Earth differentiation

Weyer S, Anbar AD, Brey GP, Miinker C, Mezger K (2005) Iron isotope fractionation during planetary differentiation. Earth Planet Sci Lett 240 251-264 White JWC (1989) Stable hydrogen isotope ratios in plants a review of current theory and some potential applications. In Stable isotopes in ecological research. Ecological Studies 68. Springer Verlag, New York, p. 142-162... 

Walker D. and Agee C. (1989) Partitioning equilibrium, temperature gradients, and constraints on Earth differentiation. Earth Planet. Sci. Lett. 96, 49-60. 

Carlson R. W. and Hauri E. (2003) Mantle-crust mass balance and the extent of Earth differentiation. Earth Planet. Set Utt. (submitted 2002). 

Staudigel H. and King S. D. (1992) Ultrafast subduction the key to slab recycling efficiency and mantle differentiation Earth Planet. Sci. Lett. 109, 517—530. 

A study of the radiogenic isotope memory of the Earth s mantle clearly shows that the mantle is neither an independent part of the Earth system nor has it been for a long time. But rather, it records a history of the extraction and recycling of both basaltic and continental crust. This raises two very important questions. First, is our isotopic record of the mantle representative of the whole mantle or only the upper mantle Second, is there any primitive, undifferentiated mantle still preserved within the large mass of the differentiated Earth s mantle ... 

Boyet, M., Blichert-Toft, J., Rosing, M., Storey, M., Telouk, P., and Albarede, F., 2003. 142Nd evidence for early earth differentiation. Earth Planet. Sci. Lett., 214, 427-42. 

Weyer, S., Anbar, A.D., Brey, G.P., Miinker, C., Mezger, K., and Woodland, A.B. (2005) Iron isotope fractionation dining planetary differentiation. Earth Planet. Sci. Lett., 240, 251-264. 

The addition of this stage of filtering will bring the very high-frequeney attenuation under eontrol and further attenuate any differential-mode noise on the earth ground lead. It will also produee a eombined attenuation of -36 dB at the switehing frequency of the power supply. 

According to this assignment the differentiating electron, that is, the final electron to enter the atom of lutetium, wss seen as an f electron. This suggested that lutetium should be the final element in the first row of the rare earth elements, in which f electrons are progressively filled, and not a transition element as had been believed by the chemists. As a result of more recent spectroscopic experiments the configuration of ytterbium has been altered to (27)... 

The origin of atmospheric turbulence is diurnal heating of the Earth s surface, which gives rise to the convection currents that ultimately drive weather. Differential velocities caused perhaps when the wind encounters an obstacle such as a mountain, result in turbulent flow. The strength of the turbulence depends on a number of factors, including geography it is noted that the best observation sites tend to be the most windward mountaintops of a range— downwind sites experience more severe turbulence caused by the disturbance of those mountains upwind. 

Many years ago, geochemists recognized that whereas some metallic elements are found as sulfides in the Earth s crust, others are usually encountered as oxides, chlorides, or carbonates. Copper, lead, and mercury are most often found as sulfide ores Na and K are found as their chloride salts Mg and Ca exist as carbonates and Al, Ti, and Fe are all found as oxides. Today chemists understand the causes of this differentiation among metal compounds. The underlying principle is how tightly an atom binds its valence electrons. The strength with which an atom holds its valence electrons also determines the ability of that atom to act as a Lewis base, so we can use the Lewis acid-base model to describe many affinities that exist among elements. This notion not only explains the natural distribution of minerals, but also can be used to predict patterns of chemical reactivity. 

Such phenomena do not occur in heavier alkaline earth atoms due to a poorer differential overlap between the valence s and p orbitals (smaller Ksp integrals) as explained by... 

Rabinowicz M, Ceuleneer G, Monnereau M, Rosemberg C (1990) Three-dimensional models of mantle flow across a low-viscosity zone implications for hotspot dynamics. Earth Planet Sci Lett 99 170-184 Reid MR(1995) Processes of mantle enrichment and magmatic differentiation in the eastern Snake River Plain Th isotope evidence. Earth Planet Sci Lett, 131 239-254 Reid MR, Ramos FC (1996) Chemical dynamics of enriched mantle in the southwestern United States Thorium isotope evidence. Earth Planet Sci Lett, 138 67-81. 

Sigmarsson O, Condomines M, Fomcade S (1992) A detailed Th, Sr and O isotope study of Hekla differentiation processes in an Icelandic Volcano. Contrib Mineral Petrol 112 20-34 Sigmarsson O, Condomines M, Fourcade S (1992) Mantle and crustal contribution in the genesis of recent basalts from off-rift zones in Iceland constraints from Th, Sr and O isotopes. Earth Planet Sci Lett 110 149-162... 

Albarede F (2001) Radiogenic ingrowth in systems with multiple reservoirs applications to the differentiation of the mantle-crust system. Earth Planet Sci Lett 189 59-73... 

Reagan MK, Sims KW, Erich J, Thomas RB, Cheng H, Edwards RL, Layne G, Ball L (2003) Timescales of differentiation from mafic parents to rhyolite in North American continental arcs. J Petrol (in press) Regelous M, Collerson KD, Ewart A, Wendt JI (1997) Trace element transport rates in subduction zones evidence from Th, Sr and Pb isotope data for Tonga-Kermadec arc lavas. Earth Planet Sci Lett 150 291-302... 

The quantity dyl3 In a2 at the potential of the electrocapillary maximum is of basic importance. As the surface charge of the electrode is here equal to zero, the electrostatic effect of the electrode on the ions ceases. Thus, if no specific ion adsorption occurs, this differential quotient is equal to zero and no surface excess of ions is formed at the electrode. This is especially true for ions of the alkali metals and alkaline earths and, of the anions, fluoride at low concentrations and hydroxide. Sulphate, nitrate and perchlorate ions are very weakly surface active. The remaining ions decrease the surface tension at the maximum on the electrocapillary curve to a greater or lesser degree. 

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