Formation of Zn- and Fe-sulfides near hydrothermal vents at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs

التفاصيل البيبلوغرافية
العنوان: Formation of Zn- and Fe-sulfides near hydrothermal vents at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs
المؤلفون: Heileen Hsu-Kim, Jeffrey J. Tsang, George W. Luther, Mustafa Yücel, Katherine M. Mullaugh
المصدر: Geochemical Transactions
Geochemical Transactions, Vol 9, Iss 1, p 6 (2008)
بيانات النشر: Springer Nature
مصطلحات موضوعية: 010504 meteorology & atmospheric sciences, Sulfide, media_common.quotation_subject, Mineralogy, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Hydrothermal circulation, lcsh:Chemistry, Mackinawite, Geochemistry and Petrology, 14. Life underwater, lcsh:Environmental sciences, 0105 earth and related environmental sciences, media_common, lcsh:GE1-350, chemistry.chemical_classification, Speciation, Sphalerite, lcsh:QD1-999, chemistry, 13. Climate action, Environmental chemistry, engineering, Seawater, Pyrite, Geology, Research Article, Hydrothermal vent
الوصف: Background The speciation of dissolved sulfide in the water immediately surrounding deep-ocean hydrothermal vents is critical to chemoautotrophic organisms that are the primary producers of these ecosystems. The objective of this research was to identify the role of Zn and Fe for controlling the speciation of sulfide in the hydrothermal vent fields at the Eastern Lau Spreading Center (ELSC) in the southern Pacific Ocean. Compared to other well-studied hydrothermal systems in the Pacific, the ELSC is notable for unique ridge characteristics and gradients over short distances along the north-south ridge axis. Results In June 2005, diffuse-flow (< 50°C) and high-temperature (> 250°C) vent fluids were collected from four field sites along the ELSC ridge axis. Total and filtered Zn and Fe concentrations were quantified in the vent fluid samples using voltammetric and spectrometric analyses. The results indicated north-to-south variability in vent fluid composition. In the high temperature vent fluids, the ratio of total Fe to total Zn varied from 39 at Kilo Moana, the most northern site, to less than 7 at the other three sites. The concentrations of total Zn, Fe, and acid-volatile sulfide indicated that oversaturation and precipitation of sphalerite (ZnS(s)) and pyrite (FeS2(s)) were possible during cooling of the vent fluids as they mixed with the surrounding seawater. In contrast, most samples were undersaturated with respect to mackinawite (FeS(s)). The reactivity of Zn(II) in the filtered samples was tested by adding Cu(II) to the samples to induce metal-exchange reactions. In a portion of the samples, the concentration of labile Zn2+ increased after the addition of Cu(II), indicating the presence of strongly-bound Zn(II) species such as ZnS clusters and nanoparticles. Conclusion Results of this study suggest that Zn is important to sulfide speciation at ELSC vent habitats, particularly at the southern sites where Zn concentrations increase relative to Fe. As the hydrothermal fluids mix with the ambient seawater, Zn-sulfide clusters and nanoparticles are likely preventing sulfide oxidation by O2 and reducing bioavailability of S(-II) to organisms.
اللغة: English
تدمد: 1467-4866
DOI: 10.1186/1467-4866-9-6
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::265898b9f19d2845e1cca7f22dac262a
Rights: OPEN
رقم الانضمام: edsair.doi.dedup.....265898b9f19d2845e1cca7f22dac262a
قاعدة البيانات: OpenAIRE
الوصف
تدمد:14674866
DOI:10.1186/1467-4866-9-6