Intra-microstructures of FeNi Metal in Eutectic Blobs



Our SEM and TEM studies revealed that the dendrites in FeNi–FeS eutectic nodules/blobs in both shock-produced melt veins and melt pockets of the Yanzhuang meteorite show zoning in their microstructures, which indicates non-equilibrium solidification of metal phase. In melt veins, three asymmetric microstructural and compositional zones: core, Ni-rich rim and martensite between the core and ring were discovered, while in melt pockets, a typical symmetric core-crust microstructure consisting of martensitic interiors and Ni-rich rim was revealed. It is suggested that the difference in cooling rates following shock-induced high-temperature melting might be an important factor in producing different dendritic microstructures in melt veins and melt pockets. The solidification environment might be considered as the second influence factor.


FeNi metal Eutectic blob Dendrite Zoning microstructure Martensite 


  1. Begemann F, Wlotzka F (1969) Shock induced thermal metamorphism and mechanical deformation in the Ramsdorf chondrite. Geochim Cosmochim Aata 33:1351–1370CrossRefGoogle Scholar
  2. Blau PJ, Goldstein JI (1975) Investigation and simulation of metallic spherules from lunar soils. Geochim Cosmochim Acta 39:305–324CrossRefGoogle Scholar
  3. Budka PZ (1988) Meteorites as specimens for microgravity research. Metall Trans A 19(A):343–358CrossRefGoogle Scholar
  4. Chen M (1992) Micromineralogy and shock effects in Yanzhuang chondrite (H6). Ph.D. thesis, The Institute of Geochemistry, Chinese Academy of Sciences, p 95 (in Chinese with English abstract)Google Scholar
  5. Chen M, Xie XD (1995) TEM microstructures of the metallic mendrites in the shock-induced melt pocket of the Yanzhuang meteorite. Neues Jahrbuch für Mineralogie 8:337–343Google Scholar
  6. Chen M, Xie XD, El Coresy A (1995) Nonequilibrium solidification and microstructures of metal phases in the shock induced melt of the Yanzhuang (H6) chondrite. Meteoritics 30:28–32CrossRefGoogle Scholar
  7. Kubaschewski O (1982) Iron-binary phase diagrams. Springer-Verlag, Berlin Heidelberg New York, pp 73–182Google Scholar
  8. Scott ERD (1982) Origin of rapidly solidified metal-troilite grains in chondrites and iron meteorites. Geochim Cosmochim Aata 46:813–823CrossRefGoogle Scholar
  9. Smith BA, Goldstein JF (1977) The metallic microstructures and thermal histories of severely reheated chondrites. Geochim Cosmochim Aata 41:1061–1072CrossRefGoogle Scholar
  10. Stöffler D, Keil K, Scott ERD (1991) Shock metamorphism of ordinary chondrites. Geochim Cosmochim Acta 55:3845–3867CrossRefGoogle Scholar
  11. Taylor GJ, Heymann D (1971) Postshock thermal histories of reheated chondrites. J Geophys Res 76:1879–1893CrossRefGoogle Scholar
  12. Thomas MO (1975) Experimental approach to the state of the Core Part 1. The liquidus relations of the Fe-rich portion of the Fe-Ni-S system from 30 to 100 Kb. Am J Sci 275:278–290CrossRefGoogle Scholar
  13. Wilkening LL (1978) Tysnes island: an unusual clast composed of solidified immiscible Fe-FeS and silicate melts. Meteoritics 13:1–9CrossRefGoogle Scholar
  14. Xie XD (1973) Brief introduction of shock metamorphism. Geol Geochem 1:4–6Google Scholar
  15. Xie XD, Chen M (2018) Yanzhuang meteorite: mineralogy and shock metamorphism. Guangdong Science & Technology Press, Guangzhou, p 202 (in Chinese with English abstract)Google Scholar
  16. Xie XD, Huang WK (1991) Thermal and collision history of Jilin (H5) and Qingzhen (EH3) chondrites. Chin J Geochem 10:109–119CrossRefGoogle Scholar

Copyright information

© Guangdong Science & Technology Press Co., Ltd and Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhouChina

Personalised recommendations