Startseite A new mineral with an olivine structure and pyroxene composition in the shock-induced melt veins of Tenham L6 chondrite
Artikel
Lizenziert
Nicht lizenziert Erfordert eine Authentifizierung

A new mineral with an olivine structure and pyroxene composition in the shock-induced melt veins of Tenham L6 chondrite

  • Zhidong Xie EMAIL logo , Thomas G. Sharp , Kurt Leinenweber , Paul S. DeCarli und Przemek Dera
Veröffentlicht/Copyright: 2. April 2015
Veröffentlichen auch Sie bei De Gruyter Brill

Abstract

We report a new mineral that occurs in shock-induced melt veins of the Tenham L6 chondrite. The new mineral, identified by transmission electron microscopy (TEM), occurs as acicular nanocrystals in a glassy matrix at the edge of shock-induced melt veins that crystallized during rapid quench at high pressure. The elongate crystals have aspect ratios up to 25. Widths range from -5 to -40 nm and lengths are up to 500 nm. Energy-dispersive X-ray spectroscopy (EDS) analyses provide the relative cation abundances that are consistent with a pyroxene-like stoichiometry: Na0.06Ca0.02Mg0.71Fe0.20Al0.11Si0.94O3. Selected area electron diffraction (SAED) patterns from single-crystal and polycrystalline aggregates indicate an olivine structure with refined cell parameters: a = 4.78, b = 10.11, and c = 5.94 Å and a calculated density of 3.32 g/cm3. Synchrotron X-ray microdiffraction data are consistent with an olivine structure and provide similar cell parameters: a = 4.778, b = 10.267, c = 5.937 Å. The pyroxene composition represents a large deviation from olivine stoichiometry, (Na0.08Ca0.03Mg0.95 Fe0.26Al0.15Si0.25□0.28)2Si1O4, with 0.28 formula units of vacancies (□), 0.11 of Na+ plus Ca2+, and 0.25 of Si4+, in octahedral sites. Our observations indicate that a metastable and nonstoichiometric olivine structure can crystallize from a silicate melt during rapid quench. Trace amounts of such defects may be present in stable olivines in the deep upper mantle

Received: 2009-10-30
Accepted: 2010-10-20
Published Online: 2015-4-2
Published in Print: 2011-2-1

© 2015 by Walter de Gruyter Berlin/Boston

Artikel in diesem Heft

  1. Paulscherrerite from the Number 2 Workings, Mount Painter Inlier, Northern Flinders Ranges, South Australia: “Dehydrated schoepite” is a mineral after all
  2. Atomistic investigation of the pyrophyllitic substitution and implications on clay stability
  3. Application of the two-feldspar geothermometer to ultrahigh-temperature (UHT) rocks in the Khondalite belt, North China craton and its implications
  4. Wüstite in a hydrothermal silver-lead-zinc vein, Lucky Friday mine, Coeur d’Alene mining district, U.S.A.
  5. Gelosaite, BiMo6+(2–5x)Mo5+6xO7(OH)·H2O (0 ≤ x ≤ 0.4), a new mineral from Su Senargiu (CA), Sardinia, Italy, and a second occurrence from Kingsgate, New England, Australia
  6. Improved electron probe microanalysis of trace elements in quartz
  7. Ultra-high residual compressive stress (>2 GPa) in a very small volume (<1 μm3) of indented quartz
  8. Transmission electron microscopy investigation of Ag-free lillianite and heyrovskýite from Vulcano, Aeolian Islands, Italy
  9. Combined inelastic neutron scattering and solid-state density functional theory study of dynamics of hydrogen atoms in muscovite 2M1
  10. Contact metamorphism of a Cretaceous accretionary prism by the 14 Ma Okueyama granite, a single post-kinematic pluton in Central Kyushu, Japan: SVD analysis of metamorphic reactions and thermal release
  11. Origin of crosscutting dissolution surfaces in magmatic plagioclase
  12. Néel transition in (Mg,Fe)O: A possible change of magnetic structure
  13. Extreme channelization of fluid and the problem of element mobility during Barrovian metamorphism
  14. The high-temperature P21/m → C2/m phase transitions in synthetic amphiboles along the richterite–(BMg)–richterite join
  15. The crystal structure of barite, BaSO4, at high pressure
  16. Thermal decomposition of brushite, CaHPO4·2H2O to monetite CaHPO4 and the formation of an amorphous phase
  17. Rhombic-shaped nanodomains in columbite driven by contrasting cation order
  18. High-pressure structural evolution and equation of state of analbite
  19. In-situ dehydration studies of fully K-, Rb-, and Cs-exchanged natrolites
  20. The crystal structures and Raman spectra of aravaipaite and calcioaravaipaite
  21. Temperature dependence of the Fe2+ Mössbauer parameters in triphylite (LiFePO4)
  22. Synthesis and characterization of françoisite-(Nd): Nd[(UO2)3O(OH)(PO4)2]·6H2O
  23. Fluorphosphohedyphane, Ca2Pb3(PO4)3F, the first apatite supergroup mineral with essential Pb and F
  24. A new mineral with an olivine structure and pyroxene composition in the shock-induced melt veins of Tenham L6 chondrite
  25. The WURM project—a freely available web-based repository of computed physical data for minerals
  26. Acid production by FeSO4·nH2O dissolution: Comment
  27. Letter. Crystal chemistry of sodium in the Earth’s interior: The structure of Na2MgSi5O12 synthesized at 17.5 GPa and 1700 °C
  28. Letter. In-situ infrared spectra of OH in olivine to 1100°C
Heruntergeladen am 25.9.2025 von https://www.degruyterbrill.com/document/doi/10.2138/am.2011.3437/html
Button zum nach oben scrollen