Fluid inclusions in Ebelyakh diamonds: Evidence of CO2 liberation in eclogite and the effect of H2O on diamond habit

Smith, Evan M.; Kopylova, Maya G.; Frezzotti, Maria Luce; Afanasiev, V. P.

doi:10.1016/j.lithos.2014.12.010

Cited by 44 publications

(27 citation statements)

References 82 publications

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“…These diamonds have similar morphological features to the dark grey rounded diamonds which are widespread in the alluvial placers of the northeastern part of the Siberian platform [3][4][5][6][7]. They are classified as variety V with aggregates of variety VII, according to the Yu.…”

Section: Introductionmentioning

confidence: 76%

Specific Internal Structure of Diamonds from Zarnitsa Kimberlite Pipe

et al. 2017

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Abstract:The Zarnitsa kimberlite pipe is one of the largest pipes of the Yakutian diamondiferous province. Currently, some limited published data exists on the diamonds from this deposit. Among the diamond population of this pipe there is a specific series of dark gray to black diamonds with transition morphologies between octahedron and rounded rhombic dodecahedron. These diamonds have specific zonal and sectorial mosaic-block internal structures. The inner parts of these crystals have polycrystalline structure with significant misorientations between sub-individuals. The high consistency of the mechanical admixtures (inclusions) in the diamonds cores can cause a high grid stress of the crystal structure and promote the block (polycrystalline) structure of the core components. These diamond crystals have subsequently been formed due to crystallization of bigger sub-individuals on the polycrystalline cores according to the geometric selection law.

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Section: Introductionmentioning

confidence: 76%

Specific Internal Structure of Diamonds from Zarnitsa Kimberlite Pipe

et al. 2017

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“…They are presumably products of Raman cross‐sections and instrumental efficiencies as relative cross‐section for CO 2 obtained from Bergman & Dubessy () is close to the product of instrumental efficiency coefficient ( z = 0.51) and effective cross‐section coefficient

{normalξ}_{{CO}_{2}}^{*} = 2.5

(ξ = z , ξ* = 1.275) used in the work of Smith et al . (). Mole fractions of CO in CO–CO 2 mixture (where molar fraction of CO 2 was 0.154, 0.164, and 0.062) were calculated in accordance with formula reported in the study of Bergman & Dubessy ():

X_{i} = \frac{A_{i} / {normalξ}_{i}}{\sum_{i} A_{i} false/ ξ_{i}}

…”

Section: Resultsmentioning

confidence: 97%

“…Quantitative estimates require determination of Raman cross-sections (ξ) and instrumental efficiencies for all components: CO, N 2 , CO 2 (Smith et al 2015). We used the 'relative cross-sections' of Raman scattering (n CO ¼ 0:95 and n O2 ¼ 1:25) from Bergman & Dubessy (1984).…”

Section: Fluid In Albite Glassmentioning

confidence: 99%

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DryCO₂–COfluid as an important potential deep Earth solvent

et al. 2016

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Transport properties of reduced carbonic fluid have been studied experimentally at P = 2 kbar and T = 700–1000°C in internally heated pressure vessel (IHPV). Synthetic FeCO3 and natural siderite were used to generate fluid during experiments using a platinum double‐capsule technique. A natural CaTiSiO5 aggregate was placed into the inner capsule as an additional source of trace elements. The outer capsule was loaded with albite glass. No water was introduced to the system and oxygen fugacity was established near to graphite–oxygen (CCO) buffer due to transformation of FeCO3 into a magnetite aggregate during decarbonation to yield CO and CO2. The carbonates decomposed during initial heating of the experiments, causing their some constituent components to be dissolved in and transferred by the fluid to the pore space of the albite glass matrix. After temperature reached 1000°C glass, the shards annealed and then melted, as evidenced by a vesiculated glass in the quench products. Micro‐Raman investigation of the fluid in bubbles in the albite glass in experiments with decomposition of natural siderite yielded CO–CO2 mixture where CO mole fraction was 0.15–0.16. We observe significant concentrations of Pt, Mn, P, and REE in the albite glass; in contrast, no Fe or Mg transfer was detected. LA‐ICP‐MS analysis of the albite glass product yielded the average Pt content of 2 ppm. Such high Pt signal came from Pt particles (100–500 nm in size), which were observed on the walls of the bubbles embedded in the glass. Olivines and aluminous spinel were observed in the Fe‐oxide aggregate, demonstrating transfer of SiO2 and Al2O3 from the albite melt by the reduced carbonic fluid from the albite glass (large capsule). Our results demonstrate that dry CO–CO2 fluid can be important agents of dissolution and transport, especially for Pt and other metals. The data imply that metals are chiefly dissolved as carbonyl complexes.

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“…In addition, a number of recent works have proven the important role of both alkaline carbonate melts in the generation of proto-kimberlite melts [2][3][4][5] and carbon dioxide as the most important mantle fluid component in oxidized domains [6]. The possibility of diamond crystallization in the presence of carbon dioxide is also supported by detection of inclusions containing carbonate [7][8][9] and CO 2 fluid [10] in natural diamonds. Recently, we investigated the effect of P ÀT parameters on diamond crystallization in a CO 2 -rich sodium carbonate melt [11].…”

Section: Introductionmentioning

confidence: 99%