Chemical and structural composition of organic carbonaceous structures in Tissint: evidence for a biogenetic origin

Jamie Wallis; N. C. Wickramasinghe; Daryl H. Wallis; Nori Miyake; M. K. Wallis; Richard B. Hoover

doi:10.1117/12.2186515

22 September 2015 Chemical and structural composition of organic carbonaceous structures in Tissint: evidence for a biogenetic origin

Jamie Wallis, N. C. Wickramasinghe, Daryl H. Wallis, Nori Miyake, M. K. Wallis, Richard B. Hoover

Author Affiliations +

Proceedings Volume 9606, Instruments, Methods, and Missions for Astrobiology XVII; 96060L (2015) https://doi.org/10.1117/12.2186515
Event: SPIE Optical Engineering + Applications, 2015, San Diego, California, United States

Abstract

Earlier studies of the Tissint Martian meteorite identified the presence of a number of 5-50μm carbonaceous spherical structures. SEM and EDS elemental spectra for 11 selected structures confirmed that they comprise of a carbonaceous outer coating with a inner core of FeS₂ (pyrite) and are characterised as immiscible globules with curved boundaries. Here we report on the results of Raman spectroscopic studies that unambiguously confirm the mantle as comprising of ‘disordered carbonaceous material’. R1 = I_D/I_G against Γ_D (cm^-1) band parameter plots of the carbonaceous coatings imply a complex precursor carbon inventory comparable to the precursor carbon component of materials of known biotic source (plants, algae, fungi, crustaceans, prokaryotes). Correlation between peak metamorphic temperatures and Raman D-band (Γ_D) parameters further indicate the carbonaceous component was subjected to a peak temperature of ~250 ^OC suggesting a possible link with the hydrothermal precipitation processes responsible for the formation of similar globules observed in hydrothermal calcite veins in central Ireland. Ω _G (cm^-1), Γ_G (cm^-1), Ω _D (cm^-1) and Γ_D (cm^-1) parameters further imply a level of crystallinity and disorder of the carbon component consistent with carbonaceous material recovered from a variety of non-terrestrial sources. Cl, N, O and S to C elemental ratios are typical of high volatility bituminous coals and distinctly higher than equivalent graphite standards.

Citation Download Citation

Jamie Wallis, N. C. Wickramasinghe, Daryl H. Wallis, Nori Miyake, M. K. Wallis, and Richard B. Hoover "Chemical and structural composition of organic carbonaceous structures in Tissint: evidence for a biogenetic origin", Proc. SPIE 9606, Instruments, Methods, and Missions for Astrobiology XVII, 96060L (22 September 2015); https://doi.org/10.1117/12.2186515

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
12 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Raman spectroscopy

Carbon

Crystals

Organic materials

Spectroscopy

Chlorine

Gallium

Show All Keywords

Keywords/Phrases

Search In:

Publication Years