The fractured rock aquifers of the Gulf Islands are broadly comprised of sandstone and mudstone, with some volcanics (on Salt Spring Island). The geological map of Salt Spring Island was prepared by ...

That is the Ogallala Aquifer. The subsurface reservoirs trapped between fractured layers of rock and soil saved this region after the infamous Dust Bowl, and remain the source of economic life in ...

gravel or fractured rock, allowing water to flow through them. Much of Oregon's drinking water, as well as water for agriculture and industry, is fed by aquifers high up in the Cascades.