An introduction to the special issue of Earth and Planetary Science
... mantle beneath the Reelfoot Rift, which may play a role in concentrating stress in the vicinity of the New Madrid Seismic Zone (NMSZ). Using high-resolution waveform modeling of records from the August 2011 Mineral, VA earthquake, Chu et al. (2014) also find evidence for low seismic velocities in the ...
... mantle beneath the Reelfoot Rift, which may play a role in concentrating stress in the vicinity of the New Madrid Seismic Zone (NMSZ). Using high-resolution waveform modeling of records from the August 2011 Mineral, VA earthquake, Chu et al. (2014) also find evidence for low seismic velocities in the ...
The Earth`s Shells, A. Thicknesses and Densities
... shells: an outermost crust, a thick shell called the mantle, and an interior core. You probably also learned that the outer core is liquid and the inner core is solid. ...
... shells: an outermost crust, a thick shell called the mantle, and an interior core. You probably also learned that the outer core is liquid and the inner core is solid. ...
Document
... Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered? A) Crystalline iron was found in lavas erupted from the deepest known hot spots. B) By analysis of the P-wave and S-wave shadow zones. C) Because P-wave speeds are higher in t ...
... Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered? A) Crystalline iron was found in lavas erupted from the deepest known hot spots. B) By analysis of the P-wave and S-wave shadow zones. C) Because P-wave speeds are higher in t ...
Revised history of Izanagi-Pacific ridge subduction
... rate of the Izanagi-Pacific plate pair from 118 Ma to 83 Ma cannot be determined directly. However, Late Jurassic to Early Cretaceous M-series magnetic anomalies in the west-central Pacific Ocean show no variation in spreading rate for at least 10 million years prior to the Cretaceous Normal Superch ...
... rate of the Izanagi-Pacific plate pair from 118 Ma to 83 Ma cannot be determined directly. However, Late Jurassic to Early Cretaceous M-series magnetic anomalies in the west-central Pacific Ocean show no variation in spreading rate for at least 10 million years prior to the Cretaceous Normal Superch ...
Author`s Personal Copy
... Mohorovicic discontinuity, while the band c axes are aligned perpendicular to a, either in distinct maxima or diffuse girdles. The ultramafics of many ophiolites have been subdivided into an upper cumulate section, which is considered genetically related to overlying cumulate gabbros [Thayer, 1969], ...
... Mohorovicic discontinuity, while the band c axes are aligned perpendicular to a, either in distinct maxima or diffuse girdles. The ultramafics of many ophiolites have been subdivided into an upper cumulate section, which is considered genetically related to overlying cumulate gabbros [Thayer, 1969], ...
The Farallon-Aluk ridge collision with South America: Implications
... convergence geometry and rates, ocean-floor topography, the arrival of active ocean ridges, and the fission of ocean plates. The continental counterpart in the active margin is subjected, in most cases, to compression during subduction and relaxation during transform episodes. In addition to the thick ...
... convergence geometry and rates, ocean-floor topography, the arrival of active ocean ridges, and the fission of ocean plates. The continental counterpart in the active margin is subjected, in most cases, to compression during subduction and relaxation during transform episodes. In addition to the thick ...
the Zero Paradox Noble Gas Mantle
... dependent on the 3He concentration of the convecting mantle derived from the 3He flux into the oceans and the average ocean crust generation rate. A factor of ~3.5 increase in the convecting mantle noble gas concentration removes all requirements for: i) a 3He flux into the upper mantle from a deepe ...
... dependent on the 3He concentration of the convecting mantle derived from the 3He flux into the oceans and the average ocean crust generation rate. A factor of ~3.5 increase in the convecting mantle noble gas concentration removes all requirements for: i) a 3He flux into the upper mantle from a deepe ...
The Lithosphere-Asthenosphere Boundary
... another factor, such as olivine grain size in the mantle, is varied ( Jackson et al. 2002, Faul & Jackson 2005). In mid-plate oceanic regions and beneath continents where mantle flow lacks a strong component of upwelling, temperature will increase over many tens of kilometers, and the vertical temper ...
... another factor, such as olivine grain size in the mantle, is varied ( Jackson et al. 2002, Faul & Jackson 2005). In mid-plate oceanic regions and beneath continents where mantle flow lacks a strong component of upwelling, temperature will increase over many tens of kilometers, and the vertical temper ...
Fore-arc basin
... Island arcs are of chains of volcanically active islands arranged in a curved arc An ocean trench occurs on the ocean-wards side Island arcs first develop on oceanic crust The crustal thickness in an arc is intermediate between oceanic and continental Volcanic activity begins abruptly at a Volcanic ...
... Island arcs are of chains of volcanically active islands arranged in a curved arc An ocean trench occurs on the ocean-wards side Island arcs first develop on oceanic crust The crustal thickness in an arc is intermediate between oceanic and continental Volcanic activity begins abruptly at a Volcanic ...
GLOBAL VARIATIONS IN THE LITHOSPHERIC THICKNESS ON
... of 0.5 to 1 billion years. However, if the planet is simply allowed to conductively cool, the lithosphere would continue to thicken and at some point it would either grow to a depth where the temperature profile no longer intersects the solidus or to a depth below the melt density inversion and all ...
... of 0.5 to 1 billion years. However, if the planet is simply allowed to conductively cool, the lithosphere would continue to thicken and at some point it would either grow to a depth where the temperature profile no longer intersects the solidus or to a depth below the melt density inversion and all ...
Adakitic magmas: modern analogues of Archaean granitoids
... Both geochemical and experimental petrological research indicate that Archaean continental crust was generated by partial melting of an Archaean tholeiite transformed into a garnet-bearing amphibolite or eclogite. The geodynamic context of tholeiite melting is the subject of controversy. It is assum ...
... Both geochemical and experimental petrological research indicate that Archaean continental crust was generated by partial melting of an Archaean tholeiite transformed into a garnet-bearing amphibolite or eclogite. The geodynamic context of tholeiite melting is the subject of controversy. It is assum ...
Plate Tectonics Questions
... 45. During which geologic period were the continents all part of one landmass, with North America and South America joined to Africa? A) Tertiary C) Triassic ...
... 45. During which geologic period were the continents all part of one landmass, with North America and South America joined to Africa? A) Tertiary C) Triassic ...
Coupled and decoupled regimes of continental collision: Numerical
... channel triggering complete decoupling of two plates, mantle wedging into the crustal wedge and retreating style of collision. The evolution of fully decoupled collision zones are characterized by the disruption of the accretionary wedge, formation of an extensional basin in the inner part of the or ...
... channel triggering complete decoupling of two plates, mantle wedging into the crustal wedge and retreating style of collision. The evolution of fully decoupled collision zones are characterized by the disruption of the accretionary wedge, formation of an extensional basin in the inner part of the or ...
Constraining the extent of crust–mantle coupling in central Asia
... dynamics that control crustal motions. On the other hand, if the upper mantle is strong relative to the seismogenic crust, and there is lithospheric coupling, then body and boundary forces applied to the mantle portion of the lithosphere will have a dominant control and signature on the surface defo ...
... dynamics that control crustal motions. On the other hand, if the upper mantle is strong relative to the seismogenic crust, and there is lithospheric coupling, then body and boundary forces applied to the mantle portion of the lithosphere will have a dominant control and signature on the surface defo ...
Felsitic Magmatism and Thorium - Bismuth Ore Mineralization in the
... Petrochemical studying of the rocks corresponds to depleted in alumina, acid igneous rocks in which CNK>A>NK and are genetically related to subduction zones and localized in islandarc complexes. Parameter A/CNK in all formations is less than one, which may indicate their mantle origin and formation ...
... Petrochemical studying of the rocks corresponds to depleted in alumina, acid igneous rocks in which CNK>A>NK and are genetically related to subduction zones and localized in islandarc complexes. Parameter A/CNK in all formations is less than one, which may indicate their mantle origin and formation ...
Chapter 5: Earthquakes
... Types of Seismic Waves • Waves race out from the focus of an earthquake. • The point on the surface directly above the focus is the epicenter. • Three types of seismic waves: – P Waves: 1st waves to arrive, compress and expand ground like an accordion, travel through liquids and solids; damage buil ...
... Types of Seismic Waves • Waves race out from the focus of an earthquake. • The point on the surface directly above the focus is the epicenter. • Three types of seismic waves: – P Waves: 1st waves to arrive, compress and expand ground like an accordion, travel through liquids and solids; damage buil ...
The Task
... Seafloor spreading: summarize how Seafloor Spreading creates new crust and select appropriate media on Discoveryeducation.com to accompany that summary. Where does seafloor spreading occur (at what type of plate boundary?) How is new crust made? How do scientists study seafloor spreading? Hist ...
... Seafloor spreading: summarize how Seafloor Spreading creates new crust and select appropriate media on Discoveryeducation.com to accompany that summary. Where does seafloor spreading occur (at what type of plate boundary?) How is new crust made? How do scientists study seafloor spreading? Hist ...
Melting of the Uppermost Metasomatized Asthenosphere Triggered
... attractive model, recent studies have focused more on the roles of fluids released from a subducted slab of Pacific lithosphere. These have been inspired by the progress of seismic tomography, which has revealed the existence of a stagnant slab extending continuously from the subducting Pacific plat ...
... attractive model, recent studies have focused more on the roles of fluids released from a subducted slab of Pacific lithosphere. These have been inspired by the progress of seismic tomography, which has revealed the existence of a stagnant slab extending continuously from the subducting Pacific plat ...
EarthComm 8.1
... examined the This Dynamic Planet map. You saw that different parts of the geosphere can have vast differences in age. The oldest oceanic crust is not older than 200 million years. However, continental rocks are much older. They tell a longer history of the geosphere. ...
... examined the This Dynamic Planet map. You saw that different parts of the geosphere can have vast differences in age. The oldest oceanic crust is not older than 200 million years. However, continental rocks are much older. They tell a longer history of the geosphere. ...
Trace element and isotope geochemistry of gabbro
... enrichment which reflect relatively high amphibole amounts. The samples with the highest mg# have a marked positive Eu anomaly, which is coupled with spikes at Sr and Ba in the chondrite-normalized patterns of incompatible elements. The gabbroderived granulites with the lowest mg# are characterized ...
... enrichment which reflect relatively high amphibole amounts. The samples with the highest mg# have a marked positive Eu anomaly, which is coupled with spikes at Sr and Ba in the chondrite-normalized patterns of incompatible elements. The gabbroderived granulites with the lowest mg# are characterized ...
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.