Aurore Sibrant PhD - Postdoctoral researcher UMR6538 - Laboratoire Géosciences Océan Institut Universitaire Européen de la Mer Université de Bretagne Occidentale Technopôle Brest-Iroise, Place Nicolas Copernic Plouzané 29280, France Email: aurore.sibrant@u-psud.fr http://www.researchgate.net/profile/Aurore_Sibrant http://scholar.google.fr/citations?user=_H0GYVgAAAAJ&hl=fr

Postdoctoral project (2017-2019): The influence of plume-ridge interactions on the formation, evolution and rupture of oceanic plateaus: Improving constraints on the global magmatic budget. Geoscience Ocean Laboratory at university of Bretagne Occidentale, France. Supervisor: Marcia Maia. LabexMER.

Postdoctoral project (2015-2017): emplacement of regularly spaced volcanic centers in the East African Rift: Melt production or melt extraction? Geological Sciences department at university of Idaho, USA. Supervisor: Eric Mittelstaedt. NSF, Grant EAR-1456664.

Postdoctoral project (2014-2015): Impact of mantle plume below oceanic and continental lithosphere roots: implication of plate motion and volcanism expression over time. FAST laboratory at university of Paris-Sud, France. Supervisor: Anne Davaille. ANR RHUM-RUM.

PhD project (2011-2014): Evolution of the Graciosa, S. Miguel and Santa Maria volcanic islands: implications for the NU/EU plate boundary in the Azores. GEOPS laboratory at university of Paris-Sud, France. Supervisors: Anthony Hildenbrand and Fernando Ornelas Marques.

 

RESEARCH ACTIVITIES - TEACHING - EDUCATION

Research interests:

1. How do listhospheric and asthenospheric processes control the development of volcanism near triple junctions?
2. How ultra-slow spreading rifts evolved in space in time?
3. How do local and regional tectonic stresses control volcanic construction and destabilisation processes in areas of active deformation such as the Terceira Rift?
4. Can secondary mantle plumes under the lithosphere produce a cluster of hotspots? What is the spacing and time-dependence (birth, life, death and recurrence time) of these secondary plumes?
5. How mantle plume interaction with the lithosphere topography?
6. What is the contribution of melt production and melt extraction processes on the distribution of volcanic activity along the East African Rift System?
7. How does axial mechanical strength of the lithosphere affect ocean ridge segmentation?

Methods-Approaches:

• Geomorphological analyses from high-resolution DEMs
• Fieldwork, including observation, sampling rock, measurements of tectonic markers
• Geochronology (K-Ar unspike method)
• Geochemistry (flame photometry and LA-ICP-MS)
• Analogue modelling (fluid dynamics)
• Newtonian and non newtonian fluid rheology
• Indentation testing
• Refractometer
• Numerical modelling

PhD Committee ( Nov 3rd, 2014):

• Rapporteurs:
• Valerio Acocella, Permanent Researcher (Universita Roma Tre, Italy)
• Mathilde Cannat, Directrice de Recherche CNRS (Institut de Physique du Globe de Paris)
• Examinateurs:
• Andrew Calvert, Permanent Researcher (US Geological Survey, USA)
• Hermann Zeyen, Professeur HDR (Université Paris-Sud)
• Invités:
• Anne Davaille, Directrice de Recherche CNRS (Université Paris-Sud)
• Pierre-Yves Gillot, Professeur HDR (Université Paris-Sud)

Publications:

1. Sibrant, A.L.R., Mittelstaedt, E., Davaille, A., Pauchard, L., Aubertin, A., Auffray, L., Pidoux, R., 2018. Accretion mode of oceanic ridges governed by axial mechanical strength. Nature Geoscience 11, 274-279, doi:10.1038/s41561-018-0084-x.
2. Sibrant, A.L.R., Pauchard, L., 2017. Effect of the particle interactions on the structuration and mechanical strength of particulate materials. Europhysics Letters 116, doi:10.1209/0295-5075/116/49002.
3. Sibrant, A.L.R., Marques, F.O., Hildenbrand, A., Boulesteix, T., Costa, A.C.G., Catalão, J., 2016. Deformation in a hyper-slow oceanic rift: insights from the tectonics of the S. Miguel Island (Terceira Rift, Azores). Tectonics 35, issue 2, 425-446.
4. Sibrant, A.L.R., Marques, F.O., Hildenbrand, A., 2015. Reply to the comment by Quartau et al. on "Construction and destruction of a volcanic island developed inside an oceanic rift: Graciosa Island, Terceira Rift, Azores", J. Volcanol. Geotherm. Res. 284, 32-45, by Sibrant et al., (2014). J. Volcanol. Geotherm. Res. 303, 193-198.
5. Costa, A.C.G., Hildenbrand, A., Marques, F.O., Sibrant, A.L.R., Santos de Campose, A., 2015. Catastrophic flank collapses and slumping in Pico Island during the last 130 kyr (Pico-Faial ridge, Azores Triple Junction). JVGR 302, 33-46.
6. Sibrant, A.L.R., Hildenbrand, A., Marques, F.O., Weiss, B., Boulesteix, T., Hübscher, C., Lüdmann, T., Costa, A.C.G., Catalão, J., 2015. Morpho-structural evolution of a volcanic island developed inside an active oceanic rift: S. Miguel Island (Terceira Rift, Azores). J. Volcanol. Geotherm. Res., 301, 90-106.
7. Sibrant, A.L.R., Hildenbrand, A., Marques, F.O., Costa, A.C.G., 2015. Volcano-tectonic evolution of the Santa Maria Island (Azores): implications for palaeostress evolution at the estern Eurasia-Nubia plate boundary in J. Volcanol. Geotherm. Res., 291, 49-62.
8. Sibrant, A.L.R., Marques, F.O., Hildenbrand, A., 2014. Construction and destruction of a volcanic island developed inside an oceanic rift: Graciosa Island, Terceira Rift, Azores. J. Volcanol. Geotherm. Res., 284, 32-45.
9. Costa, A.C.G., Marques, F.O., Hildenbrand, A., Sibrant, A.L.R., Catita, C.M.S., 2014. Large-scale catatastrophic flank collapses in a steep volcanic ridge: The Pico-Faial Ridge, Azores Triple Junction. J. Volcanol. Geotherm. Res., 272, 111-125.
10. Hildenbrand, A., Marques, F.O., Costa, A.C.G., Sibrant, A.L.R., Silva, P.M.F., Henry, B., Miranda, J.M., Madureira, P., 2013. Reply to the comment by Quartau and Mitchell on Reconstructing the architectural evolution of volcanic islands from combined K/Ar, morphologic, tectonic and magnetic data: the Faial Island example (Azores). J. Volcanol. Geotherm. Res., 241-242, 39-48, by Hildenbrand et al. (2012). J. Volcanol. Geotherm. Res., 255, 127-130.
11. Hildenbrand, A., Marques, F.O., Costa, A.C.G., Sibrant, A.L.R., Silva, P.M.F., Henry, B., Miranda, J.M., Madureira, P., 2012. Reconstructing the architectural evolution of volcanic islands from combined K/Ar, morphologic, tectonic and magnetic data: the Faial Island example (Azores). Journal of Volcanology and Geothermal Research, 241-242, 39-48.

Conferences and Workshops:

• AGU, 2017, New Orleans, USA
  A.L.R. Sibrant, E. Mittelstaedt, A. Davaille
  Controls on mid-ocean ridge segmentation and transform fault formation from laboratory experiments using fluids of complex rheology.
• AGU, 2017, New Orleans, USA
  A. Davaille, S.E. Smrekar,A.L.R. Sibrant, E. Mittelstaedt
  Plume-induced subduction and accretion on present-day Venus and Archean Earth.
• AGU, 2017, New Orleans, USA
  J.P. Montagner, S. Maurya,A.L.R. Sibrant, A. Davaille, E. Stutzmann, R. Kumar, J. Besse
  Anisotropic tomography of the Indian contient and the geodynamic role of its keel.
• NetherMod, 2017, Putten, Netherlands
  A.L.R. Sibrant, E. Mittelstaedt, A. Davaille, L. Pauchard, A. Aubertin, L.Auffray, R. Pidoux
  Role of axial mechanical strength of the lithosphere on the accretion mode of mid-ocean ridges.
• NetherMod, 2017, Putten, Netherlands
  A. Davaille, S.E. Smrekar,A.L.R. Sibrant, E. Mittelstaedt
  Plume-induced subduction and accretion on convectiong planets: experiments and scaling relationships.
• IAVCEI, 2017, Portland, USA
  A. Hildenbrand, F.O. Marques, A.L.R. Sibrant, A.C.G. Costa, C. Huebscher, B. Weiss
  Tectonic control on volcano growth and large landslides near the Azores Triple Junction.
• EGU, 2017, Vienne, Autriche
  A. Davaille,A.L.R. Sibrant, E. Mittelstaedt, A. Aubertin, L.Auffray, R. Pidoux
  Exploring the morphology of oceanic ridges with experiments using colloidal dispersions.
• CREEP workshop, 2017, Rome, France
  A.L.R. Sibrant, A. Davaille, E. Mittelstaedt, A. Aubertin, L.Auffray, R. Pidoux
  Poster: Morphology of oceanic ridges in spreading colloidal suspensions.
• AGU, 2016, San Francisco, USA
  A.L.R. Sibrant, A. Davaille, E. Mittelstaedt
  Morphology of oceanic ridges in spreading colloidal suspensions: Influence of spreading rate and lithospheric thickness.
• AGU, 2016, San Francisco, USA
  L. Pauchard, A.L.R. Sibrant
  Effect of the particule interactions on the structuration and mechanical strength of particulate materials.
• CMG (Conference on Mathematical Geophysics), 2016, Paris, France
  A.L.R. Sibrant, L. Pauchard
  Mechanical measurements reflect the structure of a particulate material.
• CREEP workshop, 2016, Sete, France
  A.L.R. Sibrant, A. Davaille
  Poster: Continental lithospheric roots and plume-continent interaction: Implication for India motions over the last 130 Ma.
• AGU, 2015, San Francisco, USA
  A.L.R. Sibrant, A. Davaille
  Poster: On the importance of continental lithospheric roots in plume-continent interaction: implication for India motions over the last 130 Ma.
• AGU, 2015, San Francisco, USA
  L. Pauchard, A.L.R. Sibrant
  Poster: Crack patterns in layers: effect of the thickness and mechanical proprieties of the layer.
• WMESS, 2015, Prague, Czech Republic
  A.L.R. Sibrant, A. Hildenbrand, F.O. Marques, B. Weiss, T. Boulesteix, C. Hübscher, T. Lüdmann, A.C.G. Costa, J.C. Catalão
  Large-sector collapses in S. Miguel Island, Azores.
• WMESS, 2015, Prague, Czech Republic
  A. Hildenbrand, A.L.R. Sibrant, F.O. Marques
  Repeated large landslides during the evolution of Graciosa Island (Terceira Rift, Azores).
• WMESS, 2015, Prague, Czech Republic
  F.O. Marques, A.L.R. Sibrant, A. Hildenbrand, A.C.G., Costa
  Large-sector collapses in the evolution of Santa Maria Island, Azores.
• WMESS, 2015, Prague, Czech Republic
  A.C.G. Costa, A. Hildenbrand, F.O. Marques, A.L.R. Sibrant, A. Santos de Campos
  Evolution of the active slump on Pico Island's SE flank in the last 125 kyrs (Pico Island, Azores Triple Junction).
• RHUM-RUM workshop, 2015, Paris, France
  A.L.R. Sibrant, A. Davaille
  Oral presentation: Interaction between Reunion plume and India plate.
• AGU, 2014, San Francisco, USA
  A.L.R. Sibrant, A. Davaille, F.O. Marques, A. Hildenbrand
  Poster: Evolution of the central Atlantic hot spots cluster in the last 100 Myr: interaction between plate tectonics, a lower mantle thermochemical instability and upper mantle secondary plumes.
• Goldschmidt, 2014, Sacremento, USA
  M.A., Al Kwatli, P.Y., Gillot, J.C., Lefèbre, A., Hildenbrand, A.L.R. Sibrant
  Talk: Dynamic melting of heterogeneous mantle sources beneath the northern part of the Arabia: Geochemical modelling and geodynamic contraints.
• AGU, 2013, San Francisco, USA
  A.L.R. Sibrant, A. Hildenbrand, F.O. Marques, A.C.G. Costa
  Poster: Volcano-tectonic evolution of Santa Maria Island: implications for Nubia-Eurasia plate boundary in the Azores. Awarding by the OSPA.
• AGU, 2013, San Francisco, USA
  F.O. Marques, A.L.R. Sibrant, A. Hildenbrand, A.C.G. Costa
  Poster: Large-scale sector collapses in the evolution of Santa Maria Island, Azores.
• AGU, 2013, San Francisco, USA
  A.C.G. Costa, F.O. Marques, A. Hildenbrand, A.L.R. Sibrant, C.M.S. Catita
  Poster: Large-sacale mass wasting in a small but steep volcanic ridge: the Pico-Faial Ridge in the Azores Triple Junction.
• 8th IAG, International conference on Geomorphology, 2013, Paris, France
  A.L.R. Sibrant, A. Hildenbrand, F.O. Marques, T. Boulesteix, A.C.G. Costa
  Talk: Morpho-structural evolution of a volcanic island developed inside an active oceanic rift: Sao Miguel Island (Terceira Rift, Azores)
• 8th IAG, International conference on Geomorphology, 2013, Paris, France
  A.C.G. Costa, A. Hildenbrand, F.O. Marques, A.L.R. Sibrant, J. Catalao, C.M.S. Catita
  Talk: Tectonic and Morphologic evolution of an active large-scale slump (Pico Island, Azores)
• Final Crystal2Plate Workshop, 2013 , Frejus, France
  A.L.R. Sibrant, A. Hildenbrand, F.O. Marques, A. Davaille
  Poster: Rifting and volcanism close to triple junctions: interactions between lithosphere break-up and mantle dynamics in an active oceanic rift.
• IGC, International Geological Congress, 2012, Brisbane, Australia
  F.O. Marques, A. Hildenbrand, J.C. Fernandes, C.M. Catita, A.C. Costa, A. Sibrant.
  Poster: Active creep in large-scale slump on Pico Island (Azores)
• EGU, 2012, Vienna, Austria
  A. Hildenbrand, F.O. Marques, A.C.G. Costa, A.L.R. Sibrant, P.F. Silva, B. Henry, J.M. Miranda, P. Madureira
  Talk: Reconstructing the architectural evolution of volcanic islands from combined K/Ar, morphologic, tectonic, and magnetic data: the Faial Island example (Azores).
• AGU, 2011, San Francisco, USA
  F.O. Marques, A. Hildenbrand, J.C. Fernandes, C.M. Catita, A.C. Costa, A. Sibrant.
  Poster: Active large sector collapse and architectural evolution of the Pico Island (Azores).
• Congresso Jovens Investigadores em Geociencias, 2011, Evora, Portugal
  A.C.G. Costa, F.O. Marques, A. Hildenbrand, A.L.R. Sibrant
  Talk: Estratigrafia vulcanica na Ribeira de Pedro Miguel - implicacoes na evolucao do Graben do Faial - Azores.

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TEACHING:

• 2013
  • L3 Geology, fieldwork, internal dynamic of the Earth: the volcanoes (Cantal, France)
  • M1 Geology, lesson, main minerals and rocks
  • M1 Geology, TD/TP volcanic rocks
• 2012
  • L2 Biology, lesson, Magmatism and magmatic rocks, Volcanism and eruption, Metamorphism and metamorphic rocks, initiation of cartography, TD/TP, cartography, minerals and rocks
  • L3 Geology, TP, Geochemistry
  • L3 Geology, fieldwork, internal dynamic of the Earth: the volcanoes (Cantal, France)
  • M1 Geology, lesson, main minerals and rocks, TP, K-Ar dating
  • M2 Volcanic environment, fieldwork, Auvergne Volcanism (Chaine des Puys, Mont Dore, Cezallier, Cantal) France
    
• 2011
  • L1 biology, TD/TP density and gravity, volcanic metamorphic and sedimentary rocks, geochronology, hydrology and risk and landslide
  • L1 physics, TD, composition and structure of the Earth, seismic, tectonics plates, isostasy and water cycle
  • L2 Biology, TD/TP, cartography, minerals and rocks
  • M1 Geology, lesson on Azores volcanism, TD, density-viscosity, teledetection and tephra dispersion, volume and caldeira

EDUCATION: PhD,CNU qualification in section 35 and 36.

• Sept 2017 - August 2019: Postdoctoral researcher in the Geocience Ocean laboratory at University of Bretagne Occidentale, France
• July 2015 - June 2017: Postdoctoral researcher in the Departement of Geological Sciences at University of Idaho, USA
• Nov 2014 - June 2015: Post-Doc position in the FAST laboratory at Paris-Sud, France
• Oct 2011 - Nov 2014: PhD student in Earth Science at Paris-Sud, France
• 2009- 2011: Master In Earth Science, sedimentary and volcanic environment at Paris Sud, France
• 2009: Licence in Biology at Le Havre University, France

 

 

Research interests:

1. How do listhospheric and asthenospheric processes control the development of volcanism near triple junctions

Active rifts are inferred to grow and evolve as a reponse to asthenospheric mantle upwelling, whereas passive rifts develop as a response to lithosphere extension due to far field stresses. At triple junctions, both types of rifts can co-exist and interact in a complex way, producing a number of geological features like oceanic plateaus, tectonic structures and widespread volcanism. An analogue fluid dynamic approach is being used to model mantle and lithosphere interactions and test whether the TR and volcanism could have initiated and developed in response to a buoyant mantle plume.

Experimental modelling performed at the FAST laboratory

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2. How ultra-slow spreading rifts evolved in space in time?

This part of my PhD thesis aims to investigate the spatial and temporal evolution of the Terceira Rift by K-Ar ages analyses. The Terceira Rift (TR) is an ultraslow spreading axis, which materialized the plate boundary between Eurasia and Nubia plate. The TR consists of alternance of islands and seamount, each separated by deep amagmatic basins. Is there any spatial or temporal evolution of island along the Terceira Rift

Gravity map of the Azores Archipelago. MAR: Mid Atlantic Ridge; EAFZ: East Azores Fracture Zone; TR: Terceira Rift; Cor: Corvo; Flo: Flores; Gra: Graciosa; Fai: Faial; SJO: S. Jorge; Pic: Pico; Ter: Terceira; SMI: S. Miguel; SMa: Santa Maria

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3. How do local and regional tectonic stresses control volcanic construction and destabilisation processes in areas of active deformation such as the Terceira Rift?

The morpho-structural evolution of oceanic islands results from competition between volcano growth and partial destruction. This destruction can be gradual (slump) or instantaneous as vertical caldeira, major flank collapses. Because the Azores are characterized by intense deformation, the island are particularly sensitive to mass-wasting processes. We combine tectonic analysis, K-Ar dating and morphological analysis to study the competition between volcanic construction and destruction by tectonic processes.

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4. Can secondary mantle plumes under the lithosphere produce a cluster of hotspots? What is the spacing and time-dependence (birth, life, death and recurrence time) of these secondary plumes?

Theories and models of thermal convection in the mantle of the Earth suggest the existence of plumes of hot material that may rise from deep levels. These lower mantle superplume can be blocked in the transition zone and crowned by several small-scale upper mantle secondary plumes that give rise to hotspot tracks observed on the surface. In the central Atlantic, it may explain the hotspots cluster constituted by Azores, Canary, Cape Verde, Great Meteor and Madeira. Therefore, we investigate the spacing, the time dependence (birth, life, death and recurrence time) of these secondary plumes in the Northern Atlantic ocean.

Tomographic map of the central Atlantic. Red and black circle indicate active and inactive volcanism.

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5. How does mantle plume interact with the lithosphere topography?

Oceanic plateaus close to Triple Junction (TJ) and associated plate boundary migrations have rarely been examined in details; in part because they are extended, remote from land, and covered with thick sediments and therefore bathymetric or geochronological data are lacking. The Azores system is an ideal location to study the migration of TJ in response to oceanic plateau and hotspot due to the well-known regional tectonic and volcanic sub-aerial history. What is the role of the abnormal mantle under a basaltic plateau and abnormal lithospheric structure?

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6. What is the contribution of melt production and melt extraction processes on the distribution of volcanic activity along the East African Rift System?

The primary goal of my second postdoctoral proposal is to use data from coupled numerical and laboratory experiments along with observations from the East African Rift System to quantitatively assess the contribution of both melt production and extraction processes on the distribution of volcanic activity. We use two groups of coupled laboratory and numerical experiments; the first simulate lithospheric extension with variable spreading rate and lithospheric thickness. We use a non-Newtonian viscous fluid with brittle behavior. Numerically, we use a 2D marker-in-cell, finite difference code to initially match the laboratory experiments and then expand the parameter range beyond that possible in the laboratory. We simulate Rayleigh-Taylor instabilities within the partially molten mantle (melt production) and the importance of pre existing fractures (melt extraction).

An example of Rayleigh-Taylor instability. The lower, less dense fluid is inherently an order of magnitude less viscous than the upper, more dense fluid. The simulation is run using HiPStER on 333*100 grid nodes with 25 markers/cells.

 

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7. How does axial mechanical strength of the lithosphere affect ocean ridge segmentation?

Rheologic and tectonic controls on oceanic segmentation from laboratory models. Using a colloidal flui, Ludox, in laboratory models of seafloor spreading, we examine visco-elastic-plastic deformation and faulting at a simulated ridge axis. By separately varying the rate of spreading and the growth rate of the thickness of the simulated tectonic plates, we examine how plate strendth control the oceanic segmentation. This project is in collaboration with E. Mittelstaedt at the U. of Idaho and A. Davaille at the U. Paris-Sud.

	Mid-oceanic ridges in the laboratory. Ridge axis morphology observed in the experiments for a salt concentration of 4.28 mol/l at different spreading rates.

 

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