Axis 4

Sediment, Source 2 Sink, Mud 2 Mantle, transport processes, record, vertical movement, deep structure, deep processes

Coordinators

Marina RABINEAU (LDO/IUEM), Samuel TOUCANNE (GM/Ifremer)

Daniel ASLANIAN (GM/Ifremer), Pascal LE ROY (LDO/IUEM)

Participating laboratories

LDO (Laboratoire Domaines Océaniques) UBO, CNRS/INSU
GM (Laboratoire de Géosciences Marines) Ifremer
DYNECO (Département dynamiques de l’environnement côtier) Ifremer
LEMAR (Laboratoire des sciences de l'environnement marin) UBO, CNRS, IRD
LM2E (Laboratoire Microbiologie des Environnements Extrêmes) Ifremer, UBO, CNRS/INEE

Scientific context

Mountains building and their erosion, sediment transfers through rivers into continental plate-forms and deep oceans, are deeply connected with the growth cycle of the earth. Sedimentary processes occurring along continental margins are complex and only partially known, they result from the interaction between deep processes (tectonics with subsidence/uplift) and surficial processes (climate and sea level changes, hydrodynamics). Probing the strong correlation between deep and surface processes in order to understand the Earth growing and to model forecasts needs multidisciplinary approach. Axis 4 aims at reconstructing 4D sedimentary fluxes from source to sink zones and their consequences on long term margin architecture building.

Roadmap

The main objective of axis 4 is to understand and quantify, using marine sediment archives, all changes related to natural parameters (climate, sea level, hydrodynamic and paleoceanography, tectonics) and decipher their relative impact and timing on sedimentary fluxes along continental margins.

Axis 4 activities will answer the following essential questions:

Can we quantify the Source of sediment produced through time?
What are the relative importance, through time, of tectonic, dynamic topography and palaeoclimate on the erosion processes? Can we decipher their relative role?
Another important question concerns transfer of sediment towards the deep domain during phases of erosion/transport/deposition.
Can we quantify the amount of sediment arriving in the Sink through time?
Can we estimate the vertical movements on the margins through time using sedimentary records?
Can we establish real Source to Sink budgets and model the role of the different parameters?
What is the role of tectonic heritage versus the location of sedimentary depocentres on the subsidence?

These questions are related to different time scales: from an event-scale (hours, days to weeks with possible direct measurements and instrumentation) to years, thousands years and million years for which internal earth processes (e.g. thinning of the crust) that govern subsidence plays a fundamental role in preservation of sediments and ought to be further understood.

Axis 4 will support and encourage the emergence of a common research group and initiative of collaboration with axis 3 and 5.

Expected results

Scientific objectives will contribute to a better knowledge of the dynamics of sedimentary transfers between the coast to the abyss domains, integrated over the entire sedimentary continuum, and their consequences at geological time-scale. This understanding needs a 4D characterization of sedimentary architecture and paleoenvironments from drainage basins and continental shelves towards the foot of the slopes with a land to sea approach using multiples proxies, but also through a modelling approach dealing with the complete system, which has not yet been achieved within the scientific community. Answering these questions will enable to better understand and better anticipate evolutions that have important consequences such as natural hazards (e.g. tsunamis, storms), coastal areas sensibilities (sea-level rise), climate change but also natural resources (gravels, hydrocarbons, economic zones) in many regions of the world.

More information (downloads)

2012-2015 axis4 roadmap

NEW : 2016-2019 axis 4 roadmap

Document Actions

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