نتایج جستجو برای: earth mantle

تعداد نتایج: 108664  

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2008
Thomas S Duffy

Understanding planetary structure and evolution requires a detailed knowledge of the properties of geological materials under the conditions of deep planetary interiors. Experiments under the extreme pressure-temperature conditions of the deep mantle are challenging, and many fundamental properties remain poorly constrained or are inferred only through uncertain extrapolations from lower pressu...

2006
Michael J. Spicuzza Lawrence A. Taylor John W. Valley

We report new high-precision laser fluorination three-isotope oxygen data for lunar materials. Terrestrial silicates with a range of δO values (−0.5 to 22.9‰) were analyzed to independently determine the slope of the terrestrial fractionation line (TFL; λ=0.5259±0.0008; 95% confidence level). This new TFL determination allows direct comparison of lunar oxygen isotope systematics with those of E...

2010
Renata M. Wentzcovitch Yonggang G. Yu Zhongqing Wu

This research has been motivated by geophysics and materials physics. The objective of this research has been to advance materials theory and computations for high pressure and high temperature applications to the point that it can make a difference in our understanding of the Earth. Understanding of the mineralogy, composition, and thermal structure of the Earth evolves by close interaction of...

Journal: :Nature chemistry 2013
Qiang Zhu Daniel Y Jung Artem R Oganov Colin W Glass Carlo Gatti Andriy O Lyakhov

Xenon, which is quite inert under ambient conditions, may become reactive under pressure. The possibility of the formation of stable xenon oxides and silicates in the interior of the Earth could explain the atmospheric missing xenon paradox. Using an ab initio evolutionary algorithm, we predict the existence of thermodynamically stable Xe-O compounds at high pressures (XeO, XeO(2) and XeO(3) be...

2016
Tatsuya Sakamaki Akio Suzuki Bjorn Mysen

Preface A special session entitled “Early Earth from accumulation to formation-” was held on May 24, 2015 during the Japan Geoscience Union (JpGU) annual meeting. This session aimed to bring together high-pressure/hightemperature experiment on physics and chemistry of deep Earth materials, natural observation, and theoretical modeling within the principal subject areas of “Early Earth” research...

2014
Zhongqing Wu Fang Huang Shichun Huang

a Laboratory of Seismology and Physics of Earth’s Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China b Mengcheng National Geophysical Observatory, Anhui, China c CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026,...

2005
S. M. Wang M. Damon David A. Yuen

It is widely acknowledged that an important aspect in Earth Science research is the ability to visualize huge amounts of data resulting from numerical simulations or data acquisition. Whether the data is a simple two-dimensional plot or a three-dimensional multivariate grid, the ability to visualize the data is imperative for researchers to properly demonstrate results. This poster will examine...

2007
GERALD SCHUBERT DAVID STEVENSON PATRICK CASSEN

It is widely believed that the surface heat ftows of the earth and moon provide good measures of the total amounts of radioactives in these bodies. Simple thermal evolution models, based on subsolidus whole mantle convection, indicate that this may not be the case. These models have been constructed assuming an initially h~t st~te, but with a wide varlet~ of choices for the parameters character...

2007
C. O'Neill A. Lenardic L. Moresi T. H. Torsvik

The Precambrian geological record shows peak of activity at 1.1, 1.9–2.1, 2.7 and 3.5 Ga, often associated with massive crustal production, orogenesis and supercontinent cycles. It has been suggested that these bursts of tectonic activity are due to mantle avalanche events, where accumulating subducted slabs periodically penetrate the 670 km discontinuity, and subsequent upwelling counterflow a...

Journal: :Science 2005
T M Harrison J Blichert-Toft W Müller F Albarede P Holden S J Mojzsis

The long-favored paradigm for the development of continental crust is one of progressive growth beginning at approximately 4 billion years ago (Ga). To test this hypothesis, we measured initial 176Hf/177Hf values of 4.01- to 4.37-Ga detrital zircons from Jack Hills, Western Australia. epsilonHf (deviations of 176Hf/177Hf from bulk Earth in parts per 10(4)) values show large positive and negativ...

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