Hydrogen in fluid inclusion in ultramafic rock

Energy is one of the most critical aspects of modern life. The consumption of energy, whether in the form of electricity or combustion, forms the foundation of our prosperity and future prospects. The limited availability of energy, combined with the highly polluting by-products of its use, is driving the search for new, clean energy sources. Hydrogen is considered one of the alternatives to conventional energy sources, as its combustion produces only pure water. Although hydrogen is the most abundant element in the universe, it appears to be nearly absent on Earth. Hydrogen can be produced through industrial chemical processes, which, however, diminish the perceived cleanness of this energy source. Recently, natural hydrogen has been observed in many seeps on Earth. Analyses of gases released by specific rocks indicate that ultramafic rocks, such as Earth`s mantle material, may contain hydrogen. This gas can freely circulate through the pore spaces within the rock and may also be trapped in crystals as fluid inclusions. Fluid inclusions are valuable for understanding geological processes involving a fluid phase and can remain preserved for millions of years. The properties of the trapped fluids provide insights into the conditions of entrapment, thereby shedding light on the associated geological processes. Hydrogen-bearing inclusions were observed in rocks from Troodos (Cyprus) during a preliminary study. Troodos is a mountainous region containing the typical rock types that, in theory, may form and release large amounts of natural hydrogen. First, the present study will aim to identify the exact localities where hydrogen occurs, primarily through the observation and analysis of fluid inclusions in crystals collected in the field. The second part of this research proposal involves an experimental study to evaluate the reliability of fluid inclusions. Specifically, if you find and analyse an inclusion that has trapped fluid at a certain depth and higher temperatures, can you be certain that it has not changed before being analysed in the laboratory? In other words, is a fluid inclusion truly a closed system? Hydrogen is a small molecule capable of diffusing easily through crystals at higher temperatures. The presence of hydrogen in inclusions demonstrates that this diffusion becomes ineffective below certain conditions, which will be determined in the experimental study.