Organic and inorganic correlations for Northwest Africa 852 by synchrotron‐based Fourier transform infrared microspectroscopy

Abstract

Relationships between organic molecules and inorganic minerals are investigated in a single 34 lm diameter grain of the CR2 chondrite Northwest Africa 852 (NWA) 852 with submicron spatial resolution using synchrotron-based imaging micro-FTIR spectroscopy. Correlations based on absorption strength for the various constituents are determined using statistical correlation analysis. The silicate band is found to be correlated with the hydration band, and the latter is highly correlated with stretching modes of aliphatic hydrocarbons. Spatial distribution maps show that water+organic combination, silicate, OH, and C-H distributions overlap, suggesting a possible catalytic role of phyllosilicates in the formation of organics. In contrast, the carbonate band is anticorrelated with water+organic combination, however uncorrelated with any other spectral feature. The average ratio of asymmetric CH 2 and CH 3 band strengths (CH 2 /CH 3 = 2.53) for NWA 852 is similar to the average ratio of interplanetary dust particles (~2.40) and Wild 2 cometary dust particles (2.50), but it significantly exceeds that of interstellar medium objects (~1.00) and several aqueously altered carbonaceous chondrites (~1.40). This suggests organics of similar length/ branching, and perhaps similar formation regions, for NWA 852, Wild 2 dust particles, and interplanetary dust particles. The heterogeneous spatial distribution of ratio values indicates the presence of a mixture of aliphatic organic material with different length/branching, and thus a wide range of parent body processes, which occurred before the considered grain was formed.

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.…”

Electrodynamic properties of aqueous spray-deposited SnO2:F films for infrared plasmonics

“…[38][39][40][41] Note particularly the broad peak in ε 0 0 at ∼9.4 μm, which is similar to the well-known 9-μm absorption band in silicates. 42 This band becomes weaker with increasing [F]. In A samples grown at 450°C, the overall ε 0 0 curves have lower value, and the 9.4-μm peak is much stronger while retaining the same weakening trend with increasing [F].…”

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

“…, ; Yesiltas et al. , , ), yet it takes highly advanced analytical instrumentation to search for the organics in situ on micron and submicron scales. Here we present synchrotron‐based spatially resolved infrared microspectroscopy of multiple organic‐rich Tagish Lake grains.…”

“…Spatially resolved infrared spectroscopy can (1) reveal locations of organics and minerals in situ within meteorite grains, (2) reveal relationships of organics with specific minerals, and (3) help us understand formation mechanisms and alteration of organics. A little work is being done in this area using IR spectroscopy (Kebukawa et al 2009a(Kebukawa et al , 2010Yesiltas et al 2013Yesiltas et al , 2014Yesiltas et al , 2015, yet it takes highly advanced analytical instrumentation to search for the organics in situ on micron and submicron scales. Here we present synchrotron-based spatially resolved infrared microspectroscopy of multiple organic-rich Tagish Lake grains.…”