[Geoinfo] Difusión - Conferencia: "TURBULENT LIFESTYLE: CYANOBACTERIA ON EARTH'S SANDY BEACHES, TODAY AND 3 BILLION YEARS AGO" - Nora Noffke

[Carrera de Doctorado de Geologia]

Estimados,

En el marco del curso de Posgrado "Geobiología aplicada a procesos
sedimentarios costeros. Ambiente actual" dictado por la Dra Diana G.
Cuadrado y colaboradores, inscripto en el Dto. de Geología y Secretaría
General de Posgrado y Educación Continua de la Universidad Nacional del
Sur, los invitamos el martes 8 de junio 17:00 hs. por medio de plataforma
Zoom (
https://us02web.zoom.us/j/83336562079?pwd=ajJHTTVzZG9UNytxNHIxU1hMMHN2dz09)

                                        CONFERENCIA
                                        NORA NOFFKE
Old Dominion University, Norfolk, VA 23529, nnoffke en odu.edu


Turbulent lifestyle: Cyanobacteria on Earth's sandy beaches - today and 3
billion years ago

Modern benthic cyanobacteria are very well adapted to the harsh hydraulic
conditions of sandy tidal environments. The microbial interaction with the
physical sediment dynamics originates the characteristic ‘microbially
induced sedimentary structures (MISS)’. The structures do not resemble
stromatolites at all, and have been classified as their own group of
structures.
MISS occur not only today, but they are abundant in shallow-marine
sandstones of all Earth ages including the early Archean time. A fossil
tidal flat preserved in the 2.9 billion years old Archean Pongola
Supergroup, South Africa, corresponds to the tidal flats that today form
along the coast of the North Atlantic Ocean. This ancient tidal flat
includes microbial mat-related structures of exceptional beauty. Those MISS
record the same types of microbial mats as we find today in our modern
tidal environments. The fossil MISS have in statistical analyses the same
geometries and dimensions like the modern ones. The fossil MISS include
microstructures that are identical to the microstructures in the modern
MISS. The fossil MISS have the same pattern of distribution within the
ancient tidal flats like the modern MISS in equivalent modern tidal flats.
We conclude that the complicated biotic-physical processes that lead to the
specific MISS and their typical distribution cannot be mimicked by the
activities of other prokaryotes than cyanobacteria. Therefore, the
microbial mats of the Pongola Supergroup may include the oldest known
cyanobacteria in Earth's history. Their high diversity suggests a much
earlier start of evolution of cyanobacteria than assumed before.

https://www.youtube.com/watch?v=rEjPiKdqxX4&authuser=1


Saludos,


Cometto Facundo Javier

Secretario

Doctorado en Ciencias Geológicas

Facultad de Ciencias Exactas, Físicas y Naturales

Universidad Nacional de Córdoba

Av. Vélez Sarsfield 1611

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