Scientists at the University of Lille 1 are Using the Linkam MDS600 Stage for Fluid Inclusion Studies

In the Laboratory of Civil Engineering and geo-Environment (LGCgE) of the University of Lille 1, Professor Michel Dubois and two of his MSc students, Mrs Hulin and Mrs Ventalon, have been using the Linkam MDS600 stage for fluid inclusion studies.

The LGCgE consists of three research areas: habitat, geo-materials and geo-environment. The geo-environment department investigates the impact humans have had on the environment, how natural resources are utilized, industrial activities past and present, and urban transport. This includes metal and organic pollution, the transfer processes of pollutants in soil and groundwater, and the impact of pollution on ecosystems. By investigating soil geochemistry, hydrodynamics, and ecological/biological studies, the researchers can advise decision makers to help them make informed decisions regarding reclamation of degraded areas, protection of the environment, and prevention of pollution in France.

Professor Dubois, whose works contributes to the geo-environment research, uses the Linkam MDS600 stage to look at small cavities within minerals which have trapped mixtures of water, salts and gases present in the earth interior. These cavities are known as fluid inclusions, and they are useful for the identification and understanding of ore deposition processes, petroleum reservoirs and the environment. He noted "The Linkam stage is a key piece of apparatus in the fluid inclusion laboratory. Its design makes it very convenient to study very small inclusions (less than 5 µm) as it is compatible with high magnification objectives (x100)."

Prof. Dubois added "geological fluids are important chemical vectors in the Earth, particularly for metals. By heating inclusions, the formation temperature can be deduced, whereas cooling allows the determination of the fluid composition. Temperature and chemical composition of the trapped fluids is fundamental information for scientists creating ore deposition models and new guidelines for exploration."

The MDS600 is a motorized version of the THMS600, one of the most widely used heating and freezing microscope stages on the market. Professor Dubois commented "A very particular use of the Linkam stage in the LGCgE laboratory is the determination of hydrate properties at low temperature. Hydrates are compounds generally stable at temperature below 0°C. Using the Linkam stage allows us to nucleate these minerals and to determine their stability field. The Linkam stage is used in combination with a Raman microspectrometer in order to record the spectra at varying temperatures. The high temperature stability is a key property to record such spectra during a few minutes or tens of minutes."

He continued "as a part of our research we have used the Linkam stage combined with Raman to study lithium-bearing solutions, whose hydrates are stable down to -77°C (Dubois et al., 2010) and created theoretical phase diagrams. The stage allowed us to conclude that high concentration calcic brines have played a major role in the formation process (Hulin et al., 2013)."