Karstni tip izdani
Izdan formirana u sistemima rastvorljivim u vodi, odnosno, u stenama sa kavernoznom ili disolucionom poroznošću. U njoj podzemna voda teče ili može teći kroz pukotine, rasede, međuslojne prostore i različite šupljine, proširene procesima rastvaranja. Od karstnih izdani, najveće rasprostranjenje ima izdan u karbonatnim naslagama, dok su u rastvorljivim hloridnim i sulfatnim naslagama, izdani manje zastupljene. Karakteriše se velikim oscilacijama nivoa podzemnih voda, kao i velikom izdašnošću izvora preko kojih se drenira. Predstavlja značajan izvor kvalitetnih podzemnih voda koje su našle primenu u vodosnabdevanju stanovništva i industrije.
Karst aquifer
Karst aquifers are water-bearing, soluble rock layers at or near the earth`s sufrace in which groundwater flow is concentrated along secondarily enlarged fractures, fissures, conduits, and other interconnected openings. They are formed by the chemical dissolving action of slightly acidic water on highly soluble rocks, most notably limestone and dolomite, and to a lesser degree, gypsum, anhydrite, and halite. For the processes of karst to be active, water must dynamically circulate through these soluble rocks – exposing the rock to interaction with water and enabling transport of solutes, and the water must be undersaturated with respect to the chemical constituents of the rock – enabling dissolution to occur. This interplay of flow (hydrology) and dissolution (geochemistry) removes rock, creating increasingly larger voids along the pathways the water follows through time. Karst aquifer development commonly results in distinctive landforms, but visible surface features are not an essential attribute of karst, because in many instances, the surface features may be covered by soil or regolith.
Rečnik geoloških termina i pojmova Geološkog informacionog sistema Srbije, Beograd, 2011. Geološka klasifikacija/Osnovna hidrogeološka terminologija i klasifikacije/ p. 353
