Tectono-magmatogenering structures in zones of increased geodynamic instability as priority objects for exploration of hydrogen fields

Abstract

Based on comparison of the migration activity of hydrocarbons, helium and hydrogen, the paper substantiates the types of cap rocks for hydrogen accumulations (pools), which most of all contributes to its partial shieldingat steady feed. Such cap rocks are represented by predominantly smectite clay, pure (without inclusions) salt at depths over 1—2 km, non-fractured quartz sandstone at depths over 4 km, effusive and hypabissal intrusive rocks, as well as basement rocks undisturbed by metamorphic decomposition processes. Endogenous hydrogen isconsidered as the main factor of dissipative structures formation. Occurrence of hydrogen, hydrocarbon and ore macro accumulations is a kind of energy, information-geochemical fluctuations, which are intermediate states of dissipative structures subordinated to the planetary heat and mass transfer processes caused by the deep Earth degassing. In this context, the nature of geodynamic instability (activation of vertical movements, shifts, tensile and compressive stresses) can be considered as a growing sequence of dissipative processes associated with the energy percolation role of endogenous hydrogen. In the hierarchy of ring structures (RS) (from minor depressions to large structures of dozens kilometres in diameter) special attention should be paid to Sribne RS within the Dnieper-Donets Basin and Kaluga RS within the SW part of the Voronezh anteclisepericline. These ring structuresare genetically related to explosion or volcanic calderas, and characterized by ancient origin (Proterozoic) and long-term development, including neo- and actuotectonic stages. Intensity of hydrogen degassing in the Sribne RSis confirmed by micro- and nano-inclusions in the black-shale domanicoid rocks of the productive horizons in the form of particles of native metals(including oxyphile elements Al, Zn, W and others), natural alloys and intermetallids, which are tracers of ascending flows of deep reduced fluids. It is reasonable to assume the occurrence of a large hydrogen or helium-hydrogen field (group of fields) within the Sribne RS in the Lower Visean, Lower Bashkirian and Lower Permian aged rocks, which are shielded by the Lower Permian salt deposits.