Leseane_okstate_0664M_13248
... km. The deepest CPD values (16 to 23 km) occur within the cratons which have lithospheric thickness greater than 200 km. Within the orogenic mobile belts, the CPD estimates range between 15 and 17 km. The shallowest CPD values of 7 – 14 km occur beneath the ORZ. In the northeastern part of ORZ with ...
... km. The deepest CPD values (16 to 23 km) occur within the cratons which have lithospheric thickness greater than 200 km. Within the orogenic mobile belts, the CPD estimates range between 15 and 17 km. The shallowest CPD values of 7 – 14 km occur beneath the ORZ. In the northeastern part of ORZ with ...
Indentation of a continent with a built
... Morgan, 1968). Subduction zones are more or less asymmetric in profile. This is because subducting oceanic lithosphere is cold, dense and stiff compared to the leading edge of the non-subducting plate that accretes weak sediments in a cold hydraulic arc. More material is transferred across plate bou ...
... Morgan, 1968). Subduction zones are more or less asymmetric in profile. This is because subducting oceanic lithosphere is cold, dense and stiff compared to the leading edge of the non-subducting plate that accretes weak sediments in a cold hydraulic arc. More material is transferred across plate bou ...
Unit 1 The Ocean Basins
... According to fossil and rock records, oceans have existed on Earth for at least 3.8 billion years. It is easy to think that they are permanent features, ancient and unchanging. However, the only thing that is truly constant about ocean basins — and continents — is that they are always moving and cha ...
... According to fossil and rock records, oceans have existed on Earth for at least 3.8 billion years. It is easy to think that they are permanent features, ancient and unchanging. However, the only thing that is truly constant about ocean basins — and continents — is that they are always moving and cha ...
Released Items from the ATLAST Plate Tectonics Teacher Assessment
... E. Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day "fit" of the continents is less than perfect. F. Plate motion causes abutting plate ...
... E. Since the supercontinent Pangaea split up about 200 million years ago, the shapes of continents have been somewhat modified, mostly by erosion, sea level changes, and mountain-building; this is why the present-day "fit" of the continents is less than perfect. F. Plate motion causes abutting plate ...
PDF
... This simple story becomes more complicated when subcontinental lithosphere rather than asthenosphere is the mantle source (Carlson and others, 2005). Continental lithospheric mantle comprise stable “keels” that do not homogenize with time. This lithosphere tends to preserve the various geochemical f ...
... This simple story becomes more complicated when subcontinental lithosphere rather than asthenosphere is the mantle source (Carlson and others, 2005). Continental lithospheric mantle comprise stable “keels” that do not homogenize with time. This lithosphere tends to preserve the various geochemical f ...
Unit 1 The Ocean Basins
... open the Once and Future Oceans view. This view shows the present locations of today’s continents and oceans. However, the continents and oceans have not always been in these locations, nor will they be in the future. In this investigation, you will trace the movements of three continents from 750 m ...
... open the Once and Future Oceans view. This view shows the present locations of today’s continents and oceans. However, the continents and oceans have not always been in these locations, nor will they be in the future. In this investigation, you will trace the movements of three continents from 750 m ...
Receiver Functions of Seismic Waves in Layered Anisotropic Media
... splitting of the Ps phase was made by McNamara and Owens (1993). Further, how the seismic anisotropy influences the Ps phases on receiver functions was theoretically and observationally examined by subsequent studies (e.g., Levin and Park, 1997, 1998; Peng and Humphreys, 1997; Savage, 1998). These s ...
... splitting of the Ps phase was made by McNamara and Owens (1993). Further, how the seismic anisotropy influences the Ps phases on receiver functions was theoretically and observationally examined by subsequent studies (e.g., Levin and Park, 1997, 1998; Peng and Humphreys, 1997; Savage, 1998). These s ...
Trap thickness and the subtrappean structures related to
... Madagascar—moved over the Reunion hotspot during its northward journey (Morgan, 1981; Duncan and Pyle, 1988; Allegre et al., 1999). Geochronological studies have shown that the eruption of these massive amounts of lavas occurred rapidly over a period of only 1–4 million years (Courtillot et al., 198 ...
... Madagascar—moved over the Reunion hotspot during its northward journey (Morgan, 1981; Duncan and Pyle, 1988; Allegre et al., 1999). Geochronological studies have shown that the eruption of these massive amounts of lavas occurred rapidly over a period of only 1–4 million years (Courtillot et al., 198 ...
The deep subsurface biosphere in igneous ocean crust: frontier
... except in the immediately vicinity of recently emplaced magma or at high-temperature hydrothermal upflow zones. The thermal state of the upper crust as it moves away from seafloor spreading centers is highly variable, depending on factors such as the nature and rate of sedimentation, extent and freque ...
... except in the immediately vicinity of recently emplaced magma or at high-temperature hydrothermal upflow zones. The thermal state of the upper crust as it moves away from seafloor spreading centers is highly variable, depending on factors such as the nature and rate of sedimentation, extent and freque ...
10. Regional Geophysics and Structural Framework of the
... amount of shortening decreasing from their centers toward their plunging ends (Rohr, 1987). Anticlines are commonly asymmetric with their steep sides facing seaward. In the northern of the Vancouver Island margin drilling areas (Sites 889 and 890; MCS lines 85-02, 89-07, and 89-08), a single frontal ...
... amount of shortening decreasing from their centers toward their plunging ends (Rohr, 1987). Anticlines are commonly asymmetric with their steep sides facing seaward. In the northern of the Vancouver Island margin drilling areas (Sites 889 and 890; MCS lines 85-02, 89-07, and 89-08), a single frontal ...
Carbon Retention in Deeply Subducted Sedimentary Rocks
... shown for context. ...............................................................................................62 Appendix 6. Comparison of observed bulk δ13C values with values predicted for a closed-system model, where isotope ratios are controlled by exchange within the system rather than by e ...
... shown for context. ...............................................................................................62 Appendix 6. Comparison of observed bulk δ13C values with values predicted for a closed-system model, where isotope ratios are controlled by exchange within the system rather than by e ...
geophysical characterization of albian carbonates reservoirs
... The Albian carbonate reservoirs are good oil producers in many Brazilian basins along the continental margin. Most of these oil fields were discovered at least 40 years ago and today, it is observed a low oil production from them. The reason for this could be divided in two factors: the main reservo ...
... The Albian carbonate reservoirs are good oil producers in many Brazilian basins along the continental margin. Most of these oil fields were discovered at least 40 years ago and today, it is observed a low oil production from them. The reason for this could be divided in two factors: the main reservo ...
WalkerJ_JGR_95(B13)21483 - KU ScholarWorks
... Ulugh Muztagh flows are at the northernedge of a widely distributedfield of Plio-pliestocenevolcanic rocks in the north-central Tibetan Plateau. The crustally derived rocks described here are an endmember componentof a wide mixing zone of hybrid magmas; the other end-memberforms mantlederived, potas ...
... Ulugh Muztagh flows are at the northernedge of a widely distributedfield of Plio-pliestocenevolcanic rocks in the north-central Tibetan Plateau. The crustally derived rocks described here are an endmember componentof a wide mixing zone of hybrid magmas; the other end-memberforms mantlederived, potas ...
Continent–ocean transition and voluminous magmatic underplating
... Deep seismic refraction data were gathered across the entire East Greenland rifted margin north of the Jan Mayen Fracture Zone between 72◦ N and 75◦ N in 2003. Investigations of the deep crustal structure of this continental margin provide constraints on the formation of the margin and its structura ...
... Deep seismic refraction data were gathered across the entire East Greenland rifted margin north of the Jan Mayen Fracture Zone between 72◦ N and 75◦ N in 2003. Investigations of the deep crustal structure of this continental margin provide constraints on the formation of the margin and its structura ...
The Japan Trench and its juncture with the Kuril Trench" cruise
... measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the Leg 3) on the R / V "Jean Charcot". The main data acquired during the cruise, such as the Seabeam maps, m ...
... measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the Leg 3) on the R / V "Jean Charcot". The main data acquired during the cruise, such as the Seabeam maps, m ...
ARTICLE IN PRESS - Do plumes exist?
... The kinematics of subduction zones shows a variety of settings that can provide clues for dynamic understandings. Two reference frames are used here to describe the simple 2D kinematics of subduction zones. In the first, the upper plate is assumed fixed, whereas in the second frame upper and lower p ...
... The kinematics of subduction zones shows a variety of settings that can provide clues for dynamic understandings. Two reference frames are used here to describe the simple 2D kinematics of subduction zones. In the first, the upper plate is assumed fixed, whereas in the second frame upper and lower p ...
Acrobat PDF file - 1 Mb (text and Table 1)
... formed impregnated peridotites and hybrid troctolites, particularly abundant at Sites 1271 and 1275. Based on our limited sampling, it seems that focusing of melt transport into dunite conduits with sharp contacts against residual mantle peridotites, common in some ophiolites and perhaps beneath fas ...
... formed impregnated peridotites and hybrid troctolites, particularly abundant at Sites 1271 and 1275. Based on our limited sampling, it seems that focusing of melt transport into dunite conduits with sharp contacts against residual mantle peridotites, common in some ophiolites and perhaps beneath fas ...
Second Draft with Art and Photos September 2006
... large magnitude of 8.7. From the seismic records of the main quake and aftershocks, it is estimated that a fault surface 1,220 km in length slipped by as much as 10 m during the earthquake. The earthquake lasted over 8 minutes, an unusually long duration for an earthquake. The earthquake occurred at ...
... large magnitude of 8.7. From the seismic records of the main quake and aftershocks, it is estimated that a fault surface 1,220 km in length slipped by as much as 10 m during the earthquake. The earthquake lasted over 8 minutes, an unusually long duration for an earthquake. The earthquake occurred at ...
PDF
... Pb/204Pb, but have variable 207Pb/204Pb. Of the four Chilas samples that were analysed, two are from the Main Gabbronorites and two are from the UMA. UMA samples are cumulates, so it is difficult to infer much regarding their petrotectonic setting from their chemical compositions. The gabbronorite s ...
... Pb/204Pb, but have variable 207Pb/204Pb. Of the four Chilas samples that were analysed, two are from the Main Gabbronorites and two are from the UMA. UMA samples are cumulates, so it is difficult to infer much regarding their petrotectonic setting from their chemical compositions. The gabbronorite s ...
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.