Canada`s craton: A bottoms-up view
... the mantle beneath Archean crustal provinces. Where it does occur, it may be a heterogeneous feature possibly imparted by marine weathering of peridotite on the Archean ocean floor before it was stacked to form a mantle root. ...
... the mantle beneath Archean crustal provinces. Where it does occur, it may be a heterogeneous feature possibly imparted by marine weathering of peridotite on the Archean ocean floor before it was stacked to form a mantle root. ...
Densities of metapelitic rocks at high to ultrahigh
... function of rock composition and P–T conditions. For that reason, we have intended to fill this gap using internally-consistent thermodynamic data sets of rockforming minerals including their solid solution properties. These calculations were undertaken for the critical P–T range N10 kbar, N600 °C w ...
... function of rock composition and P–T conditions. For that reason, we have intended to fill this gap using internally-consistent thermodynamic data sets of rockforming minerals including their solid solution properties. These calculations were undertaken for the critical P–T range N10 kbar, N600 °C w ...
Density constraints on the formation of the continental Moho and crust
... and lower crustal columns reviewed by Fountain and Salisbury (1981) point to the overall importance of a magma underplating model. Common to the cross-sections at the Invrea Zone, Fraser and Musgrave Range, Pikwitonei Belt, and the Kasila Series is a change in metamorphic grade from the granulite fa ...
... and lower crustal columns reviewed by Fountain and Salisbury (1981) point to the overall importance of a magma underplating model. Common to the cross-sections at the Invrea Zone, Fraser and Musgrave Range, Pikwitonei Belt, and the Kasila Series is a change in metamorphic grade from the granulite fa ...
Factors influencing magmatism during continental break
... thick, less than half that typically seen at other volcanic margins. The continent-ocean transition zone ...
... thick, less than half that typically seen at other volcanic margins. The continent-ocean transition zone ...
Key - Scioly.org
... 50. Why was the marine chronometer such an important development in navigation? It allows for the calculation of longitude on a ship at sea 51. List three sources of salt in the ocean. (3 points) • Gradual processes such as breaking up of cooled igneous rocks of Earth’s crust by weathering and erosi ...
... 50. Why was the marine chronometer such an important development in navigation? It allows for the calculation of longitude on a ship at sea 51. List three sources of salt in the ocean. (3 points) • Gradual processes such as breaking up of cooled igneous rocks of Earth’s crust by weathering and erosi ...
Chapter 5
... by dust and gravel, silt and mud. This sediment includes particles from land, from biological activity in the ocean, from chemical processes within water, and even from space. Analysis of this sedimentary material can tell us the recent history of an ocean basin, and sometimes the recent history of ...
... by dust and gravel, silt and mud. This sediment includes particles from land, from biological activity in the ocean, from chemical processes within water, and even from space. Analysis of this sedimentary material can tell us the recent history of an ocean basin, and sometimes the recent history of ...
Yin and yang of continental crust creation and destruction by plate
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
Zoned mantle convection
... inconsistent with the storage of old plates of ordinary oceanic lithosphere, i.e. with the concept of a plate graveyard. Isotopic inventories indicate that the deep-mantle composition is not correctly accounted for by continental debris, primitive material or subducted slabs containing normal oceani ...
... inconsistent with the storage of old plates of ordinary oceanic lithosphere, i.e. with the concept of a plate graveyard. Isotopic inventories indicate that the deep-mantle composition is not correctly accounted for by continental debris, primitive material or subducted slabs containing normal oceani ...
Geology, 39
... the main peak in crustal growth of the central NAC between 2.9 and 2.7 Ga (Nutman et al., 2004; Naeraa and Schersten, 2008). Furthermore, the eclogite age falls within the main mode of peridotite Re-Os model ages for NAC mantle lithosphere at 2.65 Ga (Wittig et al., 2010) (Fig. 1B). Despite the larg ...
... the main peak in crustal growth of the central NAC between 2.9 and 2.7 Ga (Nutman et al., 2004; Naeraa and Schersten, 2008). Furthermore, the eclogite age falls within the main mode of peridotite Re-Os model ages for NAC mantle lithosphere at 2.65 Ga (Wittig et al., 2010) (Fig. 1B). Despite the larg ...
Genesis of the Neogene to Quaternary volcanism in the Carpathian
... extension in the Pannonian Basin had a major role in the generation of the magmas. Dehydration of subducting slab should have resulted in thorough metasomatism in the mantle wedge during Cretaceous to early Miocene that would have lowered the melting temperature, therefore playing an indirect role i ...
... extension in the Pannonian Basin had a major role in the generation of the magmas. Dehydration of subducting slab should have resulted in thorough metasomatism in the mantle wedge during Cretaceous to early Miocene that would have lowered the melting temperature, therefore playing an indirect role i ...
Exhumation processes - Perso-sdt
... the severely extended Basin-and-Range province, appear to exhume only middle and upper crustal rocks, whereas continental collision zones expose rocks from 125 km and greater. Mantle rocks are locally exhumed in oceanic rifts and transform zones, probably due to the relatively thin crust associated ...
... the severely extended Basin-and-Range province, appear to exhume only middle and upper crustal rocks, whereas continental collision zones expose rocks from 125 km and greater. Mantle rocks are locally exhumed in oceanic rifts and transform zones, probably due to the relatively thin crust associated ...
Student_Worksheet_sediments
... attempt was made 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 an ...
... attempt was made 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 an ...
The discovery of a conjugate system of faults in the Wharton Basin
... to the 335°-striking normal faults that we observe in our study. Similarly, faults west of fracture zone F5 (fig. S5) have strikes between 330° and 340°, indicating that they might also have a similar origin. Although the basement highs and lows along the traces of F6 and F7 might represent the orig ...
... to the 335°-striking normal faults that we observe in our study. Similarly, faults west of fracture zone F5 (fig. S5) have strikes between 330° and 340°, indicating that they might also have a similar origin. Although the basement highs and lows along the traces of F6 and F7 might represent the orig ...
Could Iceland be a modern analogue for the Earth`s early
... differentiation and source composition. Martin and Sigmarsson (2007b) showed that in basalt flows, the composition (i.e. K2O ⁄ Na2O) of felsic melts in segregation veins is mainly controlled by the composition of the parental magma. In mantle plume environments, the basaltic precursors are already alk ...
... differentiation and source composition. Martin and Sigmarsson (2007b) showed that in basalt flows, the composition (i.e. K2O ⁄ Na2O) of felsic melts in segregation veins is mainly controlled by the composition of the parental magma. In mantle plume environments, the basaltic precursors are already alk ...
Asymmetry of high-velocity lower crust on the South
... or south of the Colorado transform fault, an area whose basement geology is buried by younger rocks. On the conjugate margin of South Africa, the coastal zone is underlain by the Neoproterozoic Kaoko, Damara and Gariep belts (from north to south, respectively). These are bordered on the east by olde ...
... or south of the Colorado transform fault, an area whose basement geology is buried by younger rocks. On the conjugate margin of South Africa, the coastal zone is underlain by the Neoproterozoic Kaoko, Damara and Gariep belts (from north to south, respectively). These are bordered on the east by olde ...
as a PDF
... Abstract: We present an updated synthesis of the widely accepted ‘single-arc Pacific-origin’ and ‘Yucatán-rotation’ models for Caribbean and Gulf of Mexico evolution, respectively. Fourteen palaeogeographic maps through time integrate new concepts and alterations to earlier models. Pre-Aptian maps ...
... Abstract: We present an updated synthesis of the widely accepted ‘single-arc Pacific-origin’ and ‘Yucatán-rotation’ models for Caribbean and Gulf of Mexico evolution, respectively. Fourteen palaeogeographic maps through time integrate new concepts and alterations to earlier models. Pre-Aptian maps ...
PDF (Chapter 3. The Crust and Upper Mantle)
... of the crust is based solely on seismological data. The Moho is a sharp seismological boundary and in some regions appears to be laminated. There are three major crustal types-continental, transitional and oceanic. Oceanic crust generally ranges from 5 to 15 km in thickness and comprises 60 percent ...
... of the crust is based solely on seismological data. The Moho is a sharp seismological boundary and in some regions appears to be laminated. There are three major crustal types-continental, transitional and oceanic. Oceanic crust generally ranges from 5 to 15 km in thickness and comprises 60 percent ...
Whole-mantle convection with tectonic plates preserves
... recycled9, 10, and the timing of incorporation into the convecting mantle11, 12. Suggested recycled components have included lower continental crust11, sub-continental lithospheric mantle10, 11, 13, altered ocean crust ± pelagic sediments6, and subduction modified mantle9, as well as material from l ...
... recycled9, 10, and the timing of incorporation into the convecting mantle11, 12. Suggested recycled components have included lower continental crust11, sub-continental lithospheric mantle10, 11, 13, altered ocean crust ± pelagic sediments6, and subduction modified mantle9, as well as material from l ...
Laboratory Title
... through the Cayman trough on south of the southeast coast of Cuba, and just north of Hispaniola, Puerto Rico, and the Virgin Islands. Part of the Puerto Rico Trench, the deepest part of the Atlantic Ocean (roughly 8,400 meters), lies along this border. The Puerto Rico trench is at a complex transit ...
... through the Cayman trough on south of the southeast coast of Cuba, and just north of Hispaniola, Puerto Rico, and the Virgin Islands. Part of the Puerto Rico Trench, the deepest part of the Atlantic Ocean (roughly 8,400 meters), lies along this border. The Puerto Rico trench is at a complex transit ...
accepted manuscript
... formation, whose plate boundary configuration remains uncertain. Paleomagnetic and magmatic studies suggest that the intra-oceanic arc was at equatorial latitudes during the Early Cretaceous before subduction resumed further north beneath the Eurasian margin (Lhasa terrane), with another hiatus in s ...
... formation, whose plate boundary configuration remains uncertain. Paleomagnetic and magmatic studies suggest that the intra-oceanic arc was at equatorial latitudes during the Early Cretaceous before subduction resumed further north beneath the Eurasian margin (Lhasa terrane), with another hiatus in s ...
Lecture 18
... through time to 2.5, the timeintegrated ratio should be somewhere in between these two v a l ues. Indeed, it is. However, the time-integrated value of 3.75 is surprisingly close to the initial value. This would imply in a simple evolutionary model of the mantle that the depletion in T h relative to ...
... through time to 2.5, the timeintegrated ratio should be somewhere in between these two v a l ues. Indeed, it is. However, the time-integrated value of 3.75 is surprisingly close to the initial value. This would imply in a simple evolutionary model of the mantle that the depletion in T h relative to ...
hydrogeology of the oceanic lithosphere
... oceanic crust were required to balance global geochemical budgets (Garrels and Mackenzie, 1971). These reactions include early diagenetic reactions that occur in the upper few meters of the sediment column (e.g., Sayles, 1979) as well as chemical exchange in basaltic basement (e.g., McDuff, 1981). I ...
... oceanic crust were required to balance global geochemical budgets (Garrels and Mackenzie, 1971). These reactions include early diagenetic reactions that occur in the upper few meters of the sediment column (e.g., Sayles, 1979) as well as chemical exchange in basaltic basement (e.g., McDuff, 1981). I ...
DEEP STRUCTURE AND GEOPHYSICAL PROCESSES BENEATH
... Julian for supplying computer programs which were subsequently modified; Drs. Jorge Mendiguren, Don Weidner and Professor Sean Solomon for helpful hints on reading seismograms; Dr. D. Joe Andrews for much advice on numerical and mathematical matters; Al Smith, Professors Richard Naylor, Seiya Uyeda ...
... Julian for supplying computer programs which were subsequently modified; Drs. Jorge Mendiguren, Don Weidner and Professor Sean Solomon for helpful hints on reading seismograms; Dr. D. Joe Andrews for much advice on numerical and mathematical matters; Al Smith, Professors Richard Naylor, Seiya Uyeda ...
accepted manuscript
... materials in enabling subduction processes, and the other concerning the capacity of the lithosphere to transport crustal rocks - future high-pressure metamorphic materials - to a great depth. As mentioned above, it is generally agreed, based both on models that oceanic subduction is possible due to ...
... materials in enabling subduction processes, and the other concerning the capacity of the lithosphere to transport crustal rocks - future high-pressure metamorphic materials - to a great depth. As mentioned above, it is generally agreed, based both on models that oceanic subduction is possible due to ...
Mantle convection models featuring plate tectonic behaviour
... Nearly 80 years ago, Arthur Holmes (1931) proposed that continents might move due to convective overturning in the Earth’s interior. Holmes correctly identified convection as the ultimate driving force for continental motion but his work did not define plates in the modern sense, rather it described m ...
... Nearly 80 years ago, Arthur Holmes (1931) proposed that continents might move due to convective overturning in the Earth’s interior. Holmes correctly identified convection as the ultimate driving force for continental motion but his work did not define plates in the modern sense, rather it described m ...
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.