Total mercury in the air and rain water has been measured in order to study the residence time of mercury in the atmosphere. The mercury concentration in air directly affected by terrestrial sources varies by a factor of 7 whereas in ocean air it shows a constant value, 1 ng/m³ throughout the seasons. On the other hand, mercury in rain water shows also a constant value, 1 ng/l for any rainfall and for any phase of it. These observations suggest that mercury in the atmosphere behaves as a vapour, and the rate of its elimination from the atmosphere is slow. From both data, the residence time of mercury in the atmosphere is estimated to be 5.7 years.

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Rare-earth elements and Ba abundances for several fragments of the Allende meteorite were determined. Even for a powder sample carefully prepared, REE and Ba abundances determined were found to vary occasionally from portion to portion taken; a portion happened to demonstrate a very high Ba content and a considerably fractionated REE pattern as comapred with the “representative” ones. This fact suggests the possible presence of Ba-rich micro-component with fractionated REE pattern in the Allende meteorite. Observations from other bulk samples of the same meteorite also corroborate this inference.

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The interconnection between the dissipation of radiogenic ⁴He and ⁴⁰Ar from the Earth's crust and mantle and the Earth's thermal evolution is considered. A model coupling the ⁴He and ⁴⁰Ar dissipation from the mantle with the zone melting in the upper mantle is proposed. The input functions in analytic form for ⁴He and ⁴⁰Ar flows into the atmosphere are followed by the solution of the Earth's thermal evolution. The solutions are given for cases describing multiple mantle melting under continents and, perhaps, single melting under the oceans. These solutions are in good agreement with the ⁴⁰Ar economy in the atmosphere and the flow of modern ⁴He into the atmosphere. Probably about 60% of the modern ⁴⁰Ar abundance dissipated to the atmosphere during the first melting cycle.

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The isotopic composition of the enigmatic xenon component (the so-called Renazzo-type fission xenon, CCF or X), which is said to be released from carbonaceous chondrites at temperatures 600 to 1, 000°C, is explained in terms of the variation of the isotopic ratios due to a combined effect of massfractionation, neutron capture and cosmic-ray irradiation processes, which took place during the early history of the solar system.

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The calculation of non-ideality in a multicomponent solution phase is studied by considering various solution models. The use of an empirical multicomponent solution model is indicated when bulk thermodynamic properties are available for binary solutions. KOHLER has developed an empirical excess free energy model which places no restrictions on the form of binary non-idealities yet it is efficient and is very easily expressed as G^X(K) = ∑^n-1_i=1∑ⁿ_j>i(N_i + N_j)² G^X_ij where G^X_ij is the value of G^X in the binary ij at a normalized composition of N_i/(N_i + N_j). Only binary interactions are considered in this model and because many silicates (solids, liquids) show strong changes in association/dissociation phenomena as additional components are added, KOHLER's model will not be sufficient by itself. It needs to be combined with an empirical multicomponent correction free energy model which takes into consideration a few experimental points. Correction free energy models are meant to describe interactions that involve more than two components and so they should not have the flaw of extending into any binary. Existing ternary correction models have this flaw which can be removed by introducing an exponent. Two so-modified multicomponent correction free energy models are proposed here and the first has n coefficients and is expressed as n G^k = [∑^n-1_i=1∑ⁿ_j>i (1-N_i-N_j)]^γ [∑_i=1 N_iK_i], where γ is the introduced exponent (γ > 1) and K_i are the correction coefficients. This correction, which is based on only n-component experimental data, acts on all subsystems with more than two components. A second correction model has been designed to overcome this subsystem action. This second model accumulates m correction coefficients for every possible 3 ≤ m ≤ n component interaction leading to a total of n2^n-1-n² coefficients. The coefficients of an m-component interaction do not affect the calculations in any m-1 component or smaller subsystem. The model is based on the logic leading to KOHLER's model and is expressed as G^k = ∑_m∑_I(NI)^γm G^k_φ(I) where G^k_φ(I) is the value of G^k in the m-ternary system with components φ(I) at a normalized composition while NI is the sum of N_i in φ(I). KOHLER's model and these two empirical correction models are easily computerized, both in terms G and U_i so that they can be easily incorporated into any computer program that presently assumes ideal mixing of the solution phases.

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The spinodal surface and the stable binodal surface must touch tangentially at any extremum/saddle point and along any consolute line. Because of this, the most convenient way to study immiscibility in a ternary is to calculate the spinodal surface. Other authors have accomplished this in a binary regular and subregular solution and in a ternary regular solution but the derived equations are not applicable to a ternary subregular solution or to a Kohler solution. The equation for the spinodal in a ternary Kohler solution is herein derived so that now it is possible to study immiscibility using the spinodal in any ternary Kohler solution, including a subregular ternary solution. MEIJIRING used the spinodal equation to derive relations which characterise the form of segregation in a ternary regular solution. When the “effective” regular solution parameter is substituted into these relations, they can be used as a rough approximation to characterise segregation in a subregular ternary solution; the number of peaks and saddles in the ternary solvus can be predicted but the temperature/composition of them cannot. This rough scheme is used with a graph which shows that the composition of the critical point on a subregular binary solvus is only a function of the ratio of the two subregular parameters. The temperature dependence of subregular solution parameters is capable of exerting a strong control on the unique features of a ternary spinodal, so that a more exact study of immiscibility must involve the calculation of the spinodal surface using temperature dependent solution parameters. A model spinodal for the ternary feldspar system at l kb is calculated using temperature dependent subregular solution parameters.

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The chemical analyses of the mineral waters issuing in the basin of Vichy St Yorre provide the means to decipher different subsuperficial modifications superposed on the fluid originating at great depths: (1) Increasing amounts of dissolved Ca, Sr, Mg and sometimes K, by gradual attack of shallow host rocks. (2) Precipitation of silica and associated aluminium. (3) Mixing with fresh surface waters. The comprehensive study of these alterations allows to shed light on the initial composition of deep water. From the silica content, the Na/K ratio and the calcite saturation, a temperature of 135°C is inferred for this water.

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