Cathodoluminescence microscopy and spectroscopy of forsterite from Kaba meteorite: An application to the study of hydrothermal alteration of parent body

Abstract

Abstract-Highly forsteritic olivine (Fo: 99.2-99.7) in the Kaba meteorite emits bright cathodoluminescence (CL). CL spectra of red luminescent forsterite grains have two broad emission bands at approximately 630 nm (impurity center of divalent Mn ions) in the red region and above 700 nm (trivalent Cr ions) in the red-IR region. The cores of the grains show CL blue luminescence giving a characteristic broad band emission at 400 nm, also associated with minor red emissions related to Mn and Cr ions. CL color variation of Kaba forsterite is attributed to structural defects. Electron probe microanalyzer (EPMA) analysis shows concentrations of Ca, Al, and Ti in the center of the forsterite grain. The migration of diffusible ions of Mn, Cr, and Fe to the rim of the Kaba meteoritic forsterite was controlled by the hydrothermal alteration at relatively low temperature (estimated at about 250°C), while Ca and Al ions might still lie in the core. A very unusual phase of FeO (w€ ustite) was also observed, which may be a terrestrial alteration product of FeNi-metal.

Chondrules as direct thermochemical sensors of solar protoplanetary disk gas

“…Comparisons of the panchromatic CL images with high-resolution x-ray elemental area maps together with hyperspectral scans and individual spectra ( Fig. 2B and section S2) ( 13 – 15 ) reveal that panchromatic CL intensity in Mg-rich olivines is overwhelmingly controlled by their Al concentration: The higher the panchromatic CL intensity, the higher their Al concentration (section S2). In terrestrial olivines, Al occurs at minor to trace levels (tens to hundreds of parts per million), and Al in Mg-rich olivines in chondrules is highly variable with concentrations up to 0.6 weight % (wt %) Al 2 O 3 (table S1) ( 10 , 16 ).…”

Alteration processes in the CV chondrite parent body based on analysis of NWA 2086 meteorite

“…The alteration could be analyzed by detailed mineral study of the meteorites and also by cathodluminescence method, as suggested recently (Gucsik et al. ).…”

Possible Thermoluminescence of the Solid Cometary Substance: Thermoluminescence of Cometary Substance

“…However, the accumulation and release of the absorbed energy in the conditions of the increasing temperature of the substance (e.g., approach of a comet to the perihelion) may have either a synchronic or an asynchronic nature with a certain value of delay. In addition, the thermoluminescence spectra of a number of minerals, including forsterite, obtained by Koike et al (2002aKoike et al ( , 2002bKoike et al ( , 2006 with the first approach, are similar to the spectra of the cathodoluminescence of the same minerals (Gucsik et al 2013). The cathodoluminescence of the forsterite micrograins caused by fast-electron fluxes may also occur spectrally in the form of two bands of emission in the blue and red areas of the optical spectrum.…”