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A thermodynamic model for sulfur content at sulfide saturation (scss) in hydrous silicate melts: With implications for arc magma genesis and sulfur recycling

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GEOCHIMICA ET COSMOCHIMICA ACTA 2022年 325卷 187-204页

作者： Li, Huijuan Zhang, Lifei Peking Univ Sch Earth & Space Sci MOE Key Lab Orogen Belts & Crustal Evolut 5 Yiheyuan Rd Beijing 100871 Peoples R China

Modeling the effect of H2O on the "sulfur content at sulfide saturation" (scss) in silicate melt is essential for the estimation of scss in both arc magmas and slab melts. Here we present a thermodynamic approach, in which, scss in hydrous silicate melt has been modeled as a combination of S dissolving as S2- and HS-/H2S, based on the sulfide capacity (CS2-) and the hydro-sulfide capacity (C-HS), respectively. By adopting the thermodynamic framework of O'Neill and Mavrogenes (2002), S dissolution as HS- /H2S can be modeled in an analogous fashion to that for modeling S2- in anhydrous melt with the relation: ln [HS](scss) = -Delta G degrees (Fes-FeO)/RT + lnC(HS) - lna(FeO)(melt) + lna(FeS)(sulfide). To obtain an expression for C-HS, we compiled published experimental data on scss in hydrous silicate melts covering a PT range of 0.15-3 GPa and 785-1600 degrees C, and melt H2O contents of similar to 1-13 wt%. While the contribution of S dissolving as S2- in basaltic and andesitic melts can be calculated based on the updated scss model for anhydrous basic melt from O'Neill (2021), S2- is considered negligible in rhyolitic and dacitic melts, i.e., when melt FeO content scss values is +/- 50% for hydrous rhyolitic and dacitic melts, and +/- 10-30% for hydrous basaltic and andesitic melts, representing a significant improvement in comparison to previous models. Our model produces scss values for the primitive arc magmas compiled by Ruscitto et al. (2012), that are in most cases higher than the measured S contents, implying sulfide

关键词： scss Hydro-sulfide capacity H2S dissolution Hydrous silicate melt Arc magma S recycling

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半导体色敏传感器(scss)原理及其检测电路

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华北矿业高等专科学校学报 2000年第1期2卷 19-22页

作者：王久和华北矿业高等专科学校电子与信息工程系北京东燕郊101601

系统的介绍了半导体色敏传感器(scss)的测色原理,建立了光照下P-N结短路电流与波长的关系。给出了scss单色及三颜色检测电路,为工程设计奠定了基础。

关键词：色敏传感器波长光电流放大器电路检测 scss

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Redox Melting of Garnet Lherzolite: Generation of Carbonated Silicate and Sulfide Melts and Implications for OIB Formation From Chalcophile and Redox-Sensitive Elements

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GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 2025年第3期26卷

作者： Fux, Michael Schmidt, Max W. Liebske, Christian ETH Dept Earth & Planetary Sci Zurich Switzerland

Upwellings in the Earth's mantle become sufficiently oxidizing for CO2-induced redox melting at depths equivalent to similar to 8-5 GPa, generating deep incipient mantle melts. This study simulates the geochemistry of the redox melting process by conducting multi-anvil experiments at 5 GPa and slightly superadiabatic 1,450 degrees C. By stepwise increasing the oxygen content in a graphite- and sulfide-saturated bulk silicate Earth (BSE)-like composition, sulfide and carbonated silicate melts were produced and coexist with garnet +/- olivine +/- orthopyroxene +/- clinopyroxene. Carbonated silicate melts contain 31-38 wt.% SiO2, 9-17 wt.% CO2, 270-475 ppm S and have an X(Mg )of 0.75-0.77;the sulfide melts have molar metal/(S + O) and Ni/(Fe + Ni) ratios of 1.08-1.23 and 0.59-0.69, respectively. The experiments were doped with chalcophile and/or redox-sensitive trace elements to derive mineral/carbonated silicate melt/sulfide melt partition coefficients. Sulfide melt/carbonated silicate melt partition coefficients are lithophile for Ga, P, V, Mn, Ge, Cr, Zn and In increasing in this sequence from 0.005 to 0.9, and chalcophile for Cd, Mo, Sn, Tl, Pb, Co, Sb, As, Ni, Bi, Se and Te, increasing from 3 to similar to 6000. We use our data to model trace element concentrations in incipient redox melts and apply our results to ocean island basalt (OIB) genesis. Our redox melting model suggests that average concentrations of most trace elements in primitive and Si-undersaturated OIBs can be well explained by 1%-2% melting of sulfide-saturated depleted mantle mixed with 10-20 wt.% of recycled oceanic crust that includes minor sediment when retaining some sulfide melt in the source.

关键词： redox melting carbonated silicate melt partition coefficient chalcophile element OIB scss

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The fate of sulfide during decompression melting of peridotite implications for sulfur inventory of the MORB-source depleted upper mantle

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EARTH AND PLANETARY SCIENCE LETTERS 2017年 459卷 183-195页

作者： Ding, Shuo Dasgupta, Rajdeep Rice Univ Dept Earth Sci 6100 Main StMS 126 Houston TX 77005 USA

Magmatism at mid ocean ridges is one of the main pathways of S outflux from deep Earth to the surface reservoirs and is a critical step in the global sulfur cycle, yet our understanding of the behavior of sulfide during decompression melting of the upper mantle is incomplete. In order to constrain the sulfur budget of the mantle and reconcile the sulfur and chalcophile element budget of mantle partial melts parental to primitive mid-ocean ridge basalts (MORBs), here we developed a model to describe the behavior of sulfide and Cu during decompression melting by combining the pMELTS thermodynamic model and empirical sulfur contents at sulfide concentration (scss) models, taking into account the effect of the presence of Ni and Cu in sulfides on scss of mantle-derived melts. Calculation of scss along melting adiabat at mantle potential temperature of 1380 degrees C with variable initial S content in the mantle indicates that the complete consumption or partial survival of sulfide in the melting residue depends on initial S content and degree of melting. Primitive MORBs (Mg# > 60) with S and Cu mostly concentrated in 800-1000 ppm and 80-120 ppm are likely mixture of sulfide undersaturated high degree melts and sulfide saturated low degree melts derived from depleted peridotite containing 100-200 ppm S. Model calculations to capture the effects of variable mantle potential temperatures (1280-1420 degrees C) indicate that for a given abundance of sulfide in the mantle, hotter mantle consumes sulfide more efficiently than colder mantle owing to the effect of temperature in enhancing sulfide solubility in silicate melt, and higher mantle temperature stabilizing partial melt with higher FeO* and lower SiO2 and Al2O3, all of which generally enhance sulfide solubility. However, sulfide can still be exhausted by similar to 10-15% melting with bulk S of 100-150 ppm in the mantle when T-p is as low as 1300 degrees C. We also show that although variation of D-Cu(peridotite/melt) a

关键词： deep sulfur MORB decompression melting scss

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Multiple-beamline operation of SACLA

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JOURNAL OF SYNCHROTRON RADIATION 2019年第PT 2期26卷 595-602页

作者： Tono, Kensuke Hara, Toru Yabashi, Makina Tanaka, Hitoshi Japan Synchrotron Radiat Res Inst JASRI XFEL Utilizat Div 1-1-1 Kouto Sayo Hyogo 6795198 Japan RIKEN SPring 8 Ctr 1-1-1 Kouto Sayo Hyogo 6795148 Japan

The SPring-8 angstrom ngstrom Compact free-electron LAser (SACLA) began parallel operation of three beamlines (BL1-3) in autumn 2017 to increase the user beam time of the X-ray free-electron laser. The success of the multiple-beamline operation is based on two technological achievements: (i) the fast switching operation of the SACLA main linear accelerator, which provides BL2 and BL3 with pulse-by-pulse electron beams, and (ii) the relocation and upgrade of the SPring-8 Compact SASE Source for BL1, for the generation of a soft X-ray free-electron laser. Moreover, the photon beamlines and experimental stations were upgraded to facilitate concurrent user experiments at the three beamlines and accommodate more advanced experiments.

关键词： X-ray free-electron laser SACLA multiple-beamline operation scss photon beamline

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Sulfide and sulfate saturation of dacitic melts as a function of oxygen fugacity

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GEOCHIMICA ET COSMOCHIMICA ACTA 2022年 326卷 1-16页

作者： Kleinsasser, Jackie M. Simon, Adam C. Konecke, Brian A. Kleinsasser, Michael J. Beckmann, Philipp Holtz, Francois Univ Michigan Dept Earth & Environm Sci Ann Arbor MI USA NASA JSC Astromat Res & Explorat Sci ARES Houston TX USA Fathom Geophys LLC Heath OH USA Univ Michigan Sch Publ Hlth Dept Biostat Ann Arbor MI USA Leibniz Univ Hannover Inst Mineral Hannover Germany

Sulfur is a key element in terrestrial magmatic processes yet its geochemical behavior remains one of the most difficult to model due to its heterovalent chemistry. The maximum amount of sulfur a silicate melt can dissolve before saturating with sulfide (e.g., pyrrhotite) or sulfate (e.g., anhydrite) changes with the redox state of the system and has important implications for the sulfur budget of a magmatic system. Several empirical models have been developed to predict the sulfur content of a silicate melt at either sulfide (under reducing conditions) or sulfate (under oxidizing conditions) saturation, but only one model existed that systematically assessed how the sulfur content of a basaltic melt changes as a function of oxygen fugacity (fO(2)) across the transition from sulfide- to sulfate-dominated conditions. The applicability of that model to intermediate and felsic melts rests on the assumption that changes in melt composition do not affect how sulfide or sulfate dissolves in the melt. Here, we report new experimental data that constrain the sulfur concentration at sulfide saturation (scss) and the sulfur concentration at anhydrite saturation (SCAS) in a dacitic melt as a function of fO(2). The experiments were conducted using a H2O-saturated natural dacitic melt at 1000 degrees C, 300 MPa, and at log fO(2) varying over four orders of magnitude encompassing the sulfide-sulfate transition (log fO(2) = Delta FMQ-0.7, Delta FMQ+0, Delta FMQ+0.5, Delta FMQ+1, Delta FMQ+1.48, Delta FMQ+1.54, Delta FMQ +1.75, Delta FMQ+2.08 and Delta FMQ+3.3). New scss and SCAS data and modeling for dacitic melts reveals that the sulfide-sulfate transition occurs at Delta FMQ+1.81 +/- 0.56, defined by the following equations to predict the sulfur content of intermediate to evolved silicate melts as a function of fO(2): scssdacitic = [S2-] (1 + 10((2.00 Delta FMQ - 3.05))) SCAS(dacitic) = [S6+] (1 + e((1.26 - 2.00 Delta FMQ))) The results presented here demonstrate that the basalt

关键词： scss SCAS Sulfide saturation Sulfate saturation Dacitic melts

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Evidence for a sulfur-undersaturated lunar interior from the solubility of sulfur in lunar melts and sulfide-silicate partitioning of siderophile elements

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GEOCHIMICA ET COSMOCHIMICA ACTA 2018年 231卷 130-156页

作者： Steenstra, E. S. Seegers, A. X. Eising, J. Tomassen, B. G. J. Webers, F. P. F. Berndt, J. Klemme, S. Matveev, S. van Westrenen, W. Vrije Univ Fac Sci Amsterdam Netherlands Carnegie Inst Sci Geophys Lab 5251 Broad Branch Rd NW Washington DC 20015 USA Univ Munster Inst Mineral Munster Germany Univ Utrecht Fac Geosci Utrecht Netherlands

Sulfur concentrations at sulfide saturation (scss) were determined for a range of low-to high-Ti lunar melt compositions (synthetic equivalents of Apollo 14 black and yellow glass, Apollo 15 green glass, Apollo 17 orange glass and a late-stage lunar magma ocean melt, containing between 0.2 and 25 wt.% TiO2) as a function of pressure (1-2.5 GPa) and temperature (1683-1883 K). For the same experiments, sulfide-silicate partition coefficients were derived for elements V, Cr, Mn, Co, Cu, Zn, Ga, Ge, As, Se, Mo, Sn, Sb, Te, W and Pb. The scss is a strong function of silicate melt composition, most notably FeO content. An increase in temperature increases the scss and an increase in pressure decreases the scss, both in agreement with previous work on terrestrial, lunar and martian compositions. Previously reported scss values for high-FeO melts were combined with the experimental data reported here to obtain a new predictive equation to calculate the scss for high-FeO lunar melt compositions. Calculated scss values, combined with previously estimated S contents of lunar low-Ti basalts and primitive pyroclastic glasses, suggest their source regions were not sulfide saturated. Even when correcting for the currently inferred maximum extent of S degassing during or after eruption, sample S abundances are still > 700 ppm lower than the calculated scss values for these compositions. To achieve sulfide saturation in the source regions of low-Ti basalts and lunar pyroclastic glasses, the extent of degassing of S in lunar magma would have to be orders of magnitude higher than currently thought, inconsistent with S isotopic and core-to-rim S diffusion profile data. The only lunar samples that could have experienced sulfide saturation are some of the more evolved A17 high-Ti basalts, if sulfides are Ni- and/or Cu rich. Sulfide saturation in the source regions of lunarmelts is also inconsistent with the sulfide-silicate partitioning systematics of Ni, Co and Cu. Segregation of signif

关键词： Moon Volatiles Siderophile Chalcophile Sulfides scss

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High sulfur solubility in subducted sediment melt under both reduced and oxidized conditions: With implications for S recycling in subduction zone settings

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GEOCHIMICA ET COSMOCHIMICA ACTA 2021年 304卷 305-326页

作者： Li, Huijuan Zhang, Lifei Bao, Xinjian Wykes, Jeremy L. Liu, Xi Peking Univ Sch Earth & Space Sci MOE Key Lab Orogen Belts & Crustal Evolut 5 Yiheyuan Rd Beijing 100871 Peoples R China Australian Synchrotron 800 Blackburn Rd Clayton Vic 3168 Australia

The relative enrichment of sulfur (S) observed in arc magmas when compared to MORB, reflects the addition of slab-derived S to the mantle wedge source region. However, the mechanisms and efficiency of such S recycling remain poorly constrained. In this study, sediment melting experiments have been conducted using a synthetic pelite starting composition containing similar to 7 wt% H2O and similar to 1.9 wt% S, at 3 GPa, 1050 degrees C and variable oxygen fugacity (fO(2)), to investigate the effect of fO(2) on S solubility in sediment melts. To assess temperature and concentration effects, selected experiments were repeated either at lower temperatures of 950 degrees C and 1000 degrees C, or with a higher bulk S content of similar to 4 wt%. All experiments produced hydrous rhyolitic melts, saturated with either pyrrhotite under reduced conditions or anhydrite under oxidized conditions. For 3 GPa, 1050 degrees C experiments, the sulfur content at sulfide saturation (scss) in melt is found to increase with decreasing fO(2), from similar to 200 ppm at FMQ-0.5 to similar to 1900 ppm at FMQ-7.5. The highest S solubility is achieved at FMQ + 1.6 where melt is saturated with both anhydrite and pyrrhotite. The sulfur content at sulfate saturation (SCAS) decreases from similar to 2600 ppm at FMQ + 1.6 to similar to 2000 ppm at FMQ + 7. Increasing either bulk S content or temperature produces a positive effect on scss and SCAS. Raman spectra of our experimental melts show that S exists as H2S/HS- under reduced conditions and as SO42- under oxidized conditions. The solubility minimum, i.e., the onset of transition from S2- to S6+ is estimated to occur at similar to FMQ, with full transition to S6+ by similar to FMQ + 2. While the SCAS values are in good agreement with previous reports, the distinct increase of scss with decreasing fO(2) (when fO(2) < FMQ) has not been observed in previous slab melting experiments. Furthermore, we report for the first time that dissolution of H2S

关键词： scss SCAS Sediment melt Oxygen fugacity Fincham-Richardson relationship Sulfur recycling

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Predicting sulfide precipitation in magma oceans on Earth, Mars and the Moon using machine learning

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GEOCHIMICA ET COSMOCHIMICA ACTA 2024年 366卷 237-249页

作者： Zhangzhou, J. Li, Yuan Chowdhury, Proteek Sen, Sayan Ghosh, Urmi Xu, Zheng Liu, Jingao Wang, Zaicong Day, James M. D. Zhejiang Univ Sch Earth Sci Key Lab Geosci Big Data & Deep Resource Zhejiang P Hangzhou Peoples R China Chinese Acad Sci Guangzhou Inst Geochem State Key Lab Isotope Geochem Guangzhou 510640 Peoples R China Rice Univ Dept Earth Environm & Planetary Sci Houston TX 77005 USA Bengurion Univ Negev Zuckerberg Inst Water Res IL-8499000 Ben Gurion Israel James Hutton Inst Environm & Biochem Sci Craigiebuckler Aberdeen AB15 8QH Scotland Indian Inst Technol IIT Kharagpur Dept Geol & Geophys Kharagpur 721302 India China Univ Geosci Beijing State Key Lab Geol Proc & Mineral Resources Beijing Peoples R China China Univ Geosci Sch Earth Sci State Key Lab Geol Proc & Mineral Resources Wuhan 430074 Peoples R China Univ Calif San Diego Scripps Inst Oceanog La Jolla CA 92093 USA

The sulfur content at sulfide saturation (scss) of a silicate melt can regulate the stability of sulfides and, therefore, chalcophile elements' behaviors in planetary magma oceans. Many studies have reported high-pressure experiments to determine scss using either linear or exponential regressions to parameterize the thermodynamics of the system. Although these empirical equations describe the effects of different parameters on scss, they perform poorly when predicting laboratory measurements. Here, we compiled 542 published analyses of experiments performed on a range of sulfide and silicate compositions at varying P-T conditions (<24 GPa, <2673 K). Using empirical equations, linear regression, Random Forest algorithms, and a hybrid algorithm employing empirical fits to P-T conditions and the Random Forest algorithm for compositions, we developed several scss models and compared them to laboratory measurements. The Random Forest and hybrid models (R-2 = 0.82-0.91, mean average error [MAE] < 746 ppmw S, residual mean standard error [RMSE] < 972 ppmw S), significantly outperform previous empirical models (R-2 = 0.28-0.69, MAE = 622-1,170 ppmw S, RMSE = 1,070-1,744 ppmw S), whereas linear regression performs moderately well, i.e., between the classic and machine learning models. We applied our hybrid model to predict scss during magma ocean solidification on Earth, Mars, and the Moon, and we compared our model results to expected S contents in the residual magma oceans calculated by mass balance. Our results confirm that during early accretion, sulfides precipitated from magma oceans and into the outer cores of Earth and Mars, but not the Moon. Subsequently, once the respective magma oceans began precipitating minerals with increasingly FeO-rich and SiO2-, Al2O3-, and MgO-depleted compositions, the increasing S concentration in the residual magma was offset by temperature and compositional effects on scss, preventing sulfide precipitation during intermediate stages of

关键词： scss Machine learning Sulfide Magma ocean

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An unsupervised approach for co-channel speech separation using Hilbert-Huang transform and Fuzzy C-Means clustering

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INTERNATIONAL JOURNAL OF SPEECH TECHNOLOGY 2017年第1期20卷 1-13页

作者： Kumar, M. K. Prasanna Kumaraswamy, R. BMS Coll Engn Bangalore 560019 Karnataka India Siddaganga Inst Technol Tumkur 572103 Karnataka India

In this paper we discuss an unsupervised approach for co-channel speech separation where two speakers are speaking simultaneously over same channel. We propose a two stage separation process where the initial stage is based on empirical mode decomposition (EMD) and Hilbert transform generally known as Hilbert-Huang transform. EMD decomposes the mixed signal into oscillatory functions known as intrinsic mode functions. Hilbert transform is applied to find the instantaneous amplitudes and Fuzzy C-Means clustering is applied to group the speakers at initial stage. In second stage of separation speaker groups are transformed into time-frequency domain using short time Fourier transform (STFT). Time-frequency ratio's are computed by dividing the STFT matrix of mixed speech signal and STFT matrix of stage1 recovered speech signals. Histogram of the ratios obtained can be used to estimate the ideal binary mask for each speaker. These masks are applied to the speech mixture and the underlying speakers are estimated. Masks are estimated from the speech mixture and helps in imputing the missing values after stage1 grouping of speakers. Results obtained show significant improvement in objective measures over other existing single-channel speech separation methods.

关键词： BSS scss Fuzzy C-Means EMD IMF TFR IBM HHT

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