3 Works

Crystallisation sequence of a REE-rich carbonate melt: an experimental approach

Valentin Mollé , Fabrice Gaillard, Zineb Nabyl , Johann Tuduri , Ida Di Carlo & Saskia Erdmann
Carbonatites host the main REE deposits in the world, with bastnaesite being the main REE-bearing mineral of interest. However, the nature of the enrichment process, magmatic vs hydrothermal, is still debated. This study aims to experimentally determine the behaviour of REE elements during carbonatite crystallisation, and if bastnaesite can be directly crystallised from a carbonate melt. Crystallisation experiments have been done from 900 to 600°C at 1 kbar on a REE-rich calciocarbonatitic composition. Calcite (Ca,REE)CO3...

The permeability of granite deformed in the brittle regime to large strains: Implications for the permeability of fractured geothermal reservoirs

Michael Heap , Hugo Duwiquet , Luke Griffiths , Laurent Guillou-Frottier , Patrick Baud & Marie Violay
Efficient fluid flow and circulation are important for an economically viable geothermal reservoir. One type of underexplored reservoir for high-temperature geothermal exploitation is a crustal fault zone, where hot fluids from depths corresponding to the brittle-ductile transition are brought to the surface via crustal-scale, permeable fault zones. To better understand the evolving permeability of reservoir rock during deformation in the brittle regime—fault formation and sliding on the fault—we performed triaxial experiments on samples of well-characterised...

Trace element partitioning between apatite and carbonatite melt at 800 °C and 200 MPa

Haihao Guo , Fabrice Gaillard & Zineb Nabyl
Apatite is a pivotal mineral in carbonate rocks, because it can incorporate all of the major magmatic volatile species (H, P, F, S, Cl), as well as REE and HFSE into its structure. To quantify the effects of fractional crystallization of apatite crystals on the (H, P, F, S, Cl) volatiles and metal budget in the residue melt, the partition coefficients of a broad range of elements (F, Cl, S, REE, HFSE, Co, Ni, Sr,...

Registration Year

  • 2022

Resource Types

  • Text


  • University of Orléans
  • Bureau de Recherches Géologiques et Minières
  • University of Strasbourg
  • École Polytechnique Fédérale de Lausanne
  • Norwegian Geotechnical Institute
  • Institut Universitaire de France