scharge area)Springs (groundwater emerging at the surface)* caused by intersection of water table with the surface (edge of 2 layers)* most major springs emerge from lava, limestone, or gravel* appear via-aquicludes- impermeable unit-aquifers- permeable unit in saturated zonepermeable sediments and rocks* sand and course sediments* sandstone* limestone* jointed lava flow* jointed graniteimpermeable rocks* clay* mudstone* unjointed granite* bedrockWells (drilled to intersect water table) (zone of saturation)* cone of depression- conical depression of water table surrounding well* perched water body- different confined aquifers at different depthsAquifers (body of highly permeable rock or regolith w/in the zone of saturation)types of aquifers* unconfined aquifer- its upper surface coincides with the water table-30% of water from high plains aquifer* confined aquifer- aquifer bounded by aquicludes-Dakota aquifer* artesian aquifer- confined aquifer under hydrostatic pressure-water can rise in artesian well to height of recharge area* complex regional aquifer- system of unconfined/confined aquifers connected by atrtesian aaquifers-Floridian aquiferEnvironmental StuffMining Groundwater (major source of freshwater, non-renewable resource)lowering of the water table* due to excessive consumption* causes land subsidence (artesian pressure supports rock weight above)* artificial recharge (spraying of biodegradable liquid waste)Water Qualitychemistry of groundwater (dissolved components)* chlorites* sulfates* bicarbonates of Ca, Mg, Na, K, Fe-soft water vs. hard water: Ca, Mg* hydrogen sulfide* salts (NaCl)Groundwater Contamination* sewage* seawater* toxic wastes* agricultural poisons* underground storage of hazardous wastesGeologic Activity of Groundwater* dissolution- chemical weathering in soil (carbonate rocks) (carbonic acid)-limestone (completely away), dolostone, and marble-exceeds avg. erosion of mass wasting, sheet erosion, and streams-10...
