TY - JOUR
T1 - Organic matter preservation and incipient mineralization of microtubules in 120 Ma basaltic glass
AU - Izawa, Matthew R.M.
AU - Dynes, James J.
AU - Banerjee, Neil R.
AU - Flemming, Roberta L.
AU - MacLean, Lachlan C.W.
AU - Hetherington, Callum J.
AU - Matveev, Sergei
AU - Southam, Gordon
N1 - Funding Information:
MI acknowledges funding from the Natural Sciences and Engineering Research Council of Canada (NSERC), Mineralogical Association of Canada, Canada IODP, and the Canadian Astrobiology Training Program. NB, RF, and GS acknowledge funding from the NSERC.
Publisher Copyright:
© 2019 Izawa, Dynes, Banerjee, Flemming, MacLean, Hetherington, Matveev and Southam.
PY - 2019/6/18
Y1 - 2019/6/18
N2 - Hollow tubular structures in subaqueously-emplaced basaltic glass may represent trace fossils caused by microbially-mediated glass dissolution. Mineralized structures of similar morphology and spatial distribution in ancient, metamorphosed basaltic rocks have widely been interpreted as ichnofossils, possibly dating to ∼3.5 Ga or greater. Doubts have been raised, however, regarding the biogenicity of the original hollow tubules and granules in basaltic glass. In particular, although elevated levels of biologically-important elements such as C, S, N, and P as well as organic compounds have been detected in association with these structures, a direct detection of unambiguously biogenic organic molecules has not been accomplished. In this study, we describe the direct detection of proteins associated with tubular textures in basaltic glass using synchrotron X-ray spectromicroscopy. Protein-rich organic matter is shown to be associated with the margins of hollow and partly-mineralized tubules. Furthermore, a variety of tubule-infilling secondary minerals, including Ti-rich oxide phases, were observed filling and preserving the microtextures, demonstrating a mechanism whereby cellular materials may be preserved through geologic time.
AB - Hollow tubular structures in subaqueously-emplaced basaltic glass may represent trace fossils caused by microbially-mediated glass dissolution. Mineralized structures of similar morphology and spatial distribution in ancient, metamorphosed basaltic rocks have widely been interpreted as ichnofossils, possibly dating to ∼3.5 Ga or greater. Doubts have been raised, however, regarding the biogenicity of the original hollow tubules and granules in basaltic glass. In particular, although elevated levels of biologically-important elements such as C, S, N, and P as well as organic compounds have been detected in association with these structures, a direct detection of unambiguously biogenic organic molecules has not been accomplished. In this study, we describe the direct detection of proteins associated with tubular textures in basaltic glass using synchrotron X-ray spectromicroscopy. Protein-rich organic matter is shown to be associated with the margins of hollow and partly-mineralized tubules. Furthermore, a variety of tubule-infilling secondary minerals, including Ti-rich oxide phases, were observed filling and preserving the microtextures, demonstrating a mechanism whereby cellular materials may be preserved through geologic time.
KW - Basaltic glass
KW - Biomolecule
KW - Ichnofossils
KW - Ontong Java Plateau
KW - Synchrotron XANES
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U2 - 10.3389/feart.2019.00149
DO - 10.3389/feart.2019.00149
M3 - Article
AN - SCOPUS:85068476651
SN - 2296-6463
VL - 7
JO - Frontiers in Earth Science
JF - Frontiers in Earth Science
M1 - 149
ER -