Structures/textures of living/fossilmicrobialites and their implications in biogenicity,An astrobiological point of view
Vincenzo Rizzo, Maria Eugenia Farias, Nicola Cantasano, Daniela Billi,Manuel Contreras, Francesca Pontenani,Giorgio Bianciardi
1Geologist, National Research Council, Researcher - retired, Via Repaci 22 Rende Cosenza, (ITALY)
2Biologist, Laboratorio de Investigaciones Microbiológicas de L agunas Andinas (L IML A), Planta Piloto de Procesos Industriales Microbiológicos (PR OIMI ), CCT, C onicet Tucumán, (AR GE NT INA)
3Biologist, National Research Council, Institute for Agricultural and Forest Systems in the Mediterranean, Rende Research Unit, Cosenza, (ITALY)
4Biologist, Dept. of Biology, University of Rome, Tor Vergata, Rome, (ITALY).
5Centro de Ecología Aplicada (CE A), Ñuñoa, Santiago, (CHI L E )
6Biologist, Dpt. Medical Biotechnologies, University of Siena, Siena, (ITALY).
7Biologist and Physician, PhD, Researcher, Dpt. Medical Biotechnologies, University of Siena, Siena, (ITALY).
Atacama’s microbialites, able to live in such extreme environment, are possible candidates as models for searching life in other planets or moons. At present, little is known about their microstructure and composition. This study analyzes, mainly, the terrestrial microstructures in a dimensional field longer than 0.1 mm, through an original approach using photographs and macro pictures, appropriately magnified and consequently little defocused, in comparison with analogous images shot by NASA Rovers on Martian outcroppings. Amethod able to permit comparison of structures and textures of terrestrial microbialites to the microscopic photo images (MI) shot by the cameras mounted on the NASA rovers that since more ten years are present on the Red Planet (Opportunity, Spirit, Curiosity). The study highlights occurrence of widespread structures likes microspherules (or clots), often organized into some higher order settings, such are donuts, polispherules, filaments and, above all, intertwined filaments of microspherules, all showing features of an imperfect geometrical repetitiveness. The structural analysis has been connected with a textural study by a multifractal analysis, that is able to distinguish terrestrial biogenic stromatolites from abiogenic pseudo-stromatolites, and giving us a tool that might be applied for astrobiological purposes.
Atacama; Microbialites; Mars; Microstructural parallels; Multifractal analysis; Extreme environment.