Investigating the Hydration of CM2 meteorites by IR spectroscopy

TL;DR

This study uses FT-IR spectroscopy to analyze the hydration levels of CM2 meteorites, developing a new pellet method to accurately measure water content and hydration extent in these ancient solar system remnants.

Contribution

A novel pellet production technique was developed to eliminate environmental water, enabling more precise FT-IR analysis of hydrated CM2 meteorites.

Findings

Water content and hydration extent can be accurately determined from IR spectra.

The new pellet method reduces interference from adsorbed environmental water.

FT-IR spectroscopy effectively characterizes aqueous alteration in meteorites.

Abstract

Chondritic meteorites are of great interest since they are one of the most ancient remnants of the early solar system. Some of them, like the carbonaceous CM meteorites experienced aqueous alteration thus their olivine content transformed more or less into hydrated silicates such as phyllosilicates. These hydrated CM2 meteorites have been investigated in KBr pellets by means of Fourier transform infrared (FT-IR) spectroscopy. In our focus of interest was to study the 3 and 10 $\mu$m (3000 and 1000 cm$^{-1}$, the O$-$H and silicate streching) bands of several CM2 chondrites. By investigating these signals the water content and the extent of hydration can be determined. In order to achieve this, development of a new pellet production method was essential. This technique facilitates the elimination of adsorbed water coming from the surrounding environment, which would complicate correct interpretation of the results.