Magmatic anhydrite and calcite in the ore-forming quartz-monzodiorite magma at Santa Rita, New Mexico (USA): genetic constraints on porphyry-Cu mineralization

ISSN:0024-493

Estimation and testing of standard molar thermodynamic properties of tourmaline end-members using data of natural samples

Different estimation methods have been combined with calorimetric data for a natural Mg-rich tourmaline and dumortierite, a structurally similar borosilicate, to estimate thermodynamic properties of five tourmaline end-members (dravite, schorl, alkali-free dravite, aluminofoitite, and ferrifoitite). The results were tested by predicting the solubility of Fe-rich tourmaline in natural, low-variance hydrothermal mineral assemblages, for which the B concentration was independently known from Laser Ablation-ICP-MS analysis of coexisting fluid inclusions. Agreement within the uncertainty of experimental and thermodynamic data supports the validity of the estimation methods that used the fictive properties of the (B2O3)-B-III. Polyhedron for calculating standard enthalpy and entropy, and reactions involving dumortierite to estimate the heat-capacity functions. This study indicates more generally that the development of new microanalytical techniques for measuring the composition of natural fluid inclusions in well-constrained mineral assemblages represents a promising approach to estimating or testing thermodynamic data for complex silicates

Hautes doses d'immunoglobulines par voie intraveineuse pour le traitement des neutropénies "auto-immunes"

Two patients respectively with acute agranulocytosis and with chronic neutropenia were treated with high-dose immunoglobulins. In the first case, immunologic tests revealed the presence of antigranulocytic autoantibodies: all other tests (antinuclear antibodies, anti-DNA antibodies, immune complexes, latex) were negative. In the second case, all the above mentioned tests were negative. In both patients, neutrophil number returned to normal after the second immunoglobulin injection. Eight months after treatment, the neutrophil count was normal in the first patient and anti-granulocyte tests had become negative. In the second patient there was a late recurrence of neutropenia. The diagnosis of autoimmune neutropenia is difficult to confirm. In the case of peripheral "idiopathic" neutropenia, with infectious complications, high-dose immunoglobulin administration thus appears justified regardless of the results of the immunologic tests. This therapy also has the advantage of avoiding side effects of steroid treatment or of splenectomy

Characterisation of a Natural Quartz Crystal as a Reference Material for Microanalytical Determination of Ti, Al, Li, Fe, Mn, Ga and Ge

A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium in- quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 lg g-1),Al (154 ± 15 lg g-1), Li (30 ± 2 lg g-1), Fe (2.2 ± 0.3 lg g-1), Mn (0.34 ± 0.04 lg g-1), Ge (1.7 ± 0.2 lg g-1) and Ga (0.020 ± 0.002 lg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. oncentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz