Resistivity Cross Section Through the Juan de Fuca Subduction
... geological or geophysical investigations have been incorporatedwherejustified. Our paper is divided into three major sections. First, we explain the approachtoward two-dimensionalmodeling. On land, the transversemagnetic (TM) impedancefunctionsare emphasizedbecausetheory and experienceshow that they ...
... geological or geophysical investigations have been incorporatedwherejustified. Our paper is divided into three major sections. First, we explain the approachtoward two-dimensionalmodeling. On land, the transversemagnetic (TM) impedancefunctionsare emphasizedbecausetheory and experienceshow that they ...
Mineralogy, geochemistry and geotectonic of plagiogranites from
... represents remnants of southern branch of Neo-Tethys Ocean in Iran, while plagiogranites from Shahre-Babak and Baft ophiolites, outcropping in Kerman and Yazd provinces, are located at the southwest margin of the central Iran microcontinental block (CIM) and northern branch of Neo-Tethys Ocean in Ir ...
... represents remnants of southern branch of Neo-Tethys Ocean in Iran, while plagiogranites from Shahre-Babak and Baft ophiolites, outcropping in Kerman and Yazd provinces, are located at the southwest margin of the central Iran microcontinental block (CIM) and northern branch of Neo-Tethys Ocean in Ir ...
Precambrian Research Geochemical and numerical constraints
... geochemical observations and numerical models. Based on a geochemical dataset of 295 granitoid samples from the Karelian and Kola cratons of the Fennoscandian Shield, we divide Neoarchean juvenile (extracted from oceanic crust or mantle) granitoids into three groups: (1) low-HREE (heavy rare earth e ...
... geochemical observations and numerical models. Based on a geochemical dataset of 295 granitoid samples from the Karelian and Kola cratons of the Fennoscandian Shield, we divide Neoarchean juvenile (extracted from oceanic crust or mantle) granitoids into three groups: (1) low-HREE (heavy rare earth e ...
2014-Wannamaker-Casc.. - University of Alberta
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
- Wiley Online Library
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
Evolution and diversity of subduction zones controlled by slab width
... lithosphere, and allows significant slab–plate coupling through the viscous bottom half to drive plate motion. The subducting plate is laterally homogeneous, thus ignoring trench-parallel buoyancy variation due to aseismic ridges/plateaus and change in lithospheric age, which affect trench geometry ...
... lithosphere, and allows significant slab–plate coupling through the viscous bottom half to drive plate motion. The subducting plate is laterally homogeneous, thus ignoring trench-parallel buoyancy variation due to aseismic ridges/plateaus and change in lithospheric age, which affect trench geometry ...
Cratons, mobile belts, alkaline rocks and
... Fig. 4. Idealized sections for a frontal collision of Himalayan-type between a craton and an active margin. Relations between rigidity of the plates and depth are represented left and right of the sections respectively for the craton and the active margin at the vertical of the numbered arrows. (A) ...
... Fig. 4. Idealized sections for a frontal collision of Himalayan-type between a craton and an active margin. Relations between rigidity of the plates and depth are represented left and right of the sections respectively for the craton and the active margin at the vertical of the numbered arrows. (A) ...
macpherson_hall_1999 Tectonic controls on arc magmatism
... is no reason why there should not be subduction zones characterised by hinge retreat, hinge advance and fixed hinges. However, Figure 2 shows that as far as SE Asia and the SW Pacific are concerned most subduction zones have indeed been retreating as Hamilton suggested. Future improvements in tecton ...
... is no reason why there should not be subduction zones characterised by hinge retreat, hinge advance and fixed hinges. However, Figure 2 shows that as far as SE Asia and the SW Pacific are concerned most subduction zones have indeed been retreating as Hamilton suggested. Future improvements in tecton ...
IgPetMORB13
... Approximately 60% of the surface of the Earth is composed of basalt or its gabbroic intrusive equivalent, which are composed largely of pyroxene and feldspar (< 50%). The oceanic crust averages about 6 km in thickness, but ranges from 0 km at mid-ocean ridges to 10 km near the continents. Ophiolites ...
... Approximately 60% of the surface of the Earth is composed of basalt or its gabbroic intrusive equivalent, which are composed largely of pyroxene and feldspar (< 50%). The oceanic crust averages about 6 km in thickness, but ranges from 0 km at mid-ocean ridges to 10 km near the continents. Ophiolites ...
Dynamics of intraoceanic subduction initiation
... modern ocean floor [e.g., Moores, 1982], the thickest magmatic crust found in ophiolites is 3 km [Nicolas et al., 2000]. Since the plate tectonic revolution, ophiolites have been recognized as on-land analogues of the oceanic lithosphere formed at mid-ocean ridges, until geochemical studies amassed ...
... modern ocean floor [e.g., Moores, 1982], the thickest magmatic crust found in ophiolites is 3 km [Nicolas et al., 2000]. Since the plate tectonic revolution, ophiolites have been recognized as on-land analogues of the oceanic lithosphere formed at mid-ocean ridges, until geochemical studies amassed ...
MORB13
... Approximately 60% of the surface of the Earth is composed of basalt or its gabbroic intrusive equivalent, which are composed largely of pyroxene and feldspar (< 50%). The oceanic crust averages about 6 km in thickness, but ranges from 0 km at mid-ocean ridges to 10 km near the continents. Ophiolites ...
... Approximately 60% of the surface of the Earth is composed of basalt or its gabbroic intrusive equivalent, which are composed largely of pyroxene and feldspar (< 50%). The oceanic crust averages about 6 km in thickness, but ranges from 0 km at mid-ocean ridges to 10 km near the continents. Ophiolites ...
ppt
... areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may post-date the thickening event by tens of millions of years. 2) Because the crust is solid in its normal state, some thermal disturbance is re ...
... areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may post-date the thickening event by tens of millions of years. 2) Because the crust is solid in its normal state, some thermal disturbance is re ...
there`s no place like home
... communities of fish. When undisturbed by fishing gear for many years, deep sea corals and sponges grow into elaborate gardens of increasing complexity, appeal, and ecological value. Fish seek out a series of these habitats throughout their life and at particular times of the year,75 seeking prey, sa ...
... communities of fish. When undisturbed by fishing gear for many years, deep sea corals and sponges grow into elaborate gardens of increasing complexity, appeal, and ecological value. Fish seek out a series of these habitats throughout their life and at particular times of the year,75 seeking prey, sa ...
A Paleoceanographic Reconstruction of the
... surface and deep water ocean conditions (Billups et al., 1998; Loutit et al., 1979; Zachos, 1993). Orbulina universa and Planulina wuellerstorfi (also classified under genus names Cibicides, Cibicidoides, and Fontbotia) are common planktonic and benthic genera, respectively, used in carbon and oxyge ...
... surface and deep water ocean conditions (Billups et al., 1998; Loutit et al., 1979; Zachos, 1993). Orbulina universa and Planulina wuellerstorfi (also classified under genus names Cibicides, Cibicidoides, and Fontbotia) are common planktonic and benthic genera, respectively, used in carbon and oxyge ...
Plastic photodegradation in the ocean
... because of the problems of extreme spatial heterogeneity, and the need to compare samples from equivalent water masses, which is to say that, if an examination of the same parcel of water a week apart is conducted, an order of magnitude change in plastic concentration could be observed.[11] Further, ...
... because of the problems of extreme spatial heterogeneity, and the need to compare samples from equivalent water masses, which is to say that, if an examination of the same parcel of water a week apart is conducted, an order of magnitude change in plastic concentration could be observed.[11] Further, ...
P R E L I M I N A R Y P R O O F S Unpublished Work © 2008 by
... Continents and Ocean Basins Have Significantly Different Properties and History. Within the uppermost portion of the mantle, near the surface of Earth our terminology becomes more complicated. For example, the cool, strong outermost layer of Earth is also called the lithosphere (lithos means “rock”) ...
... Continents and Ocean Basins Have Significantly Different Properties and History. Within the uppermost portion of the mantle, near the surface of Earth our terminology becomes more complicated. For example, the cool, strong outermost layer of Earth is also called the lithosphere (lithos means “rock”) ...
Marine Biology Research The fauna of
... smokers. They are also found on substrates completely covered by dense bacterial mats. Some cladorhizid sponges are known to harbour symbiothic methane-oxidizing bacteria and to utilize the enriched water surrounding the vents (Vacelet et al. 1996; Vacelet & Boury-Esnault 2002). In addition, these s ...
... smokers. They are also found on substrates completely covered by dense bacterial mats. Some cladorhizid sponges are known to harbour symbiothic methane-oxidizing bacteria and to utilize the enriched water surrounding the vents (Vacelet et al. 1996; Vacelet & Boury-Esnault 2002). In addition, these s ...
Plate Tectonics and Earthquakes
... The Father of Plate Tectonics John Tuzo Wilson was born in Ottawa in 1908, the first child of Henrietta Tuzo and John Armistead Wilson (Figure 3.5). His mother was an accomplished mountaineer and his father an engineer. This heritage was reflected by Tuzo Wilson’s choice of studies: he graduated fro ...
... The Father of Plate Tectonics John Tuzo Wilson was born in Ottawa in 1908, the first child of Henrietta Tuzo and John Armistead Wilson (Figure 3.5). His mother was an accomplished mountaineer and his father an engineer. This heritage was reflected by Tuzo Wilson’s choice of studies: he graduated fro ...
Author`s personal copy
... the common features of the crust and upper mantle structure throughout the whole investigated area, in particular, to trace the reference boundaries. The present paper continues the PNE data analysis and its key questions are the following: What are the general changes of the upper mantle velocity s ...
... the common features of the crust and upper mantle structure throughout the whole investigated area, in particular, to trace the reference boundaries. The present paper continues the PNE data analysis and its key questions are the following: What are the general changes of the upper mantle velocity s ...
North Atlantic and Arctic Region, Working Group 2
... habitats known and are associated with high local biodiversity. However, their remoteness and the relatively short history of ecological research mean that we have little information on how these ecosystems will fare in the face of predicted future climate change, and particularly ocean acidificatio ...
... habitats known and are associated with high local biodiversity. However, their remoteness and the relatively short history of ecological research mean that we have little information on how these ecosystems will fare in the face of predicted future climate change, and particularly ocean acidificatio ...
The Yellowstone Hotspot: Plume or Not?
... arise from boundary layers (i.e., the core-mantle boundary), oceanic lithosphere is thinner and easier to penetrate than continental lithosphere, and upper mantle flow beneath the interior of large tectonic plates should be simpler than at plate boundaries. The mantle plume model therefore works wel ...
... arise from boundary layers (i.e., the core-mantle boundary), oceanic lithosphere is thinner and easier to penetrate than continental lithosphere, and upper mantle flow beneath the interior of large tectonic plates should be simpler than at plate boundaries. The mantle plume model therefore works wel ...
1 Lecture 12 - What Controls the Composition of River Water and
... Mackenzie and Garrels, (1966) took another approach they wanted to explain how river water and its chemical load can turn into seawater. They compared the amount of material supplied to the ocean by rivers with the amount in the ocean and concluded that most of the elements have been replaced many t ...
... Mackenzie and Garrels, (1966) took another approach they wanted to explain how river water and its chemical load can turn into seawater. They compared the amount of material supplied to the ocean by rivers with the amount in the ocean and concluded that most of the elements have been replaced many t ...
Revised Tectonic Evolution of the Eastern Indian Ocean
... Many plume models also expect the massive initial magmatism to be coeval with continental break-up (e.g. Anderson, 1995; White and McKenzie, 1989). An interesting problem is how a single plume-head could result in the formation of a LIP such as the Kerguelen Plateau, proposed to have formed in burst ...
... Many plume models also expect the massive initial magmatism to be coeval with continental break-up (e.g. Anderson, 1995; White and McKenzie, 1989). An interesting problem is how a single plume-head could result in the formation of a LIP such as the Kerguelen Plateau, proposed to have formed in burst ...
the caribbean plate and the question of its formation
... some parts (Renne, et al., 1989). Cuba, Hispaniola, Puerto Rico and Virgin Island belong to that group of magmatic island arcs formed on oceanic crust. Subduction related magmatism occurred since the Middle Cretaceous to the Middle or Late Eocene. The Aves Ridge arc started its activity at the begin ...
... some parts (Renne, et al., 1989). Cuba, Hispaniola, Puerto Rico and Virgin Island belong to that group of magmatic island arcs formed on oceanic crust. Subduction related magmatism occurred since the Middle Cretaceous to the Middle or Late Eocene. The Aves Ridge arc started its activity at the begin ...
New Technological Developments for Oceanographic
... the European Multidisciplinary Seas Observatory (EMSO) have been developed in order to increase the capacity in the research, with the purpose of better understanding of physical, geological, chemical, ecological, biological and microbial processes, that take place in the oceans: from the surface do ...
... the European Multidisciplinary Seas Observatory (EMSO) have been developed in order to increase the capacity in the research, with the purpose of better understanding of physical, geological, chemical, ecological, biological and microbial processes, that take place in the oceans: from the surface do ...
Abyssal plain
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface. They are among the flattest, smoothest and least explored regions on Earth. Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills). In addition to these elements, active oceanic basins (those that are associated with a moving plate tectonic boundary) also typically include an oceanic trench and a subduction zone.Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. The creation of the abyssal plain is the end result of spreading of the seafloor (plate tectonics) and melting of the lower oceanic crust. Magma rises from above the asthenosphere (a layer of the upper mantle) and as this basaltic material reaches the surface at mid-ocean ridges it forms new oceanic crust. This is constantly pulled sideways by spreading of the seafloor. Abyssal plains result from the blanketing of an originally uneven surface of oceanic crust by fine-grained sediments, mainly clay and silt. Much of this sediment is deposited by turbidity currents that have been channelled from the continental margins along submarine canyons down into deeper water. The remainder of the sediment is composed chiefly of pelagic sediments. Metallic nodules are common in some areas of the plains, with varying concentrations of metals, including manganese, iron, nickel, cobalt, and copper. These nodules may provide a significant resource for future mining ventures.Owing in part to their vast size, abyssal plains are currently believed to be a major reservoir of biodiversity. The abyss also exerts significant influence upon ocean carbon cycling, dissolution of calcium carbonate, and atmospheric CO2 concentrations over timescales of 100–1000 years. The structure and function of abyssal ecosystems are strongly influenced by the rate of flux of food to the seafloor and the composition of the material that settles. Factors such as climate change, fishing practices, and ocean fertilization are expected to have a substantial effect on patterns of primary production in the euphotic zone. This will undoubtedly impact the flux of organic material to the abyss in a similar manner and thus have a profound effect on the structure, function and diversity of abyssal ecosystems.