نتایج جستجو برای: mantle

تعداد نتایج: 16918  

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2002
Francis Albarède Rob D Van Der Hilst

We review the present state of our understanding of mantle convection with respect to geochemical and geophysical evidence and we suggest a model for mantle convection and its evolution over the Earth's history that can reconcile this evidence. Whole-mantle convection, even with material segregated within the D" region just above the core-mantle boundary, is incompatible with the budget of argo...

2013
Hans-Peter Bunge

Mantle convection is vital to our Earth system. The relentless deformation produced inside the Earth's mantle by slow, viscous creep has a far greater impact on our planet than might be immediately evident. Continuously reshaping the Earth's surface, mantle convection provides the enormous driving forces necessary to support large-scale horizontal motion in the form of plate tectonics and the a...

2013
Claudio Faccenna Thorsten W. Becker Clinton P. Conrad Laurent Husson

[1] Mountain building at convergent margins requires tectonic forces that can overcome frictional resistance along large-scale thrust faults and support the gravitational potential energy stored within the thickened crust of the orogen. A general, dynamic model for this process is still lacking. Here we propose that mountain belts can be classified between two end-members. First, those of “slab...

1998
Louis Moresi Adrian Lenardic

The potential effects of continental crust on mantle convection are explored using threedimensional numerical simulations. The simulations model the coupling between a thin, deformable layer of chemically buoyant crust and a deep layer of thermally convecting and chemically dense mantle. Simulations begin with a crustal layer embedded within the upper thermal boundary layer of a mantle convecti...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2003
Jung-Fu Lin Dion L Heinz Ho-kwang Mao Russell J Hemley James M Devine Jie Li Guoyin Shen

Magnesiowüstite [(Mg,Fe)O] is the second most abundant mineral of Earth's lower mantle. Understanding its stability under lower mantle conditions is crucial for interpreting the physical and chemical properties of the whole Earth. Previous studies in an externally heated diamond anvil cell suggested that magnesiowüstites decompose into two components, Fe-rich and Mg-rich magnesiowüstites at 86 ...

2016
Jason P. Morgan Lars H. Rüpke William M. White

The Earth’s mantle convects to lose heat (Holmes, 1931); doing so drives plate tectonics (Turcotte and Oxburgh, 1967). Significant gravitational energy is created by the cooling of oceanic lithosphere atop hotter, less densemantle. When slabs subduct, this gravitational energy is mostly (∼86% for whole mantle flow in a PREM-like mantle) transformed into heat by viscous dissipation. Using this p...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Xiaoli Tang Jianjun Dong

Thermal conductivity of the Earth's lower mantle greatly impacts the mantle convection style and affects the heat conduction from the core to the mantle. Direct laboratory measurement of thermal conductivity of mantle minerals remains a technical challenge at the pressure-temperature (P-T) conditions relevant to the lower mantle, and previously estimated values are extrapolated from low P-T dat...

2010
Abigail A. Fraeman Jun Korenaga

We present a parameterized convection model of Mars by incorporating a new heat-flow scaling law for stagnant-lid convection, to better understand how the evolution of Mars may be affected by mantle melting. Melting in the mantle during convection leads to the formation of a compositionally buoyant lithosphere, which may also be intrinsically more viscous by dehydration. The consequences of the...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2002
Erik H Hauri

The decay of (187)Re to (187)Os (with a half-life of 42 billion years) provides a unique isotopic fingerprint for tracing the evolution of crustal materials and mantle residues in the convecting mantle. Ancient subcontinental mantle lithosphere has uniquely low Re/Os and (187)Os/(188)Os ratios due to large-degree melt extraction, recording ancient melt-depletion events as old as 3.2 billion yea...

2011
E. Martin I. Bindeman T. L. Grove

We report the oxygen isotope composition of olivine and orthopyroxene phenocrysts in lavas from the main magma types at Mt Shasta and Medicine Lake Volcanoes: primitive high-alumina olivine tholeiite (HAOT), basaltic andesites (BA), primitive magnesian andesites (PMA), and dacites. The most primitive HAOT (MgO [ 9 wt%) from Mt. Shasta has olivine dO (dOOl) values of 5.9–6.1%, which are about 1%...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید