Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences—A Review

Abstract

Fourier transform infrared spectroscopy (FTIR) can provide crucial information on the molecular structure of organic and inorganic components and has been used extensively for chemical characterization of geological samples in the past few decades. In this paper, recent applications of FTIR in the geological sciences are reviewed. Particularly, its use in the characterization of geochemistry and thermal maturation of organic matter in coal and shale is addressed. These investigations demonstrate that the employment of high-resolution micro-FTIR imaging enables visualization and mapping of the distributions of organic matter and minerals on a micrometer scale in geological samples, and promotes an advanced understanding of heterogeneity of organic rich coal and shale. Additionally, micro-FTIR is particularly suitable for in situ, non-destructive characterization of minute microfossils, small fluid and melt inclusions within crystals, and volatiles in glasses and minerals. This technique can also assist in the chemotaxonomic classification of macrofossils such as plant fossils. These features, barely accessible with other analytical techniques, may provide fundamental information on paleoclimate, depositional environment, and the evolution of geological (e.g., volcanic and magmatic) systems.

Assessment of Thermal Maturity Trends in Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations of Peak-Fitting Method

“…Vibrational spectroscopy has been evaluated as a potential technique for predicting the thermal maturity of carbonaceous samples (Spotl et al, 1998;Ferrari and Robertson, 2000;Beyssac et al, 2002;Quirico et al, 2005;Rahl et al, 2005;Guedes et al, 2010Guedes et al, , 2012Hinrichs et al, 2014;Wilkins et al, 2014;Zhou et al, 2014;Chen et al, 2015;Bonoldi et al, 2016;Lünsdorf, 2016;Lünsdorf and Lünsdorf, 2016;Sauerer et al, 2017;Schito et al, 2017;Schmidt et al, 2017). Most of this research has focused on Raman spectroscopy, an analytical tool that provides fast, non-destructive analyses, requires little-to-no sample preparation, and can grant both qualitative and quantitative information about the analyte.…”

Quantifying Heterogeneity of Small Test Portion Masses of Geological Reference Materials by Portable XRF Spectrometry: Implications for Uncertainty of Reference Values

“…For example, FTIR (Chen et al 2015) and VIS-NIR (Horta et al 2015) have application as in situ methods that can be used for quantitative measurements in the field. It can reasonably be assumed that other analytical methods that depend on macro-beam methodologies will be similarly affected by analyte heterogeneity.…”

“…It can reasonably be assumed that other analytical methods that depend on macro-beam methodologies will be similarly affected by analyte heterogeneity. For example, FTIR (Chen et al 2015) and VIS-NIR (Horta et al 2015) have application as in situ methods that can be used for quantitative measurements in the field. At the microscale, LA-ICP-MS (Limbeck et al 2015) can be considered as a laboratory-based method that uses beam technology and where measurements may also be affected by heterogeneity of analytes.…”

“…They typically have beam size in the centimetre range, are capable of making quantitative field measurements, and include FTIR, VIS-NIR and PXRF (Chen et al 2015, Horta et al 2015. They typically have beam size in the centimetre range, are capable of making quantitative field measurements, and include FTIR, VIS-NIR and PXRF (Chen et al 2015, Horta et al 2015.…”

“…A range of portable 'macro-beam' analytical devices has been developed in the last 10 years. They typically have beam size in the centimetre range, are capable of making quantitative field measurements, and include FTIR, VIS-NIR and PXRF (Chen et al 2015, Horta et al 2015. One example of this trend towards acquiring rapid measurements in the field is an increasing use of portable X-ray fluorescence (PXRF) instruments (for brevity, the acronym PXRF is used to represent 'hand-held' XRF throughout the text).…”