Petrology and mineralogy of the Viñales meteorite, the latest fall in Cuba

Sci Prog. 2021 Apr-Jun;104(2):368504211019859. doi: 10.1177/00368504211019859.

Abstract

The new Cuban chondrite, Viñales, fell on February first, 2019 at Pinar del Rio, northwest of Cuba (22°37'10″N, 83°44'34″W). A total of about 50-100 kg of the meteorite were collected and the masses of individual samples are in a range 2-1100 g. Two polished thin sections were studied by optical microscope, Raman spectroscopy and electron microprobe analysis in this study. The meteorite mainly consists of olivine (Fa24.6), low-Ca pyroxene (Fs20.5), and troilite and Fe-Ni metal, with minor amounts of feldspar (Ab82.4-84.7). Three poorly metamorphosed porphyritic olivine-pyroxene and barred olivine chondrules are observed. The homogeneous chemical compositions and petrographic textures indicate that Viñales is a L6 chondrite. The Viñales has fresh black fusion crust with layered structure, indicating it experienced a high temperature of ∼1650°C during atmospheric entry. Black shock melt veins with width of 100-600 μm are pervasive in the Viñales and olivine, bronzite, and metal phases are dominate minerals of the shock melt vein. The shock features of major silicate minerals suggest a shock stage S3, partly S4, and the shock pressure could be >10 GPa.

Keywords: L6 chondrite; Viñales meteorite; fusion crust; geochemistry; shock effects.

MeSH terms

  • Cuba
  • Meteoroids*
  • Minerals / analysis
  • Minerals / chemistry
  • Spectrum Analysis, Raman

Substances

  • Minerals