Kinematic reconstruction of the Caribbean
... The Caribbean oceanic crust was formed west of the North and South American continents, probably from Late Jurassic through Early Cretaceous time. Its subsequent evolution has resulted from a complex tectonic history governed by the interplay of the North American, South American and (Paleo-)Pacific ...
... The Caribbean oceanic crust was formed west of the North and South American continents, probably from Late Jurassic through Early Cretaceous time. Its subsequent evolution has resulted from a complex tectonic history governed by the interplay of the North American, South American and (Paleo-)Pacific ...
Evolution of mantle plumes and uplift of continents during the
... lithosphere and asthenosphere vary in thickness. Hot mantle material reaching mid-ocean ridges solidifies, after which it moves horizontally, further cooling and forming the thickening oceanic lithosphere. As the lithosphere becomes heavier, the ocean floor deepens. On the contrary, the underlying a ...
... lithosphere and asthenosphere vary in thickness. Hot mantle material reaching mid-ocean ridges solidifies, after which it moves horizontally, further cooling and forming the thickening oceanic lithosphere. As the lithosphere becomes heavier, the ocean floor deepens. On the contrary, the underlying a ...
Bounds on the viscosity coefficient of continental lithosphere from
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
1_Activity_2_Sediments_blank
... to study marine sediments and the sea floor. The data it generated has greatly expanded the field of oceanography as well as our understanding of climate change, Earth history, marine resources, natural hazards, and the development and evolution of life. ODP began in 1985 as a US and international c ...
... to study marine sediments and the sea floor. The data it generated has greatly expanded the field of oceanography as well as our understanding of climate change, Earth history, marine resources, natural hazards, and the development and evolution of life. ODP began in 1985 as a US and international c ...
Molnar, P., and C. N. Garzione (2007), Bounds on the viscosity coefficient of continental lithosphere
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
Non-chondritic sulphur isotope composition of the terrestrial mantle
... depleted mantle is shown here to be significantly 34S-depleted with respect to chondrites. This low 34S/32S ratio has fundamental implications for our understanding of the origin and processes affecting moderately volatile elements in the terrestrial mantle. In the following, we use the 21.28 6 0.33 ...
... depleted mantle is shown here to be significantly 34S-depleted with respect to chondrites. This low 34S/32S ratio has fundamental implications for our understanding of the origin and processes affecting moderately volatile elements in the terrestrial mantle. In the following, we use the 21.28 6 0.33 ...
Mantle plumes and dynamics of the Earth interior — towards a new
... According to this theory, the cool lithospheric slabs, gravity-sinking in the upper mantle, cumulate at the 660 km boundary and, subsequently, episodically “breaking through” the boundary, they submerge towards the core/mantle boundary (CMB). High viscosity of the lower mantle, confirmed, among othe ...
... According to this theory, the cool lithospheric slabs, gravity-sinking in the upper mantle, cumulate at the 660 km boundary and, subsequently, episodically “breaking through” the boundary, they submerge towards the core/mantle boundary (CMB). High viscosity of the lower mantle, confirmed, among othe ...
PDF (Chapter 12. The Shape of the Earth, Heat Flow and Convection)
... A few places are markedly deep, notably the seafloor between Australia and Antarctica and the Argentine Basin of the South Atlantic. Other deep regions occur in the central Atlantic and the eastern Pacific and others, most notably south of India, are not so obvious because of deep sedimentary fill. ...
... A few places are markedly deep, notably the seafloor between Australia and Antarctica and the Argentine Basin of the South Atlantic. Other deep regions occur in the central Atlantic and the eastern Pacific and others, most notably south of India, are not so obvious because of deep sedimentary fill. ...
Future accreted terranes: a compilation of island arcs, oceanic
... of accretion, the FAT crust does not subduct completely, but instead builds out the accretionary wedge seaward, as in an accretionary plate margin (Clift and Vannucchi, 2004). Landward-verging imbricate thrust faults typically shear off blocks of tens to hundreds of meters of FAT or oceanic crust (K ...
... of accretion, the FAT crust does not subduct completely, but instead builds out the accretionary wedge seaward, as in an accretionary plate margin (Clift and Vannucchi, 2004). Landward-verging imbricate thrust faults typically shear off blocks of tens to hundreds of meters of FAT or oceanic crust (K ...
Author`s personal copy - Freie Universität Berlin
... rollback subduction of the Ligurian part of Alpine Tethys coincided with Western Alpine orogenesis and involved the formation of the Gibraltar and Calabrian arcs. Rapid subduction and arc formation were driven primarily by the pull of the gravitationally unstable, retreating Adriatic and African sla ...
... rollback subduction of the Ligurian part of Alpine Tethys coincided with Western Alpine orogenesis and involved the formation of the Gibraltar and Calabrian arcs. Rapid subduction and arc formation were driven primarily by the pull of the gravitationally unstable, retreating Adriatic and African sla ...
Reconciling plate-tectonic reconstructions of Alpine
... size of Alpine Tethys and the precise age of its demise. The gap in knowledge between plate-motion studies and field-based tectonic syntheses was large, primarily because modern structural petrology and geochronology were in their infancy and also because geologists were preoccupied with understandin ...
... size of Alpine Tethys and the precise age of its demise. The gap in knowledge between plate-motion studies and field-based tectonic syntheses was large, primarily because modern structural petrology and geochronology were in their infancy and also because geologists were preoccupied with understandin ...
Do fracture zones define continental margin segmentation
... eastern Atlantic, e.g. in their magmatic characteristics which vary, north to south, from volcanic (Rockall – Morgan et al., 1989) to nonvolcanic (Iberia – Dean et al., 2000; Congo-Zaire-Angola – Contrucci et al., 2004) to volcanic (Namibia – Bauer et al., 2000). However the nature of the along-stri ...
... eastern Atlantic, e.g. in their magmatic characteristics which vary, north to south, from volcanic (Rockall – Morgan et al., 1989) to nonvolcanic (Iberia – Dean et al., 2000; Congo-Zaire-Angola – Contrucci et al., 2004) to volcanic (Namibia – Bauer et al., 2000). However the nature of the along-stri ...
From Lithospheric Thickening and Divergent Collapse to Active
... processes, and allow investigation of the consequences of some theoretical processes. The numerical design involves building a simplified lithosphere whose vertical geometry changes under the action of four processes: (i) plane strain homogeneous deformation driven convergence, (ii) erosion/sediment ...
... processes, and allow investigation of the consequences of some theoretical processes. The numerical design involves building a simplified lithosphere whose vertical geometry changes under the action of four processes: (i) plane strain homogeneous deformation driven convergence, (ii) erosion/sediment ...
Burov, E., Lithosphere, mechanical properties, in
... lithological structure of lithosphere making it a stagnant layer. In contrast to viscous mantle, long-term rheology of the lithosphere is strongly influenced not only by its ductile but equally elastic and brittle properties. It is probably the nonviscous properties of the lithosphere that shape it ...
... lithological structure of lithosphere making it a stagnant layer. In contrast to viscous mantle, long-term rheology of the lithosphere is strongly influenced not only by its ductile but equally elastic and brittle properties. It is probably the nonviscous properties of the lithosphere that shape it ...
Magmatism at Rift Zones: The Generation of Volcanic Continental
... seismicvelocity of the igneousrocks eraplacedin the crust, from typically 6.8 km/s for normal mantle temperaturesto 7.2 km/s or higher. There is a concomitantdensityincrease.In the second part of the paper we review volcmaiccontinental margins and flood basalt provinces globally and show that they a ...
... seismicvelocity of the igneousrocks eraplacedin the crust, from typically 6.8 km/s for normal mantle temperaturesto 7.2 km/s or higher. There is a concomitantdensityincrease.In the second part of the paper we review volcmaiccontinental margins and flood basalt provinces globally and show that they a ...
Incipient shortening of a passive margin: the mechanical roles of
... In this paper we investigate post-break-up incipient shortening and thickening of passive margins, under the action of horizontal compression. One source of compression is ridge push. It results from the topographic effects of cooling and contraction of the oceanic lithosphere, away from an active s ...
... In this paper we investigate post-break-up incipient shortening and thickening of passive margins, under the action of horizontal compression. One source of compression is ridge push. It results from the topographic effects of cooling and contraction of the oceanic lithosphere, away from an active s ...
Extrapolating Oceanic Age Distributions
... Extrapolation of the age distribution of oceanic lithosphere has played a significant role in assessments of variations in global mean spreading rate, global mean ocean basin depth, and implications for global mean sea level. Subduction has already removed 50% of oceanic lithosphere younger than 55. ...
... Extrapolation of the age distribution of oceanic lithosphere has played a significant role in assessments of variations in global mean spreading rate, global mean ocean basin depth, and implications for global mean sea level. Subduction has already removed 50% of oceanic lithosphere younger than 55. ...
UHP metamorphism in garnet peridotite, Cuaba unit, Rio San Juan
... garnet, clinopyroxene, spinel, and corundum suggest pressures from 2.8 Gpa (810 °C) to 3.5 Gpa (740 °C). These high-P/T (UHP) conditions are at odds with other indications (1, 2, 4, above) for low-P/T conditions. The contradiction highlights the unusual character of the rocks, but may be consistent ...
... garnet, clinopyroxene, spinel, and corundum suggest pressures from 2.8 Gpa (810 °C) to 3.5 Gpa (740 °C). These high-P/T (UHP) conditions are at odds with other indications (1, 2, 4, above) for low-P/T conditions. The contradiction highlights the unusual character of the rocks, but may be consistent ...
Archean Geodynamics and the Thermal Evolution of Earth
... plate motion as predicted by the new model. Furthermore, the very fact of repeated continental aggregation indicates that thicker depleted lithosphere in the past needs to move more slowly to become negatively buoyant by thermal contraction and also needs to be strong enough to support resulting the ...
... plate motion as predicted by the new model. Furthermore, the very fact of repeated continental aggregation indicates that thicker depleted lithosphere in the past needs to move more slowly to become negatively buoyant by thermal contraction and also needs to be strong enough to support resulting the ...
Evidence for melting of garnet pyroxenite in the generation of
... Isotopic variations in mantle-derived melts are a primary source of information on the age, origin and magnitude of chemical heterogeneities in the convecting mantle. Understanding the relationship between the melting process and the generation and preservation of chemical heterogeneity in basaltic ...
... Isotopic variations in mantle-derived melts are a primary source of information on the age, origin and magnitude of chemical heterogeneities in the convecting mantle. Understanding the relationship between the melting process and the generation and preservation of chemical heterogeneity in basaltic ...
International Journal of Advanced Scientific and Technical Research
... Two contact zones were found in the study area. The first one exists between Ophiolite and Mithakhari sediment group. The second one exists in between Mithakhari and Andaman Flysch sediment group. Both of these contact zones were found to be vertical and smooth. The present study has clearly shown t ...
... Two contact zones were found in the study area. The first one exists between Ophiolite and Mithakhari sediment group. The second one exists in between Mithakhari and Andaman Flysch sediment group. Both of these contact zones were found to be vertical and smooth. The present study has clearly shown t ...
Three distinct types of hotspots in the Earth`s mantle
... Morgan [5] introduced the idea of a second type of hotspot island. Other authors as well [6^8] have elaborated on aspects of primary versus secondary hotspots. Most recently, Anderson [9,10] concluded that Morgan’s original deep plume model could be disproved. In his view, all non-plate boundary vol ...
... Morgan [5] introduced the idea of a second type of hotspot island. Other authors as well [6^8] have elaborated on aspects of primary versus secondary hotspots. Most recently, Anderson [9,10] concluded that Morgan’s original deep plume model could be disproved. In his view, all non-plate boundary vol ...
Mechanisms for the formation of ridge-axis topography at
... were treated as zero-strength cracks incapable of transmitting shear stresses; friction along the transform fault was not considered here. The crack elements have a very large aspect ratio (several kilometres long and a few hundred metres wide) and almost zero elastic strength of E=7×102 Pa compared ...
... were treated as zero-strength cracks incapable of transmitting shear stresses; friction along the transform fault was not considered here. The crack elements have a very large aspect ratio (several kilometres long and a few hundred metres wide) and almost zero elastic strength of E=7×102 Pa compared ...
Crustal structure of the French Guiana margin
... evolution of the French Guiana and Northeast Brazil continental margin, and to better understand the origin and development of along-margin segmentation. A 427-km-long combined multichannel reflection and wide-angle refraction seismic profile acquired across the southern French Guiana margin is inte ...
... evolution of the French Guiana and Northeast Brazil continental margin, and to better understand the origin and development of along-margin segmentation. A 427-km-long combined multichannel reflection and wide-angle refraction seismic profile acquired across the southern French Guiana margin is inte ...
Isostasy, flexure, and dynamic topography
... are frequently not available. Isostatic factors controlling lithospheric buoyancy are frequently uncertain and nonisostatic factors, such as lithospheric bending towards subduction zones and dynamic topography, are hard to distinguish. The question discussed here is whether a set of simple rules tha ...
... are frequently not available. Isostatic factors controlling lithospheric buoyancy are frequently uncertain and nonisostatic factors, such as lithospheric bending towards subduction zones and dynamic topography, are hard to distinguish. The question discussed here is whether a set of simple rules tha ...
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.