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Origin And SIgnificance of Stromatolites of the Dead Sea (OASIS)

English title Origin And SIgnificance of Stromatolites of the Dead Sea (OASIS)
Applicant Ariztegui Daniel
Number 188571
Funding scheme Project funding
Research institution Department of Earth Sciences University of Geneva
Institution of higher education University of Geneva - GE
Main discipline Geology
Start/End 01.01.2020 - 31.12.2022
Approved amount 332'720.00
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All Disciplines (2)

Discipline
Geology
Geochemistry

Keywords (3)

Dead Sea; Hypersaline; Stromatolites

Lay Summary (French)

Lead
OASIS est un projet pluridisciplinaire s’organisant autour d’une question principale : Quelles sont les conditions et caractéristiques permettant la formation et préservation des stromatolites dans l’environnement extrême de la Mer Morte ?Les stromatolites représentent certaines des plus anciennes formes de vie sur Terre. Ils comportent des informations sur les conditions au sein desquels la vie primitive s’est développées, et sont pour cette raison l’objet de recherches pour comprendre l’apparition de la vie sur Terre. Toutefois, ces structures sont difficiles à interpréter, tant elles sont le résultat d’interactions complexes ayant lieu à différentes échelles entre monde vivant et monde minéral. Leur étude nécessite donc une approche pluridisciplinaire prenant en compte une caractérisation minéralogique et microbienne à haute résolution.
Lay summary

Nous suggérons d’exploiter les conditions uniques du bassin de la Mer Morte, afin d’y étudier les tapis microbiens et stromatolites vivants et fossilisés. Cela nous permettra de :

1/ contraindre les conditions permettant la formation des tapis microbiens et microbialites

2/ extrapoler ces conditions au registre géologique pour contraindre les conditions environnementales dominantes ayant mené à la préservation des stromatolites fossiles dans le bassin de la Mer Morte, et dans d’autres environnements hypersalins.

Suite à la baisse du niveau de la Mer Morte, de nombreux stromatolites fossiles sont maintenant exposés, et des tapis microbiens se développent aux niveaux des sources d’eaux douces en bordure du lac, pouvant ainsi mener à la formation de nouveaux stromatolites. Nous suggérons donc d’échantillonner ces tapis microbiens modernes. Nous décrirons et monitorerons les communautés qu’ils hébergent en couplant des méthodes de biologie moléculaire, d’imagerie haute résolution et des micro-capteurs, afin de comprendre comment leur activité peut mener à la formation et la préservation de biosignatures. Cette étude s’organisera en deux grands axes : le premier se concentrera sur les conditions expérimentées sur le terrain, le second testera l’influence des paramètres intrinsèques et extrinsèques menant à la formation de microbialites en laboratoire.

Afin d’assurer un ancrage fort avec le terrain, cartographie et description des stromatolites anciens seront réalisés en collaboration avec des équipes de l’université hébraïque de Jérusalem, et l’université An-Najah de Naplouse, en Cisjordanie. Cela permettra de retracer l’histoire limnologique, biologique et géochimique des lacs ayant occupé le bassin de la Mer Morte à différentes périodes du Quaternaire, et mènera à la caractérisation des biosignatures spécifiques à ces structures. Le tout permettra de faire progresser notre compréhension de l’impact des communautés microbiennes sur l’environnement de la Mer morte, et apportera des informations multi-échelles des paramètres menant au développement de stromatolites en conditions extrêmes.

Direct link to Lay Summary Last update: 04.12.2019

Responsible applicant and co-applicants

Employees

Project partner

Associated projects

Number Title Start Funding scheme
149221 Dead Sea Deep Drilling Project: The Swiss contribution (DSDDP-CH) - Phase II 01.12.2013 Project funding
155927 From Satellites to Molecules (SAM): Strategies and tools for reconstructing Late Pleistocene climate in northeastern Patagonia 01.04.2015 Project funding

Abstract

OASIS is a multidisciplinary project organised around one main question: What are the conditions and characteristics allowing the formation and preservation of stromatolites in the extreme Dead Sea environment? The Dead Sea is the most saline lake on Earth. Its water level is currently decreasing by more than one meter per year, and continuously increasing its salinity. Only unicellular organisms manage to survive in this environment. However, at some locations of the current Dead Sea shore flourish active and diverse microbial communities. This is allowed by the resurgence of freshwater springs, providing more favorable (less saline) conditions for the development of life.In the geological past, the Dead Sea Basin (DSB) hosted more auspicious conditions, which allowed the wider development of similar microbially-rich environments, preserved under the form of stromatolites. Stromatolites and thrombolites (gathered here under the term “microbialites”) represent some of the most ancient forms of life on Earth. They bear information on the primitive conditions in which the early life has developed and are thoroughly investigated to understand the appearance of life on Earth. However, the formation of these structures remains incompletely understood, as it is driven by a set of complex microbe-mineral interaction at multiple scales. Their study often necessitates multidisciplinary approaches involving high resolution mineralogical and microbial characterisation. Comparison of ancient stromatolites with their present analogs is therefore critical as it allows in situ investigation of the processes underlying the mineralization and preservation of microbialites. We suggest to exploit the unique conditions occurring in the Dead Sea Basin to investigate living and fossilised microbial mats and stromatolites. This will allow us to:1/ Constrain the conditions enabling the formation of microbial mats and microbialites.2/ Extrapolate such conditions to the geological record to compel the dominant paleoenvironmental conditions that have led to the preservation of fossil stromatolites in the Dead Sea Basin, and in other hypersaline environments.The Dead Sea provides a very favorable environment for such study. The lake level retreat has exposed numerous ancient stromatolitic structures. Where freshwater springs occur, microbial mats develop and may also be preserved in microbialites. The intense rates of precipitation, and the strong environmental dynamics at stake in this extreme environment provide a unique setting for investigating active microbe-mineral interactions. We suggest to collect modern microbial mats from various springs at the current Dead Sea shore. Microbial mat communities will be described and monitored using molecular biology coupled to high resolution imaging and microsensing techniques, to understand how their activity can lead to the formation and preservation of biosignatures. Such study will be implemented along two axes. The first one will focus on the conditions experienced on the field. The second one will test for the influence of internal and external parameters on the formation of microbialites under laboratory-controlled conditions.To ensure a strong anchoring with the Dead Sea environment, a parallel mapping and description of ancient stromatolites will be carried out. It will allow to retrace the limnological, biological and geochemical history of the paleo-lakes that occupied the Dead Sea Basin at different time intervals, and should lead to the characterisation of the biosignatures specific to these structures. This will be realised in collaboration with a local team of field geology, paleolimnology and geochemistry experts from the Hebrew University of Jerusalem in Israel (HUJI) and the An-Najah University in Nablus in the West Bank Palestinian Territories. The completion of these parallel modules will advance our knowledge on the patterns of formation and preservation of microbial activity in the unique environment of the Dead Sea, and bring novel multiscale understanding on the parameters leading to stromatolitic development in extreme environments.
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