ISTO is a research institute covering a broad thematic spectrum with particularly wide scales of space (from mountain ranges to nanometric interfaces), time (minutes to millions of years) and particularly wide P-T ranges (-2 to +40 kbars; -40°C to 2000°C). The preferred study topics concern the biogeochemistry of the the critical zone and the water-soil-plant-atmosphere continuum, reactive transport in saturated and unsaturated porous media, chemo-mechanical couplings, metallogeny and enrichment enrichment processes, thermodynamics and physics of silicate liquids and degassing processes, crustal rheology and localization of deformation on a geodynamic scale.

Five research groups structure our scientific fields: Magma, Geodynamics, Metallogeny and geo-energy, Porous media, Continental biogeosystems. The The first three are in the orbit of section 18, while the fifth depends on section 30; Porous Media offers themes shared between the two sections, 18 and 30. Metallogeny, Porous and Biogeosystems are at the heart of the collaboration strategy with BRGM, and the last two are strongly linked to the scientific priorities of the Centre region.

On all these subjects, ISTO develops in situ observations and measurements, in the laboratory or in the field. In the laboratory, the in situ character means reproducing T-P-X conditions of the natural environment on constrained samples (geometry, composition, etc.), and/or acquiring very localised measurements, typically of composition, to trace physical or chemical processes and mechanisms. In the field, the in situ character translates into high-resolution and high-throughput measurements, associated with advanced spatialization techniques, to promote better representativeness of the data used as a basis for conceptual models. The instrumental character continues to be strengthened through major investments (Labex VOLTAIRE, Equipex PLANEX, CPER-FEDER project PIVOTS: metrology, sensors ; PLAT’INN: ecotechnologies; MIMAROC: thermomechanics of rocks; PROMESTOCK; RADIOCENTRE).

The scientific unity is ensured by the convergences allowed by the experimental methodologies but also with the numerical, mechanistic-diagnostic and geostatistical-predictive modelling. predictive geostatistics. Joint multi-scale/multi-physics modelling and simulation activities should bridge the gap between the different spatial and temporal scales and also couple with the and temporal scales and also to couple the different classes of mechanisms involved in the phenomena studied. This component is crucial for This component is crucial for developing applications and services, particularly in environmental engineering, and several regional public (BRGM, IRSTEA, INRA) or private (ANTEA) partners are contributing to this.

This identity based on experimentation, both laboratory and field, in deep and surface geology, is the foundation of the unit.

ISTO presentation sheet

ISTO in a few figures

10M€ of equipment

  • a national HP-HT platform (transparent autoclaves with optical spectrometry and X-ray imaging/diffractometry) and X-ray diffractometry) and deformation (Griggs press, Paterson press)
  • the largest European platform for rare gas analysis analysis (Ar-Ar, K-Ar, isotopy)
  • a reference centre for multi-sample organic analysis
  • a micro/nano-fluidic platform coupled in spectrometry and optical microscopy

100 projects over 2016-2021 :

48 CNRS projects, 25 Région Centre, 12 ANR, 5 Europe projects, 4 FEDER, 2 CPER, 2 industrial projects, 2 ERC

6 investments for the future :

1 Labex, 2 Equipex, 1 Equipex+, 1 IDEFI, 1 GIS

32 engineers, technicians, administrative staff
50 PhD students and post-docs
46 researchers and lecturers
10 thesis/year over 2016-2021
108 articles/year over 2016-2021
22 years of experience

Steering the institute

The Director of the Unit (DU) and his deputies are appointed jointly by all the supervisory bodies, after the opinion of their statutory bodies and the and the laboratory council. Two deputy DUs assist the Director in his missions. The Administrative Manager (AR) provides advice and follow-up on regulatory, administrative and budgetary aspects. administrative and budgetary aspects.

A short story of the institute

The Earth Sciences Institute of Orléans is a joint research unit (UMR), under three supervisory structures to date: the University of Orléans (UO), the CNRS and the BRGM. ISTO is attached to the Observatory of Sciences of the Universe in the Center Region (OSUC), a federative structure grouping three research units.

© Didier Depoorter
© Didier Depoorter

ISTO started in January 2000 grouping a CNRS unit (UPR 4201, Center for Research on Synthesis and Chemistry of Minerals) on experimental petrology, and two UMRs, on geodynamics (UMR 6530, Geotectonics, Geophysics and Metallogeny), and on organic matter (UMR 6531, Sedimentation and Diagenesis of Organic Matter). ISTO (UMR 6113) then appeared as a trans-disciplinary laboratory, at the time bringing together UO and CNRS, closely associating the objects and approaches of deep Earth and Environment.


During the 2008-2011 quadrennial, a Touraine team from surface geology (GéHAC, now GéHCO) joined the structure, which combined the supervision of two universities and the CNRS. In 2008, the department of Loiret and the Center region completed the construction of a university building (2225 m²) adjoining the CNRS historical building (1808 m²). This real estate operation allowed the very structuring localization on the same site, of the Orleans research staff with the geological students. This everyday proximity is a discrete but powerful lever of the education-research continuum, founding the university education.

In the following contract (2012-2017), efforts focused on this proximity logics, with the departure of the Tours team and the arrival of the BRGM as a secondary supervision body (UMR 7327). 2012 also saw the creation of the Universe Science Observatory in the Center Region (OSUC), associating ISTO with the LPC2E (UMR 7328, UO-CNRS) and the Nançay Radio Astronomy Station (UMS Observatoire Paris-CNRS-UO). OSUC is also a full-service component of UO, namely responsible for the Earth Sciences Master’s degree, which is taught by the ISTO faculty and researchers.


Excellent synergies were created during these years, which allowed ISTO to lead two major successful projects at Investissements d’Avenir (IA): the LabEx VOLTAIRE (2011-2019), dealing with the transfer and reactivity of fluids and from the deep crust to the atmosphere, and the EquipEx PLANEX (2012-2019), a platform for in situ spectroscopy at high pressure and temperature. The institute also participated in the successful consortium of one IA-IEED (institute for excellence for low-carbon energies), which has since become a group of scientific interest (GIS), GEODENERGIES (2015-2020), led by BRGM, on the use of the subsoil for the energy transition. ISTO was also especially instrumental in the IA-IDEFI (institute for excellence in education) EDIFICE (2012-2019), led by UO, to fund innovative pedagogical approaches on the high school-university continuum. A new call Equipex+ related to the third stage of IA program offered ISTO to participate in a project IMAGINE2 (correlative imaging for the energy and environmental transitions) funded in 2021 for 8 years. At the regional scale, ISTO has also actively participated in setting up the PIVOTS program, led by BRGM, which was funded by the Region Centre as part of its Ambition Research Development 2020 program. This project (2015-2021) is devoted to environmental monitoring and development. ISTO is particularly leading two of the six platforms, one dealing with the deep unsaturated zone and the other with the ground-atmosphere interface. It continues with the JUNON project (2021-2025).

Today, the common scientific strategy between the Institute’s three supervisory authorities is steadily growing and is leading ISTO towards a new contract in the same configuration.

© Emma Raffard
© Emma Raffard