicate-Earth composition: a signi cant fraction of the expected abundance of several elements is `missing’. This is consistent with the low concentrations of HPEs in the MORB source, which are insu¯ cient to explain the Earth’s heat ®ow, im ...
Garzione, C. N., P. Molnar, J. C. Libarkin, and B, MacFadden (2006), Rapid Late Miocene rise
... which is consistent with high 3He/4He ratios across much of the Altiplano and Eastern Cordillera, interpreted to be reflect degassing of mantle-derived magmas [32]. Although the crustal column below the Western Cordillera magmatic arc shows typical highspeed lower crust, the crustal column below the ...
... which is consistent with high 3He/4He ratios across much of the Altiplano and Eastern Cordillera, interpreted to be reflect degassing of mantle-derived magmas [32]. Although the crustal column below the Western Cordillera magmatic arc shows typical highspeed lower crust, the crustal column below the ...
Grand Challenges in Geodynamics
... within our solar system and beyond. As a scientific discipline, geodynamics is distinguished from other Earth Science disciplines in that it usually starts from fundamental physical principles to interpret and predict Earth’s behavior, rather than working backwards from observations. Second, geodyna ...
... within our solar system and beyond. As a scientific discipline, geodynamics is distinguished from other Earth Science disciplines in that it usually starts from fundamental physical principles to interpret and predict Earth’s behavior, rather than working backwards from observations. Second, geodyna ...
Earth Science Learning Targets
... •Explain the difference between magma and lava. •Describe how volcanoes can affect can change the lithosphere. •Describe the difference between epicenter and focal point of an earthquake. •Compare plate boundary type with destruction of earthquake. •Explain how wave type determines magnitude of eart ...
... •Explain the difference between magma and lava. •Describe how volcanoes can affect can change the lithosphere. •Describe the difference between epicenter and focal point of an earthquake. •Compare plate boundary type with destruction of earthquake. •Explain how wave type determines magnitude of eart ...
PDF
... Plate tectonics is the horizontal motion of Earth’s thermal boundary layer (lithosphere) over the convecting mantle (asthenosphere) and is mostly driven by lithosphere sinking in subduction zones. Plate tectonics is an outstanding example of a self organizing, far from equilibrium complex system (SO ...
... Plate tectonics is the horizontal motion of Earth’s thermal boundary layer (lithosphere) over the convecting mantle (asthenosphere) and is mostly driven by lithosphere sinking in subduction zones. Plate tectonics is an outstanding example of a self organizing, far from equilibrium complex system (SO ...
Загрузить этот файл PDF - Геодинамика и тектонофизика
... such as rock lumps. They reflect primarily the degradation of megablocks as a result of their destruction due to high stresses in excess of the tensile strength of the medium. This group may also include blocks which formation is related to convection in the upper mantle layer, asthenosphere. Ther ...
... such as rock lumps. They reflect primarily the degradation of megablocks as a result of their destruction due to high stresses in excess of the tensile strength of the medium. This group may also include blocks which formation is related to convection in the upper mantle layer, asthenosphere. Ther ...