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Published on: April 12, 2017
Field-based Raman spectroscopic analyses of an Ordovician stromatolite
Alison Olcott Marshall1, Craig P Marshall
1Department of Geology, University of Kansas , Lawrence, Kansas.
Astrobiology
|September 11, 2013
Summary
Portable Raman spectrometers analyzed ancient stromatolites, detecting mineralogy and carbon. This demonstrates field analysis capability for Mars missions, suggesting a 785 nm laser may be better for finding fossil biosignatures.
Area of Science:
- Astrobiology
- Geochemistry
- Planetary Science
Background:
- Miniaturized Raman spectrometers are crucial for Mars life-detection missions.
- Field-portable Raman spectrometers have analyzed extant biosignatures but not ancient ones.
Purpose of the Study:
- To assess the capability of portable Raman spectroscopy for analyzing ancient biosignatures in situ.
- To evaluate the effectiveness of different excitation sources for detecting fossilized life.
Main Methods:
- A portable Raman spectrometer with a 785 nm excitation source was used.
- Analysis of an Ordovician stromatolite was performed directly at the outcrop without sample preparation.
Main Results:
- The portable Raman spectrometer successfully identified the mineralogy of the stromatolite.
- The presence of sp² carbonaceous material, indicative of potential biosignatures, was detected.
- The 785 nm excitation source proved effective for analyzing the ancient stromatolite.
Conclusions:
- Field-portable Raman spectroscopy can analyze ancient stromatolites, a key target for Mars missions.
- The findings have significant implications for the design of instruments for future extraterrestrial life detection.
- A 785 nm excitation source may be more suitable than a 532 nm source for detecting fossil biosignatures on Mars.
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