Mechanisms for folding of high-grade rocks in extensional tectonic
... This review of structures developed in extensional high-grade terrains, combined with results of centrifuge analogue modelling, illustrates the range of fold styles and mechanisms for folding of amphibolite to granulite facies rocks during rifting or the collapse of a thrust-thickened orogen. Severa ...
... This review of structures developed in extensional high-grade terrains, combined with results of centrifuge analogue modelling, illustrates the range of fold styles and mechanisms for folding of amphibolite to granulite facies rocks during rifting or the collapse of a thrust-thickened orogen. Severa ...
Seamounts – characteristics, formation, mineral deposits and
... seamounts suggests that the Josephine Bank (north Atlantic) was perhaps the first identified seamount and in 1938, the term “seamount” was first officially given by the US Board of Geographic Names to the Davidson Seamount (Brewin et al., 2007). Until 1964, about 2000 seamounts had been discovered, ...
... seamounts suggests that the Josephine Bank (north Atlantic) was perhaps the first identified seamount and in 1938, the term “seamount” was first officially given by the US Board of Geographic Names to the Davidson Seamount (Brewin et al., 2007). Until 1964, about 2000 seamounts had been discovered, ...
Practice mdtrm
... b. He could not provide a mechanism for the movement of the continents. c. He could provide only illogical explanations for the movement of the continents. d. His evidence was incorrect. What kind of plate boundary occurs where two plates grind past each other without destroying or producing lithosp ...
... b. He could not provide a mechanism for the movement of the continents. c. He could provide only illogical explanations for the movement of the continents. d. His evidence was incorrect. What kind of plate boundary occurs where two plates grind past each other without destroying or producing lithosp ...
The lunar moho and the internal structure of the Moon
... on the origin of the solar system or even the Moon until comparatively recently, given the complexity in having to assimilate a vast amount of data from differing fields. In pre-Apollo times it was commonly believed that the Moon compared to Earth is geologically an inactive planet and exactly for th ...
... on the origin of the solar system or even the Moon until comparatively recently, given the complexity in having to assimilate a vast amount of data from differing fields. In pre-Apollo times it was commonly believed that the Moon compared to Earth is geologically an inactive planet and exactly for th ...
On the tectonic origin of Iberian topography - E
... and the Central System) shows a mean elevation close to one thousand meters above sea level in average, some hundreds of meters higher than the southern half of the Iberian plate. This elevated area corresponds to (i) the top of sedimentation in Tertiary terrestrial endorheic sedimentary basins (Pal ...
... and the Central System) shows a mean elevation close to one thousand meters above sea level in average, some hundreds of meters higher than the southern half of the Iberian plate. This elevated area corresponds to (i) the top of sedimentation in Tertiary terrestrial endorheic sedimentary basins (Pal ...
Radiogenic isotopes - Department of Geological Sciences
... temporal changes in Earth surface processes. This paper briefly reviews the principles of radiogenic isotope geochemistry and the distribution of a number of elements of interest in the environment, and then uses this information to explore the range of applications to chemical stratigraphy and othe ...
... temporal changes in Earth surface processes. This paper briefly reviews the principles of radiogenic isotope geochemistry and the distribution of a number of elements of interest in the environment, and then uses this information to explore the range of applications to chemical stratigraphy and othe ...
Evolution of the Paleo-Asian Ocean (Altai−Sayan Region, Central
... phengite ages are 540±24 and 576±11 Ma (schists from serpentinitic melange). The K−Ar amphibole age of the garnet amphibolite (Chagan−Uzun massif) is 535± −24 Ma and Ar−Ar amphibole ages from the eclogitic part are 636± 10 Ma and 627± Ma. The K−Ar amphibole age of island-arc ophiolites is 523±23 Ma. ...
... phengite ages are 540±24 and 576±11 Ma (schists from serpentinitic melange). The K−Ar amphibole age of the garnet amphibolite (Chagan−Uzun massif) is 535± −24 Ma and Ar−Ar amphibole ages from the eclogitic part are 636± 10 Ma and 627± Ma. The K−Ar amphibole age of island-arc ophiolites is 523±23 Ma. ...
Trace Element and Isotope Geochemistry of the Volcanic Rocks of
... is characterized by much wider ranges of radiogenic isotopes ,87Sr/86Sr Q-7048-0-7077, 143Nd/144Nd 0-5128-0-5123 and INTRODUCTION ho6pb/2O4pb 19.7-20-2), in which all of the Sr and Pb ratios The island of Bequia lies in the southern section of are higher and Nd ratios are lower than those of the IHS ...
... is characterized by much wider ranges of radiogenic isotopes ,87Sr/86Sr Q-7048-0-7077, 143Nd/144Nd 0-5128-0-5123 and INTRODUCTION ho6pb/2O4pb 19.7-20-2), in which all of the Sr and Pb ratios The island of Bequia lies in the southern section of are higher and Nd ratios are lower than those of the IHS ...
Crystal Fractionation processes at Baru Volcano from the Deep to
... likely thicker than the crust in the Panama Canal region, estimated at ~25 km [BricenoGuarupe, 1978]. In other sections of the Central American Arc, Oligocene and Miocene arc sequences lie behind the currently active arc front (i.e. Costa Rican arc) [Carr et al., 2003; Gazel et al., 2009]. At Baru v ...
... likely thicker than the crust in the Panama Canal region, estimated at ~25 km [BricenoGuarupe, 1978]. In other sections of the Central American Arc, Oligocene and Miocene arc sequences lie behind the currently active arc front (i.e. Costa Rican arc) [Carr et al., 2003; Gazel et al., 2009]. At Baru v ...
Seismic Anisotropy of Subduction Zone Minerals–Contribution of
... phlogopite (4.8 wt% H2O), 10Å phase (10–13 wt% H2O), clinohumite (2.8 wt% H2O) in hydrated peridotites, lawsonite (11.5 wt% H2O) and zoisite (2.0 wt% H2O) in hydrated metamorphosed basalts and potassium rich phengite (4.6 wt%H2O) in metamorphosed sediments. 3. High pressure (>7 GPa) minerals such as ...
... phlogopite (4.8 wt% H2O), 10Å phase (10–13 wt% H2O), clinohumite (2.8 wt% H2O) in hydrated peridotites, lawsonite (11.5 wt% H2O) and zoisite (2.0 wt% H2O) in hydrated metamorphosed basalts and potassium rich phengite (4.6 wt%H2O) in metamorphosed sediments. 3. High pressure (>7 GPa) minerals such as ...
Baltica upside down: A new plate tectonic model for Rodinia and the
... The Wilson Cycle (Wilson, 1966), i.e., the orthogonal opening and closing of an early Paleozoic Atlantic-type ocean (the Iapetus Ocean; Harland and Gayer, 1972) revolutionized plate tectonic thinking and has represented one of the mainstays of pre-Mesozoic plate reconstructions. Current models intim ...
... The Wilson Cycle (Wilson, 1966), i.e., the orthogonal opening and closing of an early Paleozoic Atlantic-type ocean (the Iapetus Ocean; Harland and Gayer, 1972) revolutionized plate tectonic thinking and has represented one of the mainstays of pre-Mesozoic plate reconstructions. Current models intim ...
Resolving the lithosphereasthenosphere boundary with seismic
... within the lithosphere and asthenosphere. It is still a matter of debate, however, how accurately and under what conditions surface waves can resolve the depth and thickness of the lithosphere–asthenosphere boundary (LAB). We investigate the sensitivity of Rayleigh waves to LAB properties and find t ...
... within the lithosphere and asthenosphere. It is still a matter of debate, however, how accurately and under what conditions surface waves can resolve the depth and thickness of the lithosphere–asthenosphere boundary (LAB). We investigate the sensitivity of Rayleigh waves to LAB properties and find t ...
A. M. Celâl ŞENGÖR, Boris A. NATAL`IN, Gürsel
... We have been able to find no evidence anywhere in the Altaids for independent trans-oceanic migrations of numerous 'terranes' tied to individual subduction zones. Only two major subduction zones were responsible for the entire Altaid evolution from the beginning to the end and this is consistent not ...
... We have been able to find no evidence anywhere in the Altaids for independent trans-oceanic migrations of numerous 'terranes' tied to individual subduction zones. Only two major subduction zones were responsible for the entire Altaid evolution from the beginning to the end and this is consistent not ...
Kohlstedt answers PDF
... Question 1: I have always wanted to ask this question of someone who studies the mid ocean ridge. I understand that the mid-ocean ridge is a pull apart zone, that is being pulled apart by the mantle convection? Right? Ok, but when I think of the mantle pushing to the surface at the ridge I envision ...
... Question 1: I have always wanted to ask this question of someone who studies the mid ocean ridge. I understand that the mid-ocean ridge is a pull apart zone, that is being pulled apart by the mantle convection? Right? Ok, but when I think of the mantle pushing to the surface at the ridge I envision ...
Outer slope faulting associated with the western Kuril and Japan
... heights increase from the crest of the trench outer swell down to a depth of about 6000 m on the slope of the outer trench wall, but with no distinct increase below that depth. No significant difference is recognized in fault throws towards and away from the trench. It can be concluded that these el ...
... heights increase from the crest of the trench outer swell down to a depth of about 6000 m on the slope of the outer trench wall, but with no distinct increase below that depth. No significant difference is recognized in fault throws towards and away from the trench. It can be concluded that these el ...
Earth & Space Science An open source text edited by MPS teachers
... is claimed to be infringing or to be the subject of infringing activity. You must include sufficient information, such as a specific page number or other specific identification, for us to locate the material. 3. Information for us to be able to contact the claimant (e.g., email address, phone numbe ...
... is claimed to be infringing or to be the subject of infringing activity. You must include sufficient information, such as a specific page number or other specific identification, for us to locate the material. 3. Information for us to be able to contact the claimant (e.g., email address, phone numbe ...
IODP Proposal Cover Sheet
... The IODP Science Plan states that; ‘The creation and growth of continental crust remains one of the fundamental, unsolved problems in Earth science.’ The formation and evolution of the continental crust is a first order problem of terrestrial geochemistry because for many trace and minor elements, t ...
... The IODP Science Plan states that; ‘The creation and growth of continental crust remains one of the fundamental, unsolved problems in Earth science.’ The formation and evolution of the continental crust is a first order problem of terrestrial geochemistry because for many trace and minor elements, t ...
The track of the Yellowstone hot spot
... their divergent-convergent inflection point; and (6) a geoid dome that centers on Yellowstone and has a diameter and height similar to those of oceanic hot spots. We conclude that the neotectonic fault belts and the Yellowstone crescent of high terrain reflect heating that is associated with the hot ...
... their divergent-convergent inflection point; and (6) a geoid dome that centers on Yellowstone and has a diameter and height similar to those of oceanic hot spots. We conclude that the neotectonic fault belts and the Yellowstone crescent of high terrain reflect heating that is associated with the hot ...
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.