C–O–H–S fluids and granitic magma : how S partitions and modifies CO2 concentrations of fluid-saturated felsic melt at 200 MPa

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Contributions to Mineralogy and Petrology 162 (2011): 849-865, doi:10.1007/s00410-011-0628-1.Hydrothermal volatile-solubility and partitioning experiments were conducted with fluid-saturated haplogranitic melt, H2O, CO2, and S in an internally heated pressure vessel at 900°C and 200 MPa; three additional experiments were conducted with iron-bearing melt. The run-product glasses were analyzed by electron microprobe, FTIR, and SIMS; and they contain ≤ 0.12 wt% S, ≤ 0.097 wt.% CO2, and ≤ 6.4 wt.% H2O. Apparent values of log ƒO2 for the experiments at run conditions were computed from the [(S6+)/(S6++S2-)] ratio of the glasses, and they range from NNO-0.4 to NNO+1.4. The C-O-H-S fluid compositions at run conditions were computed by mass balance, and they contained 22-99 mol% H2O, 0-78 mol% CO2, 0-12 mol% S, and < 3 wt% alkalis. Eight S-free experiments were conducted to determine the H2O and CO2 concentrations of melt and fluid compositions and to compare them with prior experimental results for C-O-H fluid-saturated rhyolite melt, and the agreement is excellent. Sulfur partitions very strongly in favor of fluid in all experiments, and the presence of S modifies the fluid compositions, and hence, the CO2 solubilities in coexisting felsic melt. The square of the mole fraction of H2O in melt increases in a linear fashion, from 0.05-0.25, with the H2O concentration of the fluid. The mole fraction of CO2 in melt increases linearly, from 0.0003-0.0045, with the CO2 concentration of C-O-H-S fluids. Interestingly, the CO2 concentration in melts, involving relatively reduced runs (log ƒO2 ≤ NNO+0.3) that contain 2.5-7 mol% S in the fluid, decreases significantly with increasing S in the system. This response to the changing fluid composition causes the H2O and CO2 solubility curve for C-O-H-S fluid-saturated haplogranitic melts at 200 MPa to shift to values near that modeled for C-O-H fluid-saturated, S-free rhyolite melt at 150 MPa. The concentration of S in haplogranitic melt increases in a linear fashion with increasing S in C-O-H-S fluids, but these data show significant dispersion that likely reflects the strong influence of ƒO2 on S speciation in melt and fluid. Importantly, the partitioning of S between fluid and melt does not vary with the (H2O/H2O+CO2) ratio of the fluid. The fluid-melt partition coefficients for H2O, CO2, and S and the atomic (C/S) ratios of the run-product fluids are virtually identical to thermodynamic constraints on volatile partitioning and the H, S, and C contents of pre-eruptive magmatic fluids and volcanic gases for subduction-related magmatic systems thus confirming our experiments are relevant to natural eruptive systems.This research was supported in part by National Science Foundation awards EAR 0308866 and EAR-0836741 to J.D.W

On the eliminating attempts toward Šesták–Berggren equation

Některé nedávné komentáře pochybují o originalitě Šestáka-Berggrenovy rovnice, přestože dosud téměř dosáhla Osm set citačních odpovědí. Hodnota rovnice SB je zkoumána z hlediska obecné logistické rovnice ukazující její Odlišná filozofická strategie od odlišného ortodoxního geometrického modelování v kinetice. Použití připojených výrazů "Zkrácený" a "rozšířený" je zpochybněn.Some recent commentaries doubt the originality of Šesták–Berggren equation even though it received until today almost eight hundred citation responses. The worth of SB equation is examined in terms of general logistic equation showing its divergent philosophical strategy from dissimilar orthodox geometrical modeling in kinetics. The use of appended terms ‘truncated’ and ‘extended’ is questioned

Šesták–Berggren equation: now questioned but formerly celebrated—what is right

Některé současné publikace zpochybňují originalitu Šestákovy-Berggrenovy (Š-B) rovnice, přestože je tato rovnice citována již v 785 případech. SB rovnice je důkladně analyzována a porovnána s jednotlivými geometrickými modely a jinými přístupy. Š-B rovnice je dále studována z hlediska obecné logistické rovnice, díky čemuž je zřejmá odlišná filozofická strategie mezi tradiční geometrickou JMAYK teorií a neslučitelnou kinetikou vyjádřenou dvou parametrickou SB rovnicí. Historie logistického modelování zahrnuje také využití ogivní sigmoidy. Široká aplikovatelnost této rovnice je doložena více než osmdesáti zdroji.Some recent papers doubt the originality of Sˇesta´k–Berggren equation even though it received until today as many as 785 citation responses. The SB equation is thus thoroughly analyzed and weighed against individual geometrical models and rivalry proposals. Moreover, the SB equation is examined in terms of general logistic equation showing divergent philosophical strategy between the traditional geometrical JMAYK versus the incommensurable kinetics through two parametric SB. The history of logistic modeling is revealed including ogive sigmoidal functions. The widespread application is noticed covering as many as eighty references

Light Sterile Neutrinos: A White Paper

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data

Light Sterile Neutrinos: A White Paper

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data