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Title: Imaging of Vanadium in Microfossils: A New Potential Biosignature

Being able to distinguish unambiguously the biogenicity of microfossil-like structures in the ancient rock record is a fundamental predicament facing Archean paleobiologists and astrobiologists. Therefore, novel methods for discriminating biological from non-biological chemistries of microfossil-like structures are of the utmost importance in the search for evidence of early life on Earth. This too, is important for the search for life on Mars; either by in situ analyses via rovers, or sample return missions for future analysis here on Earth. Here, we report the application of synchrotron X-ray fluorescence imaging of vanadium, within thermally altered organic-walled microfossils of bona fide biological origin. From our data, we demonstrate that vanadium is present within microfossils of undisputable biological origin. It is well known in the organic geochemistry literature, that elements such as vanadium are enriched and contained within crude oils, asphalts, and black shales that have been formed by diagensis of biological organic material. It has been demonstrated that the origin of vanadium is due to the diagenetic alteration of precursor chlorophyll and heme porphyrin pigment compounds from living organisms. Here, we propose that taken together, microfossil-like morphology, carbonaceous composition, and the presence of vanadium could be used in tandem as a biosignaturemore » to ascertain the biogenecity of putative microfossil-like structures.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [3] ;  [4] ;  [5] ;  [2]
  1. Univ. of Kansas, Lawrence, KS (United States)
  2. The Univ. of Sydney, NSW (Australia)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Saudi Aramco, Dhahran (Saudi Arabia)
  5. Univ. of Liege, Liege (Belgium)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Astrobiology
Additional Journal Information:
Journal Volume: 17; Journal Issue: 11; Journal ID: ISSN 1531-1074
Publisher:
Mary Ann Liebert, Inc.
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
Australian Research Council; National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; Biosignature; Microfossils; Synchrotron micro-X-ray fluorescence; Tetrapyrrole; Vanadium
OSTI Identifier:
1436103