F1 : Earth as a living planet: from early ages to present dynamics
The description and understanding of the dynamics of the solid Earth, as well as its interactions with the hydrosphere and the biosphere, requires quantitative constraints on the processes at work. The theory of plate tectonics, the principles of geochemical dynamics applied to tracking of surface and deep Earth processes, as well as pioneers studies of bio-mineral interactions are examples of achievements obtained at IPGP during the last decades. However, as good as the understanding of present solid and surface Earth dynamics is, its initiation during the early ages of the Earth remains poorly constrained and understood. To fill the gap between the present and pristine dynamics of the Earth, specific sub-projects linked to the exploration of the proto-Earth and to the study of modern analogues will be developed conjointly. During the first two years of Frontier Project 1, effort will be devoted at 1) performing a new drilling operation of a key stratigraphic succession of the Archaen Eon and 2) constraining the rates and regimes of deformation over a range of spatial scales along the Chiliean Margin.
The Turee Creek Group Drilling Project (TCDP), Hamersley Basin, Western Australia
Project coordinators: P. Philippot (IPG Paris, France), M. Van Kranendonk (University of New South Wales, Australia) in coordination with the Geological Survey of Western Australia.
As part of the project Labex « UnivEarth » hosted at the Institut de Physique du Globe de Paris, we aim at obtaining three diamond drill core of rock samples of the Turee Creek Group, Western Australia, for scientific analysis. The principal aims of the project, to investigate vertical stratigraphic changes in mineral and rock geochemistry, organo-metallic assemblages, seawater precipitates, and changes in the composition of the Earth’s atmosphere between 2.45 and 2.21 Ga, should improve our understanding of the nature and timing of the “Great Oxidation Event”. Results from the project could also help to explain the global atmosphere-related changes in sedimentary mineralization that occurred during the Paleoproterozoic.
Figure 1 : Geological Map of Western Australia showing the drilling core site of Turee Creek
Reasons for drilling the Turee Creek Group:
The Turee Creek Group represents the uppermost section, out of three, of the Hamersley Basin, which was initiated by crustal extension at approximately 2.8 Ga and accumulated in excess of nine kilometers of sediment by 2.2 Ga. Of interest for the present study is that stromatolite platform carbonate rocks are present throughout the basin, starting with 2.72 Ga old Tumbiana Fm. (PDP1 drill core obtained in 2004 by our group) and culmunating with the 2.4 to 2.2 Ga old Kazput Fm. of the Turee Creek Group. The Turee Creek has a total thickness of about 3 km, shallowing upwards from banded iron formation (BIF) of the underlying Boolgeeda Iron Fm. forming the top of the Hamersley Group, to clastic sedimentary rocks, glacial diamictites of the Meteorite Bore Member and stromatolitic carbonates of the Kasput Formation. It is the only unit in the world that shows evidence for continuous deposition across the Great Oxidation Event. The Turee Creek Group thus provides a unique opportunity to examine the nature, rate, and duration of the rise of atmospheric oxygen on Earth.
Figure 2: Stratigraphic section of the Turee Creek Group. Potential drilling sites identified include the contact between the Boolgeeda and the Kungari Fromations, The Meteorite Bore Member diamictites and a section of the Kazput Formation.
In addition to drilling costs, FP-1 grant will support a 2 year post-doc. The position has been attributed to J. Marin-Carbonne. Her work is dedicated at developing in situ S, Fe and N isotope analysis on the same minerals. These analyses will be obtained in situ using the new ion probe installed in Nancy.
Active deformation and earthquake activity along the Andean subduction zone in Chile
Coordinators: R. Armijo (IPG Paris, France), R. Lacassin (IPG Paris), N. Shapiro (IPG Paris), J.P. Vilotte (IPG Paris)
International collaborations: Universidad de Chile (J. Campos and G. Vargas), Universidad Católica del Norte (G. Gonzalez), GeoForschungsZentrum (GFZ) Potsdam (O. Oncken), University Potsdam (M. Strecker)
The Andean subduction zone in Chile, associated with the fast convergence of the Nazca plate beneath the South American plate, is one of the most active in the world as attested by the Andes, the largest mountain belt – and high plateau – systems of our living planet, and by the associated seismic activity with four mega earthquakes and tsunamis in the last 120 years. Scientific questions today are related to the understanding of the transient and permanent deformation processes, their variations and interactions, along the Chilean subduction zone, that lead to the occurrence of large subduction earthquakes and tsunamis, and to the building of the Andes. A critical step, of important augmented economic and societal implications, is to integrate these different spatial and temporal scales within a geodynamic model.
The Andean subduction zone in Chile and the associated large subduction earthquakes: the earthquakes rupture area is indicated by the size of the ellipses; and the mean rate and direction of the convergence between the Nazca and the South American plate is indicated by the arrow. The main barriers associated to the segmentation the subduction zone are pointed in this map
To address these questions, innovative data analysis and data modelling methods are required to exploit the massive data generated by the detailed tectonic and paleo-seismology field studies, the high-resolution observation systems integrating geodesy and seismology monitoring networks operated by the International Associated Laboratory Montessus de Ballore (https://www.lia-mb.net), the French-Chilean initiative between the CNRS-INSU and the Universidad de Chile (Santiago), in which IPGP is one of the main partners, and by the spatial observation systems (InSAR).
The first objectives are :
- Detailed analysis of the February 27, 2010 offshore Maule (Mw 8.6, Central Chile) earthquake, in terms of the rupture process, associated crustal deformation and crustal property changes, of its implication in term of the seismic hazard in the northern part of Central Chile - in particular the Valparaiso region. This analysis will exploit the extensive seismological (at regional and global scales), geodetic and geological data that are today available with unprecedented accuracy, before, during and after the event. Lessons to be learned from the offshore Maule earthquake will have important implication and applications for further study of the seismic hazard in northern Chile.
- Study of the permanent deformation, associated to the growth of the Andean orogeny by tectonic shortening, measured over the 103-107 yr time scale, which is barely longer than the seismic cycle for subduction earthquakes. We want to characterise the evolution of the west-vergent geological structures in relation with the subduction processes and to construct a mechanical model involving tectonic accretion at the subduction interface consistent with the tectonic and morphological evolution of the Central Andes and the Altiplano. This will imply new field observations that will be collected during this project.
This project is supporting a 1-year postdoc, attributed to Natalia Poiata, and a number of tectonic field studies, sampling and dating.
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Magali Ader |
Carbon, Oxygen, Azote, stable isotopes studies to calibrate the isotopiques signatures on modern sedimentary rocks as a proxy of ancient sediments Identification of diagenetic phases that have altered paleo-environmental signatures Reconstitution of Precambrian paleo-environment and paleo-ecosystem |
IPGP
Bureau 513
+33 1 83 95 75 06
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Jean Besse |
Internal and external dynamic reconstitution with paleo-magnetique tools Ancient Gedoynamo; Intensity and Inversion of terrestrial magnetic field Plate tectonic Large drift of Earth axis as indication of mantle convection |
IPGP Bureau 136 +33 1 83 95 74 87 |
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Vincent Busigny |
Fe, C and N stable isotopes stables in ancient rocks in order to reconstruct the paleo environment and paleo-ecosystem conditions
Studies of aquatic anoxic and ferruginous system as Pavin lake (Massif Central) as a modern proxy of Archean ocean
Isotopic signatures of biogeochemical process from the water column to the sediment
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IPGP Bureau 515 +33 1 83 95 74 34 |
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Pierre Cartigny |
S (36S/32S, 33S/32S, 34S/32S) and O (17O/16O, 18O/16O) isotopic compositions analysis to reconstruct the paleo-environmental conditions and atmospheric composition of the Archean and Neoproterozoique |
IPGP
Bureau 511
+33 1 83 95 75 11
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Frédéric Fluteau |
Pre-Quaternary climatic changes studies with numerical modelling of climate, C biogeochemical cyce and continental weathering
Quantification of processes controlling Earth climate. Reconstitution of physical and chemical evolution of fluid reservoir of the Archean with 3D climate and geochemistry modelling |
IPGP
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Jérôme Gaillardet |
Identification of isotopic, mineralogical and geochemical signature of water and river sediments produced by interaction with sulfuric acid Interpretation of ancient sediment with important chemical weathering rate Possible isotopic proxy Mo, W, Cr exploration in Precambrian rocks |
IPGP
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Robin Lacassin |
IPGP
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Guillaume Le Hir |
Pre-Quaternary climatic changes studies with numerical modelling of climate, C biogeochemical cyce and continental weathering
Quantification of processes controlling Earth climate. Reconstitution of physical and chemical evolution of fluid reservoir of the Archean with 3D climate and geochemistry modelling |
IPGP
Bureau 130
+33 1 83 95 74 93
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Johanna Marin-Carbonne |
Metal stable isotope analysis to better understand the possible biological and redox signatures in ancient sediment Petrographical and mineralogical study of drillcore and in situ analyses of stable isotope |
IPGP
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Pascal Philippot |
Deep Biosphere and Origin of Life |
IPGP
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Natalia Poiata |
Analysis of seismicity in Chile: aftershock sequence of the 2010 Maule earthquake and seismicity in North Chile after the 2007 Tocopilla earthquake. Development of new array-based methods for detection and localization of seismic events. |
IPGP
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Nikolai Shapiro |
IPGP
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Mark Van Zuilen |
Structural, chemical and isotopic characterization of possible biological structure present in ancient rocks, microfossils in chemical sediments micro laminations in stromatolithes and minerals in hydrothermal environment Characterization of life signatures in archean rocks, structure of metamorphosed carbone by Raman spectroscopy and FIB-TEM In-situ analysis of isotopic and elemental compositions of organic material and associated minerals (δ13C, N/C- ratio, δ34S-Δ33S).
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IPGP
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Jean-Pierre Vilotte |
Mechanical and numerical modeling of earthquake rupture dynamics
Numerical simulation of wave propagation in complex geological systems
Coherent interferometry imaging of extended earthquake sources
Computational physics and parallel computing
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IPGP
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Seminar "Tracking oxidative weathering on the early Earth: Evolutionary and ecological implications"24 November 2014, 14:49
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20 September 2013, 11:58
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13 December 2012, 21:04
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11 June 2012, 14:58
