Associations of organic matter with minerals in Tagish Lake meteorite via high spatial resolution synchrotron‐based FTIR microspectroscopy

Abstract

We have investigated spatial and spectral associations between mineral species and organic matter in the Tagish Lake meteorite. Synchrotron‐based infrared microspectroscopy allowed us to spatially locate specific organic and inorganic compounds within multiple Tagish Lake grains with high spatial resolution. Generated two‐dimensional infrared maps present strong spatial association between aliphatic C‐H and OH in phyllosilicates in Tagish Lake grains. These observations indicate possible roles of phyllosilicates for the formation, evolution, and preservation of organic matter. Infared spectra of all studied Tagish Lake grains show a strong carbonate band, which also shows a weak but positive correlation with organic matter in some grains. However, intergrain correlation was not observed between carbonates and organics, which is likely due to the difference of carbonate occurrence, e.g., presence of larger grains or intergrowth of carbonates on phyllosilicates. Possible scenarios further explaining the observed associations of organics with phyllosilicates and carbonates are presented.

Nanoscale infrared imaging analysis of carbonaceous chondrites to understand organic-mineral interactions during aqueous alteration

“…3 C-E) overlap with phyllosilicates. These results are consistent with the previous IR imaging measurements of carbonaceous chondrites that showed an association of OM with phyllosilicates (28,29,31,32), but our results demonstrate this association at much higher spatial resolution. This indicates that the OM is finely mixed with phyllosilicates, and that perhaps OM exists in the interlayer spacings.…”

“…Fourier transform infrared (FTIR) microspectroscopy is a well-established technique for extraterrestrial materials (15)(16)(17)(21)(22)(23)(24)(25)(26)(27), as well as imaging analyses (28)(29)(30)(31)(32). IR spectroscopy provides information about not only molecular structures of OM similar to C-XANES, but also mineral identification, and thus could be a complementary method to STXM/C-XANES.…”

Combining IR and X‐ray microtomography data sets: Application to Itokawa particles and to Paris meteorite

“…Thanks to the recent developments of Fourier transform (FT) IR hyperspectral imaging setups, in particular those using focal plane array (FPA) detectors, FT-IR microtomography has become possible (Martin et al 2013). This technique has been applied on geological and biological samples (Martin et al [2013] with a synchrotron source and Quaroni et al [2015] with a globar source) as well as on one fragment of the Murchison meteorite (Yesiltas et al 2016). IR tomography could be performed on samples with a size between 10 and 60 lm (limited by signal saturation).…”

Nanometre-scale infrared chemical imaging of organic matter in ultra-carbonaceous Antarctic micrometeorites (UCAMMs)

“…Effort has been made to overcome the diffraction limitations imposed by classical Fourier transform IR microspectroscopy analyses (Kebukawa et al 2010;Dominguez et al 2014;Yesiltas & Kebukawa 2016), and preserve the information on chemical functional groups that is complementary to conventional elemental and isotopic mapping provided by electron microscopy and secondary ion mass spectrometry (NanoSIMS). AFMIR provides the spatial resolution mapping capability and is also, if well calibrated, among the best near-field quantitative techniques (Ramer et al 2017).…”