Mantle Mixing - Earth and Environmental Sciences
... than the layered mantle prediction. The third approach to determine the OIB source 3He concentration has focused on the relationship between 3He/4He and Pb-Nd-Sr isotopes. In the case of simple two component mixing between the plume source and depleted MORB mantle (DMM) the mixing constant K, for th ...
... than the layered mantle prediction. The third approach to determine the OIB source 3He concentration has focused on the relationship between 3He/4He and Pb-Nd-Sr isotopes. In the case of simple two component mixing between the plume source and depleted MORB mantle (DMM) the mixing constant K, for th ...
Hotspots and Melting Anomalies - Earth and Environmental Sciences
... An intriguing, yet enigmatic form of age-progressive volcanism is represented by the PukaPuka and Sojourn Ridges, which extend NW away from the East Pacific Rise. With respect to its geographic trend and duration, the Puka-Puka Ridge resembles some of the other volcano chains the region, such as the ...
... An intriguing, yet enigmatic form of age-progressive volcanism is represented by the PukaPuka and Sojourn Ridges, which extend NW away from the East Pacific Rise. With respect to its geographic trend and duration, the Puka-Puka Ridge resembles some of the other volcano chains the region, such as the ...
Plume heads, continental lithosphere, flood
... discontinuous LVZ extending NW from ·Ber- may be chemically distinct as well. It may, for muda to Iceland and Jan Mayan, This may be example, be the depleted reservoir and not well due to the continental edge effect, discussed by mixed with the shallow mantle. Much of the Vogt (1991) . He pointed ou ...
... discontinuous LVZ extending NW from ·Ber- may be chemically distinct as well. It may, for muda to Iceland and Jan Mayan, This may be example, be the depleted reservoir and not well due to the continental edge effect, discussed by mixed with the shallow mantle. Much of the Vogt (1991) . He pointed ou ...
science china - Woods Hole Oceanographic Institution
... hotspots and the SWIR and the ages of plateaus and seamounts through plate reconstruction. Employing bathymetric anomalies and the Airy isostasy model, we then calculated the magmatic volume of hotspots to (1) determine the origin and evolution of plateaus and seamounts in the study area and their r ...
... hotspots and the SWIR and the ages of plateaus and seamounts through plate reconstruction. Employing bathymetric anomalies and the Airy isostasy model, we then calculated the magmatic volume of hotspots to (1) determine the origin and evolution of plateaus and seamounts in the study area and their r ...
Origin of dipping structures in fast
... 39 800, Fig. 4) and Line 45 (CMP 32 100, Fig. 2a). Basement topography is substantially rougher for oceanic crust created at intermediate spreading rate, with variations of up to ∼800 m over distances of 1–14 km (Fig. 5a), similar to intermediate spreading crust elsewhere (e.g., Malinverno, 1991). F ...
... 39 800, Fig. 4) and Line 45 (CMP 32 100, Fig. 2a). Basement topography is substantially rougher for oceanic crust created at intermediate spreading rate, with variations of up to ∼800 m over distances of 1–14 km (Fig. 5a), similar to intermediate spreading crust elsewhere (e.g., Malinverno, 1991). F ...
Hawaii, Boundary Layers and Ambient
... controlled by processes and materials entirely in the upper boundary layer (5220 km depth) of the mantle rather than by deep-seated thermal instabilities. The upper boundary layer (BL) of the mantle is fertile enough, hot enough and variable enough to provide the observed range of temperatures and c ...
... controlled by processes and materials entirely in the upper boundary layer (5220 km depth) of the mantle rather than by deep-seated thermal instabilities. The upper boundary layer (BL) of the mantle is fertile enough, hot enough and variable enough to provide the observed range of temperatures and c ...
Crustal structure of the Hatton and the conjugate east Greenland
... [7] A vertical hydrophone array was deployed at the intersection point of the dip and strike lines (Figure 1), and used to calculate the waveform of the air gun source [Lunnon et al., 2003]. In order to produce a low-frequency, high-amplitude source capable of propagating long distances through the ...
... [7] A vertical hydrophone array was deployed at the intersection point of the dip and strike lines (Figure 1), and used to calculate the waveform of the air gun source [Lunnon et al., 2003]. In order to produce a low-frequency, high-amplitude source capable of propagating long distances through the ...
MANTLE MIXING - Earth and Environmental Sciences
... into the oceans (Lupton & Craig 1975, Farley et al. 1995), combined with the average production of basalt at ridges (Parsons 1981) and an assumption of the extent of MORB melting. An estimate of 20% partial melting at mid-oceanic ridges gives a MORB source mantle He concentration of 1.3 × 109 atoms ...
... into the oceans (Lupton & Craig 1975, Farley et al. 1995), combined with the average production of basalt at ridges (Parsons 1981) and an assumption of the extent of MORB melting. An estimate of 20% partial melting at mid-oceanic ridges gives a MORB source mantle He concentration of 1.3 × 109 atoms ...
Geophysical-petrological model of the crust and upper mantle in the
... thickness, and (iii) compare the calculated P and S velocity distributions in the upper mantle with published seismic tomography studies. ...
... thickness, and (iii) compare the calculated P and S velocity distributions in the upper mantle with published seismic tomography studies. ...
An olivine-free mantle source of Hawaiian shield basalts
... pyroxene persist6,8. Nickel concentrations in the melt are constrained even more strongly, because olivine has the highest partition coefficient for Ni of any mantle silicate. This coefficient depends strongly on melt composition, generally decreasing with increasing olivine component11 and sulphur ...
... pyroxene persist6,8. Nickel concentrations in the melt are constrained even more strongly, because olivine has the highest partition coefficient for Ni of any mantle silicate. This coefficient depends strongly on melt composition, generally decreasing with increasing olivine component11 and sulphur ...
Seismic Anisotropy of Subduction Zone Minerals–Contribution of
... pressure, and none related to hydrated mantle have been measured at elevated temperature. We have shown in the few cases where hydrous minerals have been measured as a function of pressure, that this variable has an important effect on the velocity distribution and in most cases reduces the degree o ...
... pressure, and none related to hydrated mantle have been measured at elevated temperature. We have shown in the few cases where hydrous minerals have been measured as a function of pressure, that this variable has an important effect on the velocity distribution and in most cases reduces the degree o ...
Supracrustal faults of the St. Lawrence rift system, Québec
... structures of basement rocks have influenced the development of the St. Lawrence rift faults, although it has been locally suggested (Lachapelle, 1993; Shaw, 1993). As in most extensional settings (e.g. Coletta et al., 1988; Ebinger, 1989; Schlische, 1993), it is likely the case but the structural p ...
... structures of basement rocks have influenced the development of the St. Lawrence rift faults, although it has been locally suggested (Lachapelle, 1993; Shaw, 1993). As in most extensional settings (e.g. Coletta et al., 1988; Ebinger, 1989; Schlische, 1993), it is likely the case but the structural p ...
Seismic characteristics and distribution of volcanic
... Identified sill reflections were described and mapped using the concept of seismic facies analysis, a method that was originally described by Vail & Mitchum (1977). Seismic facies analysis is the description and geological interpretation of seismic reflection parameters, including configuration, con ...
... Identified sill reflections were described and mapped using the concept of seismic facies analysis, a method that was originally described by Vail & Mitchum (1977). Seismic facies analysis is the description and geological interpretation of seismic reflection parameters, including configuration, con ...
Walla Walla County Hazard Identification and Vulnerability Analysis
... suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the fo ...
... suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the fo ...
`Azores Hotspot`a Wetspot?
... small temperature anomaly, are the key parameters to induce polybaric hydrous melting and fractionation that led Bonatti (1990) and Asimow et al. (2004) to question the concept of an Azores hotspot and the associated thermal anomaly. Alternative models propose the mantle partial melting beneath the ...
... small temperature anomaly, are the key parameters to induce polybaric hydrous melting and fractionation that led Bonatti (1990) and Asimow et al. (2004) to question the concept of an Azores hotspot and the associated thermal anomaly. Alternative models propose the mantle partial melting beneath the ...
SEARL MAGNETIC LIMITED. DOC-SISRC-SM-SMK-1.
... From that study, he accepted the Law of the Squares impression that there are two main states, and surely, one is random as he saw it as shown in figure 3.32.28 and the other was uniform as shown in figure 4.32.29. To Searl’s mind all things are at random state, cannot generate a force available for ...
... From that study, he accepted the Law of the Squares impression that there are two main states, and surely, one is random as he saw it as shown in figure 3.32.28 and the other was uniform as shown in figure 4.32.29. To Searl’s mind all things are at random state, cannot generate a force available for ...
LITHOSPHERIC STRUCTURE OF THE ARABIAN PLATE AND
... University. My sincere gratitude to the many people I met throughout my stay here at Cornell University and in other places who contributed in one way or another to this research. In particular, I am thankful to Alex Calvert, Christine Orgren Sandvol, Dogan Seber, Steve Gallow, Francisco Gomez, Carr ...
... University. My sincere gratitude to the many people I met throughout my stay here at Cornell University and in other places who contributed in one way or another to this research. In particular, I am thankful to Alex Calvert, Christine Orgren Sandvol, Dogan Seber, Steve Gallow, Francisco Gomez, Carr ...
Isostasy, dynamic topography, and the elevation of the Apennines of
... Constraints on the geodynamics of the Apennines come from observations of both topography and surface uplift rates. Topography data are readily available and can be directly compared to crustal and lithospheric density structure in order to differentiate between isostatic and dynamic sources (Royden ...
... Constraints on the geodynamics of the Apennines come from observations of both topography and surface uplift rates. Topography data are readily available and can be directly compared to crustal and lithospheric density structure in order to differentiate between isostatic and dynamic sources (Royden ...
Magnetotellurics
Magnetotellurics (MT) is an electromagnetic geophysical method for inferring the earth's subsurface electrical conductivity from measurements of natural geomagnetic and geoelectric field variation at the Earth's surface. Investigation depth ranges from 300m below ground by recording higher frequencies down to 10,000m or deeper with long-period soundings. Developed in the USSR and France during the 1950s, MT is now an international academic discipline and is used in exploration surveys around the world. Commercial uses include hydrocarbon (oil and gas) exploration, geothermal exploration, mining exploration, as well as hydrocarbon and groundwater monitoring. Research applications include experimentation to further develop the MT technique, long-period deep crustal exploration, and earthquake precursor prediction research.