Newly identi¢ed segments of the Paci¢c^Australia plate boundary
... plates is roughly parallel to the plate boundary. This corresponding transform boundary segment, the North Fiji transform zone (NFTZ), is almost 1500 km long (Fig. 1). It represents one of the major transform boundaries on the Earth's surface [1] and has always been regarded as playing a major role ...
... plates is roughly parallel to the plate boundary. This corresponding transform boundary segment, the North Fiji transform zone (NFTZ), is almost 1500 km long (Fig. 1). It represents one of the major transform boundaries on the Earth's surface [1] and has always been regarded as playing a major role ...
Geological Society, London, Special Publications
... define the segmentation characteristics of this portion of the Indo-Australian-Antarctic plate boundary. The Southeast Indian Ridge within our survey area can be broken into three first-order segments bounded by one transform fault and two propagating rifts. The transform fault, located at the west ...
... define the segmentation characteristics of this portion of the Indo-Australian-Antarctic plate boundary. The Southeast Indian Ridge within our survey area can be broken into three first-order segments bounded by one transform fault and two propagating rifts. The transform fault, located at the west ...
Copyright © 2006, The Geological Society of America, Inc
... of the Apenninic-Maghrebian chain and the Afro-Adriatic continental crusts. From Quaternary times, the more pronounced slab retreat beneath the Calabrian arc with respect to the southern Apennines and Sicily produced a tearing of the crust through two transfer fault systems: the Vulcano line to the ...
... of the Apenninic-Maghrebian chain and the Afro-Adriatic continental crusts. From Quaternary times, the more pronounced slab retreat beneath the Calabrian arc with respect to the southern Apennines and Sicily produced a tearing of the crust through two transfer fault systems: the Vulcano line to the ...
GIS-based Reconstruction of Pangaea with Recent
... Ocean and is several times larger than the Tethys. - From a geological viewpoint these inland seas appear to be oceanic crust contained inside continental crust, and it is likely that they were connected to the Panthalassa Ocean by the sea. During the Permian period, about half of the Pangaean conti ...
... Ocean and is several times larger than the Tethys. - From a geological viewpoint these inland seas appear to be oceanic crust contained inside continental crust, and it is likely that they were connected to the Panthalassa Ocean by the sea. During the Permian period, about half of the Pangaean conti ...
Page 1 Ordovician orogeny in the Alps – a reappraisal Roger
... been different in those times. Furthermore, he mentions that unstable mineral compositions, typical for greywackes, could be linked to stream deposition during and following the intense stages of orogeny. Thus, greywackes are signs of terranes related to volcanism and perhaps to earlier stages of or ...
... been different in those times. Furthermore, he mentions that unstable mineral compositions, typical for greywackes, could be linked to stream deposition during and following the intense stages of orogeny. Thus, greywackes are signs of terranes related to volcanism and perhaps to earlier stages of or ...
The Statistical Upper Mantle Assemblage, Earth
... The geochemical diversity of mid-ocean ridge basalt (MORB) and oceanic island basalt (OIB) has traditionally been attributed to the existence of large-scale mantle heterogeneity, in particular to accessible reservoirs at various depths. However, reconciling the geochemical constraints for isolated, ...
... The geochemical diversity of mid-ocean ridge basalt (MORB) and oceanic island basalt (OIB) has traditionally been attributed to the existence of large-scale mantle heterogeneity, in particular to accessible reservoirs at various depths. However, reconciling the geochemical constraints for isolated, ...
Role of arc magmatism and lower crustal foundering
... the common Pb component. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) ...
... the common Pb component. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) ...
Tajika and Matsui - Rice Department of Earth Science
... accretion to the continents, metamorphism of carbonates followed by CO 2 degassmg through arc volcanism, carbon regassmg into the mantle, and CO 2 degasslng from the mantle. The degasslng rate of volatiles from the mantle is assumed to be proportional to the volatile concentration m the mantle multl ...
... accretion to the continents, metamorphism of carbonates followed by CO 2 degassmg through arc volcanism, carbon regassmg into the mantle, and CO 2 degasslng from the mantle. The degasslng rate of volatiles from the mantle is assumed to be proportional to the volatile concentration m the mantle multl ...
Diapirs as the source of the sediment signature in arc lavas
... produce slab-top temperatures above the fluid-saturated sediment solidus (>600–700 ◦ C at ≤3 GPa; refs 9,10), and H2 O/Ce and H2 O/K ratios in melt inclusions from arc lavas are consistent with fluid fluxed melting of sediments at 750◦ to more than 950 ◦ C beneath several global subduction systems11 ...
... produce slab-top temperatures above the fluid-saturated sediment solidus (>600–700 ◦ C at ≤3 GPa; refs 9,10), and H2 O/Ce and H2 O/K ratios in melt inclusions from arc lavas are consistent with fluid fluxed melting of sediments at 750◦ to more than 950 ◦ C beneath several global subduction systems11 ...
Relationship between bend‐faulting at trenches and intermediate
... occur in the cold parts of subducting slabs. However, the occurrence of earthquakes at depths >30 km is perplexing because there high confining pressure should inhibit brittle failure. A commonly invoked possible mechanism to overcome this is dehydration embrittlement [Raleigh and Paterson, 1965; Me ...
... occur in the cold parts of subducting slabs. However, the occurrence of earthquakes at depths >30 km is perplexing because there high confining pressure should inhibit brittle failure. A commonly invoked possible mechanism to overcome this is dehydration embrittlement [Raleigh and Paterson, 1965; Me ...
Hydrocarbon basins in SE Asia: understanding why they are there
... view the basins present two particular problems: exactly when did they begin to form and why? The two questions cannot be separated and it is not possible to identify a mechanism without knowing the timing. The abundance of basins suggests a major driving force should be identifiable. There are seve ...
... view the basins present two particular problems: exactly when did they begin to form and why? The two questions cannot be separated and it is not possible to identify a mechanism without knowing the timing. The abundance of basins suggests a major driving force should be identifiable. There are seve ...
Control of high oceanic features and subduction channel on
... 1877 northern Chile mega-thrust earthquakes (Comte and Pardo, 1991). The southern Peru 1868 rupture segment broke previously in 1604 and 1784 in a similar, approximately 450 km long rupture. The northwest part of that segment broke again in an Mw = 8.4 earthquake in 2001, filling at least partially t ...
... 1877 northern Chile mega-thrust earthquakes (Comte and Pardo, 1991). The southern Peru 1868 rupture segment broke previously in 1604 and 1784 in a similar, approximately 450 km long rupture. The northwest part of that segment broke again in an Mw = 8.4 earthquake in 2001, filling at least partially t ...
Polymetallic Sulphides - International Seabed Authority
... Several deposits are also known at the Mid-Atlantic Ridge but only one has so far been located at the ridge system of the Indian Ocean. The paucity of known sulphide deposits at the Mid-Atlantic Ridge and the Central Indian Ridge is largely explained by the fact that exploration in these areas has b ...
... Several deposits are also known at the Mid-Atlantic Ridge but only one has so far been located at the ridge system of the Indian Ocean. The paucity of known sulphide deposits at the Mid-Atlantic Ridge and the Central Indian Ridge is largely explained by the fact that exploration in these areas has b ...
here - GeoPRISMS
... processes and material cycles governed by subduction. It integrates and expands the former SEIZE and SubFac Initiatives, building on a growing recognition that the two systems are tightly linked and responding to many of the same forcing functions, although manifest in different ways. The SCD Initia ...
... processes and material cycles governed by subduction. It integrates and expands the former SEIZE and SubFac Initiatives, building on a growing recognition that the two systems are tightly linked and responding to many of the same forcing functions, although manifest in different ways. The SCD Initia ...
Proterozoic
... either due to an increase in oxygen or a more thorough mixing of the oceanic water column.[5] Red beds, which are colored by hematite, indicate an increase in atmospheric oxygen after 2 billion years ago; they are not found in older rocks.[5] The oxygen buildup was probably due to two factors: a fil ...
... either due to an increase in oxygen or a more thorough mixing of the oceanic water column.[5] Red beds, which are colored by hematite, indicate an increase in atmospheric oxygen after 2 billion years ago; they are not found in older rocks.[5] The oxygen buildup was probably due to two factors: a fil ...
Volcanoes and Igneous Activity Earth
... alterations from hot, ion-rich water • Regional metamorphism –Occurs during mountain building –Produces the greatest volume of metamorphic rock –Rocks usually display zones of contact and/or hydrothermal metamorphism ...
... alterations from hot, ion-rich water • Regional metamorphism –Occurs during mountain building –Produces the greatest volume of metamorphic rock –Rocks usually display zones of contact and/or hydrothermal metamorphism ...
Static and dynamic support of western United States
... The evaluation of crustal and lithospheric structure in light of seismological, gravity, and topography constraints can provide insights into the forces that drive tectonic deformation. One issue arising especially for continental plates is how much of the topographic signal is compensated by latera ...
... The evaluation of crustal and lithospheric structure in light of seismological, gravity, and topography constraints can provide insights into the forces that drive tectonic deformation. One issue arising especially for continental plates is how much of the topographic signal is compensated by latera ...
PDF (Chapter 8. Chemical Composition of the Mantle)
... of differentiation, or separation, processes. In some geochemical models it is assumed that large parts of the Earth escaped partial melting, or melt removal, and are therefore still "primitive." Some petrological models assume that melts being delivered to the Earth's surface are samples from previ ...
... of differentiation, or separation, processes. In some geochemical models it is assumed that large parts of the Earth escaped partial melting, or melt removal, and are therefore still "primitive." Some petrological models assume that melts being delivered to the Earth's surface are samples from previ ...
Erosion, Himalayan Geodynamics, and the Geomorphology of
... it is no coincidence that the two massifs occur within the syntaxial interiors. Rather, we think they owe their origin to rapid exhumation by great orogen-scale rivers (Indus and Tsangpo) as the rivers turn south and slice across the Himalaya. On the basis of the observations from Nanga Parbat summ ...
... it is no coincidence that the two massifs occur within the syntaxial interiors. Rather, we think they owe their origin to rapid exhumation by great orogen-scale rivers (Indus and Tsangpo) as the rivers turn south and slice across the Himalaya. On the basis of the observations from Nanga Parbat summ ...
A R T I C L E S - Geoscience Research Institute
... are not at all full of sediment; and in much of the deep oceanic abyssal plains, sediment thickness averages only a few hundred meters. It would take about 50 Ma to produce the generous estimate of 435 million km3 (Ronov & Yaroshevsky 1969) of sediment now found on the ocean and continental margins. ...
... are not at all full of sediment; and in much of the deep oceanic abyssal plains, sediment thickness averages only a few hundred meters. It would take about 50 Ma to produce the generous estimate of 435 million km3 (Ronov & Yaroshevsky 1969) of sediment now found on the ocean and continental margins. ...
Plate tectonics
Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός ""pertaining to building"") is a scientific theory that describes the large-scale motion of Earth's lithosphere. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. The geoscientific community accepted the theory after the concepts of seafloor spreading were later developed in the late 1950s and early 1960s.The lithosphere, which is the rigid outermost shell of a planet (on Earth, the crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight major plates (depending on how they are defined) and many minor plates. Where plates meet, their relative motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically varies from zero to 100 mm annually.Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some supporters) propose gradual shrinking (contraction) or gradual expansion of the globe.Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.