Evolution of mine caves in soluble rocks driven by deep-seated settings

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Permeability in soluble rocks increases significantly with time. While the primary permeability is controlled by the initial pore and fracture space, the fluid circulating through soluble rocks can remove material from pore and fracture surfaces, increasing the interconnected void space in the rock and thus creating a secondary permeability, often orders of magnitude larger than the primary permeability. When the mass transfer in soluble rocks creates focused flow through enlarged conduits, we often refer to the system as karst. The enlargement of fractures and pore spaces is called speleogenesis. The temporal evolution of karst is driven by flow. Depending on the origin of the fluid, we distinguish epigenetic and hypogenetic karst evolution, the former with flow from above the soluble rock formation, the latter with flow from below. While epigenetic karst evolution is well understood and dominates the literature, hypogenetic karst evolution is more elusive. The reason is often the restricted accessibility of karst structures developed under hypogene settings. We propose to develop numerical models, coupling flow, transport and reaction, which describe the temporal evolution of a species type of caves, mine caves, discovered by mining and often developed under hypogenetic conditions. We use a variety of locations (from Germany) to derive a setup and appropriate boundary conditions. Focusing on two different aspects, the chemistry and the flow in mine-cave settings, we want to learn about the processes leading to mine-cave formation in a quantitative way.