# Chelyabinsk : a rock with many different (stony) faces: An infrared study

**Authors:** Andreas Morlok, Addi Bischoff, Markus Patzeck, Martin Sohn, Harald Hiesinger  
**arXiv:** [2301.06525](https://arxiv.org/abs/2301.06525)  
**Date:** 2023-01-16  
**Summary page:** https://www.summarizepaper.com/en/paper/2301.06525v1/

## Key points

- Study aimed to provide spectral ground truth data for remote sensing applications by measuring mid-infrared spectra of three distinct lithologies from the Chelyabinsk meteorite
- Three identified lithologies: moderately shocked, light lithology; shock darkened lithology; impact melt lithology
- Analyses conducted on bulk material in four size fractions and additional thin sections
- Characteristic infrared features observed in the powdered bulk material of the moderately shocked, light lithology primarily composed of olivine, pyroxene, and feldspathic glass
- Impact shock processes found to significantly alter the infrared characteristics of meteoritic materials, leading to changes in spectral features such as loss of crystal structure

## Summary

In their study titled "Chelyabinsk: a rock with many different (stony) faces: An infrared study," Andreas Morlok, Addi Bischoff, Markus Patzeck, Martin Sohn, and Harald Hiesinger aimed to provide spectral ground truth data for remote sensing applications by measuring mid-infrared spectra (2 to 18 microns) of three distinct lithologies from the Chelyabinsk meteorite. These lithologies were identified as (a) moderately shocked, light lithology, (b) shock darkened lithology, and (c) impact melt lithology. The analyses were conducted on bulk material in four size fractions ranging from 0 to 250 microns and additional thin sections. The researchers observed characteristic infrared features in the powdered bulk material of the moderately shocked, light lithology which was primarily composed of olivine, pyroxene and feldspathic glass. The  conducted by Morlok et al. focused on providing valuable insights into the  of the Chelyabinsk meteorite. By analyzing mid-infrared spectra of three distinct lithologies - , , and , they aimed to gather spectral ground truth data for remote sensing applications. The results showed that as the influence of impact shock increased from pristine LL5 or LL6 materials towards the shock-darkened lithology and impact melt endmembers, there was a noticeable fading or disappearance of spectral features. This included a loss of a twin peak feature between 10.8 and 11.3 microns which transitioned into a single peak as well as losses at approximately 9.6 microns and about 9.1 microns in the pure impact melt endmember lithology. The  were found to significantly alter the infrared characteristics of meteoritic materials, leading to changes in spectral features such as the loss of crystal structure. This study provides valuable insights into how shock processes can affect the  of meteorites, particularly those from the Chelyabinsk meteorite.