Article Metrics


Online attention

Investigating the history of volatiles in the solar system using synchrotron infrared micro-spectroscopy

DOI: 10.1016/j.infrared.2018.09.020 DOI Help

Authors: Ashley J. King (Natural History Museum) , Paul F. Schofield (Natural History Museum) , Natasha R. Stephen (University of Plymouth) , Mark D. Frogley (Diamond Light Source) , Gianfelice Cinque (Diamond Light Source) , Sara S. Russell (Natural History Museum)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Infrared Physics & Technology

State: Published (Approved)
Published: September 2018
Diamond Proposal Number(s): 9614

Open Access Open Access

Abstract: The aqueously altered CM carbonaceous chondrite meteorites can be used to investigate the nature and transport of volatiles in the early solar system. We present the preliminary results of an effort to collect 2D infrared (IR) spectral maps from the matrix and fine-grained rims (FGRs) of material that surround chondrules and inclusions in the Murchison CM2 meteorite using synchrotron IR micro-spectroscopy. The main features in mid-IR spectra of the matrix and FGRs occur at ∼3500 cm-1 and ∼1000 cm-1 and are attributed to -OH/H2O and Si-O bonds in phyllosilicates and anhydrous silicates. Minor features in the spectra are attributed to organic species (3000–2800 cm-1), CO2 (2400 – 2000 cm-1), and carbonates (1500 – 1380 cm-1). In both the matrix and FGRs we observe correlations between the -OH/H2O and phyllosilicate/silicate features confirming that phyllosilicates dominate the mineralogy. This is consistent with previous studies showing that Murchison contains ∼70 vol% phyllosilicates following aqueous alteration on an asteroid parent body. The presence of anhydrous silicates in the matrix indicates that the alteration was heterogeneous at the micron-scale and that the reactions did not reach completion. We highlight a possible correlation between the phyllosilicates and organic species in the matrix, supporting the hypothesis that phyllosilicates may have played an important role in the formation and preservation of simple organic molecules and compounds. In the FGRs variations in the distribution of the phyllosilicate minerals cronstedtite and Mg-serpentine/saponite likely reflect differences in the local geochemical conditions during aqueous alteration on the asteroid.

Journal Keywords: Synchrotron infrared micro-spectroscopy; CM chondrite meteorite; Murchison; aqueous alteration; asteroids

Subject Areas: Chemistry, Earth Science

Instruments: B22-Multimode InfraRed imaging And Microspectroscopy