What geological feature primarily affects the storage and movement of groundwater?

The correct answer, sedimentary layers, plays a crucial role in the storage and movement of groundwater due to their porosity and permeability characteristics. Sedimentary rocks, such as sandstone and limestone, are often formed in environments where sediment accumulates, making them well-suited for storing water in the spaces between grains. These layers can also contain aquifers, which are underground layers of water-bearing rock that allow water to flow through them.

Additionally, sedimentary layers can serve as aquitards, which are less permeable layers that can impede the flow of groundwater. This interplay between more permeable and less permeable sedimentary layers allows for the regulation of groundwater movement and contributes to groundwater storage capacity. As such, sedimentary formations are integral to the hydrology of an area, significantly impacting how groundwater is managed and utilized.

In contrast, granite formations, igneous rocks, and metamorphic layers generally have lower porosity and permeability, which limits their ability to store and transmit groundwater effectively. Consequently, these geological features do not significantly influence groundwater dynamics as sedimentary layers do.