| Title | Hierarchy System of Geothermal Structures--A New Outlook on Generation and Transport of Geothermal Energy in Modern Volcanic Areas |
|---|---|
| Authors | Rychagov, S. N.; Belousov, V. I.; Belousova, S. P. |
| Year | 2006 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Resource Characterization; geothermal, mineral, resources, hydrothermal-magmatic systems |
| Abstract | It is demonstrated that geothermal resources of modern volcanic areas are distinctly confined to the hierarchic system of geological structures: geothermal provinces – geothermal districts – hydrothermal-magmatic systems – geothermal reservoirs (deposits). Geothermal provinces are geological structures of graben-syncline types which control regional conductive and convective heat flows. Geothermal districts are identified with long-existing volcanogenic ore centers (centers of endogenic activity) that appear on the surface as oval-circular megastructures with a diameter of 18-24 to more than 40 km. Hydrothermal-magmatic systems are crustal permeable axisymmetrical geologic structures of the type of large volcanic-tectonic structures up to more than 18-24 km in plan and forming a distinctive self-insulated convection cell (Geothermal …, 2005). Geothermal reservoirs (deposits) are not only geological-economic conception, but also represent a system of joint upstanding and downthrown tectonic blocks with a thickness of up to n x 100 m, which control local flows of ascending fluids and descending meteoric (mixed) waters. Geothermal deposits, as a rule, are located in the central parts of hydrothermal-magmatic systems, which is determined by the position of a heat (fluid) source. The paper addresses the geological setting of geothermal provinces–districts–systems– deposits, heat (ore – fluid) feed sources, hydrothermal metamorphism of rocks, dynamics of gas-liquid and water flows, a role of gases in geology of hydrothermal-magmatic systems and in heat transport, possible heat energy storage and transfer mechanisms, etc. A model for hierarchy system of geothermal structures is suggested (from regional to local) to be built upon when applying a geological approach to assessment of prospective energy and mineral resources of modern volcanic areas. |