Continents as a chemical boundary layer. MacGregor, I. Roberts Victor eclogites: ancient oceanic crust. Journal of Geophysical Research , 91 , — Morgan, P. The thermal structure and thermal evolution of the continental lithosphere. Physics and Chemistry of the Earth , 16 , — Pollack, H. Cratonization and thermal evolution of the mantle.
Earth and Planetary Science Letters , 80 , — Ritsema, J. New seismic model of the upper mantle beneath Africa. Geology Boulder , 28 1 , 63— Romanowicz, B. The thickness of tectonic plates. Science , , — Rudnick, R. Thermal structure, thickness and composition of continental lithosphere.
Chemical Geology , , — Rychert, C. A global view of the lithosphere-asthenosphere boundary. Scattered wave imaging of a sharp lithosphere-asthenosphere boundary beneath eastern North America. Sacks, I. The use of converted phases to infer the depth of the lithosphere-asthenosphere boundary beneath South America.
Journal of Geophysical Research , 82 , — Shapiro, S. Stability and dynamics of the continental tectosphere. This similarity, which is corroborated by seismic data, does not, however, mean that a chemical coupling exists between the subcontinental lithospheric mantle and continental crust in a similar way as for the oceanic lithosphere. Although magma generation and eruption through the continental lithosphere contribute to the growth of the continental crust and to the depletion of the subcontinental lithospheric mantle in incompatible elements, no simple chemical coupling should exist if the continental lithosphere were created by thermal accretion.
The petrology and geochemistry of the continental lithosphere can also be studied using xenoliths brought up to the surface by kimberlitic or alkalic volcanics. This technique attracted much attention because of the determination of pyroxene geotherms 9 and the claim that it permits the description of the palaeogeothermal structure of continents and oceans 10, Although some of the original conclusions seem premature 12 the basic idea is sound.
We have now used radiogenic tracers, the 87 Rb— 87 Sr system, to study the creation of the continental lithosphere. We present here results on garnet Iherzolite xenoliths from southern African kimberlites and discuss their geochemical and geodynamical implications. McDonald, G. Jordan, T. Nature , — Okal, E.
Oxburg, E. Bottinga, Y. Tectonophysics 18 , 1—17 Sclater, J. Kono, Y. Wells, P. Earth planet. Boyd, F. Carnegie Instn Washington 72 , — ; Phys. Earth 9 , — Google Scholar. MacGregor, I. CAS Google Scholar. Mercier, J-C. Wilshire, H. Shimizu, N. As the continental crust is lighter than the oceanic crust, the continental crust cannot subduct. We therefore still have some very old continental rocks at the surface of the Earth.
Skip to main content. Climate Sea Levels Why will sea level rise not be the same everywhere? How can we date corals? Geology and Tectonics Geology How do we know the age of the seafloor? Why is the seafloor so recent and the continental crust so old? Where do we find the oldest continental rocks and the oldest seafloor? What are the different types of rocks? What is a fossil and what are they used for? What are hydrothermal vents, and why do we find them along mid-ocean ridges?
Seismology What is a seismic wave? What is the difference between body waves and surface waves, and between P-waves and S-waves? Why can't S-waves travel through liquids? How far can seismic waves reach? Why do P-waves travel faster than S-waves? Why is the interior of the Earth hot?
What is the magnetic field of the Earth? Earthquakes and Faults Why do tectonic plates move? Brief history of the plate tectonics theory Before colliding with Asia, where was India?
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