Chapter 4. TTG & Genesis of the Continental Crust
... TTG is an acronym for “tonalite-trondhjemite-granodiorite”. These granitoids, together with greenstone belts, are a typical feature of all Archean terrains. In addition, a rarer feature of Archean terrains is the occurrence of high-Mg diorite-tonalite-granodiorite rocks, collectively called “sanuki ...
... TTG is an acronym for “tonalite-trondhjemite-granodiorite”. These granitoids, together with greenstone belts, are a typical feature of all Archean terrains. In addition, a rarer feature of Archean terrains is the occurrence of high-Mg diorite-tonalite-granodiorite rocks, collectively called “sanuki ...
Dynamics of continental collision: influence of the plate contact
... nature, there is ample evidence that continental crust may have experienced pressure of about 30–35 kbar. The evidence comes from ultra-high pressure metamorphic minerals (e.g. coesite, diamond) revealing subduction of continental crust to mantle depth and subsequent exhumation (e.g. Smith 1984; Lio ...
... nature, there is ample evidence that continental crust may have experienced pressure of about 30–35 kbar. The evidence comes from ultra-high pressure metamorphic minerals (e.g. coesite, diamond) revealing subduction of continental crust to mantle depth and subsequent exhumation (e.g. Smith 1984; Lio ...
as a PDF
... 5.8 Ma and are from NUVEL-1A (DeMets et al., 1994). When continental regions with active deformation are excluded, satellite geodetic measurements, available for the last ∼ 25 years, typically yield similar Euler vectors (e.g. Sella et al., 2002). However, any such geologic and geodetic data can onl ...
... 5.8 Ma and are from NUVEL-1A (DeMets et al., 1994). When continental regions with active deformation are excluded, satellite geodetic measurements, available for the last ∼ 25 years, typically yield similar Euler vectors (e.g. Sella et al., 2002). However, any such geologic and geodetic data can onl ...
Himalaya - Southern-Tibet: the typical continent
... After collision, India did not stop; it moved northward by over 1900 ± 850 km with respect to Asia at an average speed of 50 mm/year. jpb – Continent-Continent Collision in the Himalayas ...
... After collision, India did not stop; it moved northward by over 1900 ± 850 km with respect to Asia at an average speed of 50 mm/year. jpb – Continent-Continent Collision in the Himalayas ...
Hoffman2013_Cordille.. - Department of Earth Sciences
... Rise (Pitman and Heirtzler 1966). The Eltanin-19 profile remains the longest, cleanest and most symmetrical of any spreading ridge in the world (Atwater 2001), convincing even LamontDoherty’s Director Maurice Ewing and other skeptics that sea-floor spreading was a reality (Glen 1982; Le Pichon 1986) ...
... Rise (Pitman and Heirtzler 1966). The Eltanin-19 profile remains the longest, cleanest and most symmetrical of any spreading ridge in the world (Atwater 2001), convincing even LamontDoherty’s Director Maurice Ewing and other skeptics that sea-floor spreading was a reality (Glen 1982; Le Pichon 1986) ...
Lecture 18
... There were, and are, good arguments why the depleted reservoir should overlie the primitive one. First, it is generally thought the depleted reservoir acquires its characteristics through loss of a partial melt to form the crust. Obviously this reservoir should then be nearer the continental crust. ...
... There were, and are, good arguments why the depleted reservoir should overlie the primitive one. First, it is generally thought the depleted reservoir acquires its characteristics through loss of a partial melt to form the crust. Obviously this reservoir should then be nearer the continental crust. ...
Composition of the martian crust
... spectra from crater units will then be compared with lab-collected thermal emission spectra and globally representative TES spectra, such as Sytis-type and Acidalia-type surfaces, to make a preliminary qualitative classification. Next, lab-collected spectra from infrared spectral libraries will be u ...
... spectra from crater units will then be compared with lab-collected thermal emission spectra and globally representative TES spectra, such as Sytis-type and Acidalia-type surfaces, to make a preliminary qualitative classification. Next, lab-collected spectra from infrared spectral libraries will be u ...
Episodic Tremor and Slip
... Episodic Tremor and Slip often caused by traffic or wind. The timing of the seismic signal, the tremor, coincided with the timing of the slip. The key proof that it is indeed generated by a tectonic source is that the signals correlated at several stations over distances of up to 100 km (60 miles), ...
... Episodic Tremor and Slip often caused by traffic or wind. The timing of the seismic signal, the tremor, coincided with the timing of the slip. The key proof that it is indeed generated by a tectonic source is that the signals correlated at several stations over distances of up to 100 km (60 miles), ...
The structure and dynamics of the mantle wedge
... use of unexplained jargon I will provide a short discussion of various terms that I will use, starting with the main causes and consequences of deformation in subduction zones. Subduction zones occur at the boundaries where tectonic plates converge. The main driving force of this motion is buoyancy, ...
... use of unexplained jargon I will provide a short discussion of various terms that I will use, starting with the main causes and consequences of deformation in subduction zones. Subduction zones occur at the boundaries where tectonic plates converge. The main driving force of this motion is buoyancy, ...
Science Highlights of the RCL Initiative
... 3. Role of Rift Obliquity Important factors: (a) Oblique extension and strikeslip faults; (b)Relationship between the orientation of the rift and relative motion direction (° of obliquity); (c) Rift obliquity affects resulting morphology of the rift zone (Gulf of CA vs. Red Sea). 4. Role of Magmatis ...
... 3. Role of Rift Obliquity Important factors: (a) Oblique extension and strikeslip faults; (b)Relationship between the orientation of the rift and relative motion direction (° of obliquity); (c) Rift obliquity affects resulting morphology of the rift zone (Gulf of CA vs. Red Sea). 4. Role of Magmatis ...
New Tectonic Map of Georgia (Explanatory Note)
... submarine volcanites and microcontinental (of passive margin type in the Mesozoic with the shallow marine sediments, and of the Andean type active ...
... submarine volcanites and microcontinental (of passive margin type in the Mesozoic with the shallow marine sediments, and of the Andean type active ...
The subjective scale of intensity used most often to show areas of
... C) No. Faults in earthquakes never move up and down. D) No. Faults in earthquakes sometimes are preceded by ground uplift, but not always E) No. Faults that rise up are usually associated with volcanoes and not earthquakes Answer: D Section: 3.9 Bloom's Taxonomy: Application 3. What are the main typ ...
... C) No. Faults in earthquakes never move up and down. D) No. Faults in earthquakes sometimes are preceded by ground uplift, but not always E) No. Faults that rise up are usually associated with volcanoes and not earthquakes Answer: D Section: 3.9 Bloom's Taxonomy: Application 3. What are the main typ ...
Effect of wedge geometry and structural heterogeneity on
... Effect of wedge geometry and structural heterogeneity on subduction erosion processes: insights from 2D sandbox analogue experiments Albert, F.1, Kukowski, N.1 (1) Department 3 Geodynamik, GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany [email protected] At convergent margin ...
... Effect of wedge geometry and structural heterogeneity on subduction erosion processes: insights from 2D sandbox analogue experiments Albert, F.1, Kukowski, N.1 (1) Department 3 Geodynamik, GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany [email protected] At convergent margin ...
Buckling instabilities of subducted lithosphere beneath the transition
... The apparent thickening of the slab in the tomographic images – equivalent to about five times the slab thickness – is too large to be easily explained by a mechanism other than buckling. The principal alternative, sometimes called ‘advective’ or ‘pure shear’ thickening, is uniform widening of the s ...
... The apparent thickening of the slab in the tomographic images – equivalent to about five times the slab thickness – is too large to be easily explained by a mechanism other than buckling. The principal alternative, sometimes called ‘advective’ or ‘pure shear’ thickening, is uniform widening of the s ...
When did India–Asia collide and make the Himalaya?
... have been recorded in southern Tibet and elsewhere indicating a ~ 55 Ma collision of an island arc system with India (Event 1) and a younger Oligocene age of the India–Asia continental collision (Event 2) 29. Two-stage Cenozoic collision is also postulated from estimating amount of convergence: 50 M ...
... have been recorded in southern Tibet and elsewhere indicating a ~ 55 Ma collision of an island arc system with India (Event 1) and a younger Oligocene age of the India–Asia continental collision (Event 2) 29. Two-stage Cenozoic collision is also postulated from estimating amount of convergence: 50 M ...
formations of continents and mountains
... • Identify how fossils provide evidence about how life and the environment have changed on the earth over time. These Unit Goals comply directly with the National Science Education Standards for grades 5-9 in Earth and Space Science: Formations of Continents and Mountains • The solid earth is layere ...
... • Identify how fossils provide evidence about how life and the environment have changed on the earth over time. These Unit Goals comply directly with the National Science Education Standards for grades 5-9 in Earth and Space Science: Formations of Continents and Mountains • The solid earth is layere ...
Thermal and mechanical structure of the central Iberian Peninsula
... of 80 and 50 mW m2 showed deviations from mean elevation data greater than F500 m and were consequently not considered for thermal and rheological purposes. For example, a surface heat flow of 80 mW m2 was determined at an oil well in the Tajo Basin near the Central System boundary. In this partic ...
... of 80 and 50 mW m2 showed deviations from mean elevation data greater than F500 m and were consequently not considered for thermal and rheological purposes. For example, a surface heat flow of 80 mW m2 was determined at an oil well in the Tajo Basin near the Central System boundary. In this partic ...
Discharge of Tectonic Stresses in the Earth Crust by High
... increased level of seismic activity was observed within 3 to 6 days after the MHD generator firing runs. It was suggested that electromagnetic pulses result in discharge of energy accumulated by the Earth crust due to tectonic deformation processes. The energy discharges in the form of series of rel ...
... increased level of seismic activity was observed within 3 to 6 days after the MHD generator firing runs. It was suggested that electromagnetic pulses result in discharge of energy accumulated by the Earth crust due to tectonic deformation processes. The energy discharges in the form of series of rel ...
The lithosphere: rocks and minerals
... Rocks are materials that make up the Earth’s crust and mantle. Rocks are a mix of one or various solid substances called minerals. In nature, there are many different types of rocks. They can be distinguished by looking at three characteristics. • Composition. This is the mix of minerals that make ...
... Rocks are materials that make up the Earth’s crust and mantle. Rocks are a mix of one or various solid substances called minerals. In nature, there are many different types of rocks. They can be distinguished by looking at three characteristics. • Composition. This is the mix of minerals that make ...
Origins of the plume hypothesis and some of its
... same beneath hotspots and normal ridges. The validity of these assumptions and alternatives are potentially detectable from petrological studies. Edge-driven convection could conceivably recirculate the material beneath the ridge axis leading to much more melting than implied by the model (e.g., Kin ...
... same beneath hotspots and normal ridges. The validity of these assumptions and alternatives are potentially detectable from petrological studies. Edge-driven convection could conceivably recirculate the material beneath the ridge axis leading to much more melting than implied by the model (e.g., Kin ...
Escape tectonics and the extrusion of Alaska: Past, present, and future
... the mobility of the present-day margin. Western British Columbia and southern Alaska constitute a diffuse plate boundary zone characterized by non-rigid deformation, mountain building, and block rotations (e.g., Stein and Freymueller, 2002). Here, we suggest that the “Bering Block” of Mackey et al., ...
... the mobility of the present-day margin. Western British Columbia and southern Alaska constitute a diffuse plate boundary zone characterized by non-rigid deformation, mountain building, and block rotations (e.g., Stein and Freymueller, 2002). Here, we suggest that the “Bering Block” of Mackey et al., ...
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.