Preservation of organic matter on Mars by sulfur

Abstract : Deltaic-lacustrine mudstones at Pahrump Hills, Gale Crater, Mars yielded a variety of sulfur-containing volatiles upon heating to 500-860°C, as detected by the Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover. The detection of organosulfur compounds comprising thiophenes, dimethylsulfide and thiols by gas chromatography-mass spectrometry and evolved gas analyses, together with aromatic and other hydrocarbon molecules with distributions specific to the sample (i.e., not from the SAM background) indicate that some or all of these organic fragments released at high temperatures are indigenous to the mudstones. The organosulfur compounds are most likely derived from sulfur organics in the sediments. However, there is a possibility that sulfurization of some organic fragments occurred in the oven. On Earth, sulfurization of organic matter is a key process that aids preservation over geological time-scales. This is because it reduces reactive functional groups and adds cross links between small unstable molecules thereby converting them into recalcitrant macromolecules. Sulfurization of organic materials prior to deposition and during early diagenesis may have been a key mechanism responsible for organic matter preservation in the Murray formation mudstones. Sulfur-bearing organics have also been observed in carbonaceous meteorites and there is indication of their presence in the Tissint martian meteorite. A quantitative assessment of organosulfur compounds relative to their non-organic counterparts will be presented for the Murray formation mudstones analyzed by SAM and meteorites analyzed in the laboratory under similar analytical conditions.
Complete list of metadatas

https://hal-insu.archives-ouvertes.fr/insu-01425740
Contributor : Catherine Cardon <>
Submitted on : Tuesday, January 3, 2017 - 6:39:58 PM
Last modification on : Tuesday, June 11, 2019 - 11:12:02 PM

Identifiers

  • HAL Id : insu-01425740, version 1

Citation

Jennifer L. Eigenbrode, Andrew Steele, Roger E. Summons, Amy Mcadam, Brad Sutter, et al.. Preservation of organic matter on Mars by sulfur. AGU Fall Meeting 2016, Dec 2016, San Francisco, United States. pp.P21D-08. ⟨insu-01425740⟩

Share

Metrics

Record views

319