Final answer:
Permeability is the ability of a geologic material to transport fluids, dependent on the connectivity of the material's pores. High permeability allows for fluid flow, as seen in aquifers, while low permeability causes confinement, as in certain sedimentary rocks.
Step-by-step explanation:
Permeability refers to the capacity of a geologic material to transport fluids. This property of permeability is not solely based on the porosity of the material, which is the volume of open spaces within a rock, but also on how those spaces are connected. If the open spaces are not interconnected, fluids cannot pass through, making the material impermeable. For example, aquifers like sandstone and limestone, have both high porosity and permeability, making them excellent at yielding water. Conversely, shale and other un-fractured rocks act as confining layers due to their low permeability, which inhibits fluid flow.
Understanding permeability and porosity is vital for various geological and engineering applications, such as groundwater management, oil and gas extraction, and constructing stable foundations for buildings.