INVESTIGADORES
ZARATE marcelo Aristides
artículos
Título:
Preserved fl ora and organics in impact melt breccias
Autor/es:
PETER H. SCHULTZ; R. SCOTT HARRIS; S.J. CLEMETT; K.L. THOMAS KEPTHRA; MARCELO ZÁRATE
Revista:
GEOLOGY
Editorial:
GEOLOGICAL SOC AMER, INC
Referencias:
Lugar: Boulder; Año: 2014 vol. 42 p. 515 - 518
ISSN:
0091-7613
Resumen:
Impact cratering can destroy life from local to global scales and result in sudden turnovers of dominant genera or species. Here we report that can also preserve components of the local biology present at the time of the impact.We have investigated floral matter encapsulated within Cenozoic era impact glasses. produced by
separate bolide impacts into the loessoid sediments of Argentina that
occurred between 9.2 Ma (Miocene) and 6 ka (Holocene). The encapsulation
preserved not only macro-scale morphological biosignatures
such as vascular bundles, veins, phytoliths, and papillae, but also
structures down to the cellular level. In the best-preserved samples
we also found evidence for organic matter. While fossilization typically
occurs over an extended time period as minerals slowly replace
organic matter and the host rock lithifi es under pressure, the process
documented here is instantaneous. Preservation of morphological
and chemical biosignatures in impact events can provide snapshots of
the ecology in environments that do not otherwise promote a diverse
fossil record. We suggest that this would provide a new strategy for
identifying signs of possible early life on ancient Mars, where similar
target conditions once existed