PHD THESIS POSITIONS

PHD THESIS POSITIONS

Call for a doctoral position in The Ni biogeochemical cycle in a tropical agromine metal crop system:

consequences of the exhaustion of available soil Ni pool due to sustained harvesting” The research on nickel isotope geochemistry in ultramafic ecosystems undertaken by Nicolas Estrade (post-doctoral research funded by LabEx R21) unambiguously demonstrated that plants, specifically hyperaccumulator plants, directly influence the composition of available and total Ni pools in ultramafic soils. The results of this work generated the following hypothesis: plants, and particularly Ni hyperaccumulator plants, play a major role in maintaining high concentrations of Ni in the surface of soils during weathering and pedogenesis. Hence, agromining ultramafic soils will necessarily deplete the plant generated Ni-reservoir. More

 

Call for a doctoral position in Mobility and transfer of rare earth elements from soil to plants by arbuscular mycorrhizal fungi

The objectives of the pH-D thesis will be to precise the toxicity of rare earth elements (REE) towards root symbiotic fungi and to study the role of  these fungi in the transfer of REE to plants. The hypothesis is that arbuscular mycorrhizal fungi play a role of filter towards toxic metallic elements  (Redon et a. 2008). Binding of REE at the hyphae level, as previously observed for metallic trace elements such as Cd, could contribute to a better fitness of plants in the presence of high concentrations of REEs. Arbuscular mycorrhizal fungi might then be considered to inoculate the plants used for phytomanagement of REE contaminated soils. More

 

Call for a doctoral position in mining operations "Project risks". Evaluation and commensuration of technical and societal risks, with application to open pit mines during the development and exploitation phases, especially under tropical climate.

The considerable development of the mining industry over the last years is characterized by an explosion of demand and therefore production of most metals. To face them, most of the mining companies have started to look for high-tonnage, low-grade ores. Consequently, they are faced with higher technical challenges: the need to avoid, to reduce or to compensate environmental impacts (impact on soil and water quality, noise pollution and dust, rehabilitation, etc.), the management of geotechnical risks (instability of pit walls and stock piles, etc.) and the management of large volumes of sterile, in a context where the safety requirement Increases. More

 

Call for a doctoral position in Magmato-hydrothermal transport and deposit of W(Sn, Nb (Ta) in magmatic-metamorphic fluids around plutons.

Transport and deposition of W (Sn, Nb (Ta) ores from in magmatic-metamorphic fluids around plutons (Filled)

PhD thesis within the framework of the European projet ERAMIN “NewOres” and Labex “RESSOURCES21”

The objective of the study of the magmatic-hydrothermal transition is of primary importance to understand the current mineralogical expression of the rare metal ore deposits and to discriminate the strictly magmatic processes (issued from partial melting, fractionated crystallization, assimilation, immiscibility) from the hydrothermal processes in which host formations (granites) could also have played a major role as source of metals. An important point is to determine if metals such as W-Nb-Ta-Li-Sn result from a same source or if several sources including non-magmatic ones are involved.

 

Call for a doctoral position in the Mineralization of Nickel in saprolitic ore of New Caledonia: Metal transfer dynamics and modeling of geochemical and hydrodynamical processes (Filled)

Starting in october 1, 2014

Context: Laterite nickel-ore formation in New Caledonia is classically assumed to be governed by supergene processes. However, this conceptual model fails to explain some recent mineralogical or structural observations. In particular, none of supergene models succeed to describe the heterogeneity of mineralizing distributions that could have been enhanced by several syntectonic pre-enrichment cycles. Actually, fluid flow and mass transfer processes are not purely downward at low temperature conditions, but can be also related to hydrothermal fluid circulations. More...