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 - 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
UR - http://www.scopus.com/inward/record.url?scp=85068476651&partnerID=8YFLogxK
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 -