Thesis : Microstructures and thermobarometry study of the compressive deformation of the basement in the axial Pyrenean zone.
My PhD is part of the ITN project Zooming In between Plates (ZIP). The project focuses on subduction zones, where most of geohasards (earthquakes, volcanism, tsunami) occur. To better understand what happen in these area, it is important to study the processes inSvolved. In this project, my PhD research is focused on processes occurring at depth.
The main aim is to unravel the links between fluid circulation, rock deformation and rock composition at depth. To investigate these interactions I work in two different field areas : Tianshan (NW China) and Monviso (Alps), which both preserve parts of fossil subduction zones.
Tianshan is composed of rocks which underwent HP to UHP metamorphism, and were deformed at great depth (70-100 km), with an important fluid circulation. My work in this area consists in unraveling the geodynamical evolution of this metamorphic belt, as a good study case of a fossil plate interface. To achieve this, I estimate P-T conditions using mineral chemical data (microprobe) and Raman spectroscopy. This is combined with a structural study to constrain the deformation history.
At the same time, I study the Monviso area in order to investigate the timing of deformation to constrain the activation duration of shearing. This will be done by Li chronometry study.
Zhou Tan, Philippe Agard, Jun Gao, Timm John, JiLei Li, Tuo Jiang, Léa Bayet, XinShui Wang, Xi Zhang (2017) P–T–time-isotopic evolution of coesite-bearing eclogites: Implications for exhumation processes in SW Tianshan. Lithos 278-281, 1-25.
Lea Bayet, Lowen Moritz, Jilei Li, Tan Zhou, Philippe Agard, Timm John, and Jun Gao (2016): Insights into a fossil plate interface of an erosional subduction zone: a tectono-metamorphic study of the Tianshan metamorphic belt. EGU General Assembly conference, (Vienna, Austria). EGU2016-6811 Oral Presentation.