μXANES study of iron redox state in serpentine during oceanic serpentinization

Andréani, M.; Muñoz, Manuel; Marcaillou, C.; Delacour, Adélie

doi:10.1016/j.lithos.2013.04.008

Cited by 142 publications

(101 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, the Fe‐poor serpentine‐brucite veins in magnetite‐rich harzburgite samples (DB11‐43 and DB11‐29) show comparatively higher X Mg of 0.94–0.97, suggesting serpentinization temperatures of 200–400°C [ Andreani et al ., ; Klein et al ., ]. Moreover, the Fe‐poor serpentine veins generally form in fluid‐dominated systems [ Beard et al ., ; Frost et al ., ], where the infiltration of oxidizing fluids drives the reactions of Fe‐rich serpentine and brucite to magnetite.…”

Section: Discussionmentioning

confidence: 99%

Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture‐zone magnetic anomalies

Zheng

Moskowitz

et al. 2017

JGR Solid Earth

View full text Add to dashboard Cite

Magnetic properties of a suite of variably serpentinized peridotites from the Dongbo ophiolite, SW Tibet (China), have been investigated to determine the magnetic signatures of suture zones. The degree of serpentinization (S) for these peridotites is mainly in the range of S < 60%. Petrography, mineral chemistry, and thermomagnetic analyses reveal that magnetite occurring in the interior of various serpentine veins is the predominant magnetic phase. Magnetic hysteresis and first‐order reversal curve diagrams suggest that the magnetite is mixture of interacting single‐domain, and pseudo‐single‐domain and/or multidomain particles. Superparamagnetic magnetite occurs in the S = 40–60% serpentinized but weakly magnetic dunites. Overall, the magnetite content and magnetic susceptibility increase consistently from ~0 to 20% of serpentinization and then decrease from S = 30 to 60%. Peak magnetite abundance is at S~25% (density, ~3.1 ± 0.05 g cm–3) and may suggest localized enrichment of fluids. The low magnetite abundance in dunite results from low‐temperature serpentinization. Finally, strong intensities of magnetization (1–10 Am–1) reside in the S > 60% and S = 20–30% serpentinized peridotites, indicating that peridotites with such degrees of serpentinization contribute to the aeromagnetic anomalies within the Yarlung‐Zangbo suture zone in south Tibet.

show abstract

Section: Discussionmentioning

confidence: 99%

Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture‐zone magnetic anomalies

Zheng

Moskowitz

et al. 2017

JGR Solid Earth

View full text Add to dashboard Cite

show abstract

“…However, these dissolution rates are for systems far from equilibrium and rates may decrease as the system approach equilibrium. In addition, serpentine minerals may contain both Fe(II) and Fe(III) and compositions ranging from nearly pure Fe(II) to nearly pure Fe(III) serpentine have been reported (Blauw et al 1979;Gonzàlez-Mancera et al 2003;Klein et al 2009;Andreani et al 2013). Based on the iron content, the Fe(II)/Fe(III) ratio and dissolution rate, it is likely that olivine and brucite contributed with more dissolved Fe(II) than serpentine.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Formation of H 2 , CH 4 and N-species during low-temperature experimental alteration of ultramafic rocks

et al. 2014

View full text Add to dashboard Cite

“…They are considered to be more oxidized than mid-ocean-ridge basalts12345 and are enriched in fluid-mobile and volatile elements6, a geochemical signature that reflects the interaction of mantle wedge peridotites with fluids released by the downgoing slab37. From the ridge to the trench, the oceanic lithosphere experiences hydration and oxidative alteration89 and ultimately delivers volatile element-rich oxidized material to the mantle wedge during subduction1011. It has therefore been proposed that slab-derived fluids released during prograde metamorphism can modify the redox state of the mantle wedge112.…”

mentioning

confidence: 99%

Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones

Pons¹,

Debret²,

Bouilhol³

et al. 2016

Nat Commun

View full text Add to dashboard Cite

Subduction zones modulate the chemical evolution of the Earth's mantle. Water and volatile elements in the slab are released as fluids into the mantle wedge and this process is widely considered to result in the oxidation of the sub-arc mantle. However, the chemical composition and speciation of these fluids, which is critical for the mobility of economically important elements, remain poorly constrained. Sulfur has the potential to act both as oxidizing agent and transport medium. Here we use zinc stable isotopes (δ66Zn) in subducted Alpine serpentinites to decipher the chemical properties of slab-derived fluids. We show that the progressive decrease in δ66Zn with metamorphic grade is correlated with a decrease in sulfur content. As existing theoretical work predicts that Zn-SO42− complexes preferentially incorporate heavy δ66Zn, our results provide strong evidence for the release of oxidized, sulfate-rich, slab serpentinite-derived fluids to the mantle wedge.

show abstract

μXANES study of iron redox state in serpentine during oceanic serpentinization

Cited by 142 publications

References 48 publications

Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture‐zone magnetic anomalies

Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for suture‐zone magnetic anomalies

Formation of H 2 , CH 4 and N-species during low-temperature experimental alteration of ultramafic rocks

Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones

Contact Info

Product

Resources

About